SGP/MWR/B5 - wrong calibration

An upgrade of the instrument by the manufacturer significantly changed its 
calibration and the configuration file was not updated with the new calibration
values when the instrument was returned to service.

• null(Raw data stream - documentation not supported)

• IR Brightness Temperature(ir_temp)
• Time offset of tweaks from base_time(time_offset)
• Water on Teflon window (1=WET, 0=DRY)(wet_window)
• MWR column precipitable water vapor(vap)
• Dummy altitude for Zeb(alt)
• Actual elevation angle(actel)
• Actual Azimuth(actaz)
• base time(base_time)
• 31.4 GHz sky brightness temperature(31tbsky)
• Averaged total liquid water along LOS path(liq)
• lat(lat)
• lon(lon)
• 23.8 GHz sky brightness temperature(23tbsky)

• Actual Azimuth(actaz)
• Blackbody kinetic temperature(tkbb)
• 23.8 GHz Blackbody signal(bb23)
• Temperature correction coefficient at 31.4 GHz(tc31)
• Ambient temperature(tkair)
• 23.8 GHz sky signal(tipsky23)
• Water on Teflon window (1=WET, 0=DRY)(wet_window)
• 23.8 GHz goodness-of-fit coefficient(r23)
• Noise injection temp at nominal temperature at 23.8 GHz(tnd_nom23)
• lat(lat)
• Noise injection temp at 23.8 GHz adjusted to tkbb(tnd23)
• 31.4 GHz sky signal(tipsky31)
• (tknd)
• Noise injection temp at 31.4 GHz adjusted to tkbb(tnd31)
• 31.4 GHz goodness-of-fit coefficient(r31)
• 23.8 GHz blackbody+noise injection signal(bbn23)
• Noise injection temp at 31.4 GHz derived from this tip(tnd31I)
• Temperature correction coefficient at 23.8 GHz(tc23)
• 31.4 GHz blackbody(bb31)
• Noise injection temp at nominal temperature at 31.4 GHz(tnd_nom31)
• Mixer kinetic (physical) temperature(tkxc)
• lon(lon)
• Noise injection temp at 23.8 GHz derived from this tip(tnd23I)
• Actual elevation angle(actel)
• Time offset of tweaks from base_time(time_offset)
• base time(base_time)
• 31.4 GHz blac2body+noise injection signal(bbn31)
• Dummy altitude for Zeb(alt)

• lon(lon)
• Standard deviation about the mean for the 31.4 GHz sky brightness temperature(tbsky31_sdev)
• base time(base_time)
• Averaged total liquid water along LOS path(liq)
• Fraction of data in averaging interval with water on Teflon window(water_flag_fraction)
• IR Brightness Temperature(ir_temp)
• Dummy altitude for Zeb(alt)
• 31.4 GHz sky brightness temperature(31tbsky)
• Standard deviation about the mean for the total water vapor amount(vap_sdev)
• Standard deviation about the mean for the IR brightness temperature(ir_temp_sdev)
• Time offset of tweaks from base_time(time_offset)
• lat(lat)
• 23.8 GHz sky brightness temperature(23tbsky)
• Standard deviation about the mean for the total liquid water amount(liq_sdev)
• Standard deviation about the mean for the 23.8 GHz sky brightness temperature(tbsky23_sdev)
• Number of data points averaged for 23tbsky, 31tbsky, vap & liq(num_obs)
• MWR column precipitable water vapor(vap)

• Time offset of tweaks from base_time(time_offset)
• IR Brightness Temperature(ir_temp)
• Water on Teflon window (1=WET, 0=DRY)(wet_window)
• Averaged total liquid water along LOS path(liq)
• lat(lat)
• Sky brightness temperature at 23.8 GHz(tbsky23)
• Dummy altitude for Zeb(alt)
• base time(base_time)
• MWR column precipitable water vapor(vap)
• Sky brightness temperature at 31.4 GHz(tbsky31)
• lon(lon)

SGP/SONDE/B1 - Incorrect surface temperature

The operator entered 8.1 degC as the surface temperature for this sounding instead of -8.1 
degC.  This is the only value affected.

• null(Raw data stream - documentation not supported)

• Dry bulb temperature(tdry)

• Dry bulb temperature(tdry)

SGP/SONDE/B1 - Bad sounding data (incorrect calibration?)

I'm not sure what happened here but the temperature data for this sounding
clearly are wrong.  Along with the missing humidity data and the problems
the operator reported with his previous sounding it looks as if all the data
in this file are bad.  It may be that the sensor was damaged at launch (it
was very windy).

• null(Raw data stream - documentation not supported)

• lon(lon)
• Ascent Rate(asc)
• Time offset of tweaks from base_time(time_offset)
• Dry bulb temperature(tdry)
• Surface dew point temperature(dp)
• lat(lat)
• Dummy altitude for Zeb(alt)
• Mean Wind Speed(wspd)
• Relative humidity inside the instrument enclosure(rh)
• Wind Status(wstat)
• Retrieved pressure profile(pres)
• base time(base_time)
• Wind Direction(deg)

• Surface dew point temperature(dp)
• Wind Status(wstat)
• lon(lon)
• Retrieved pressure profile(pres)
• V-component(v_wind)
• Time offset of tweaks from base_time(time_offset)
• Relative humidity inside the instrument enclosure(rh)
• Dummy altitude for Zeb(alt)
• Mean Wind Speed(wspd)
• Dry bulb temperature(tdry)
• base time(base_time)
• lat(lat)
• Wind Direction(deg)
• Ascent Rate(asc)
• U-component(u_wind)

SGP/SONDE/C1 - Bad temp (other?) data in 12/3/01:2328 sounding

It looks as though the temperature sensor was damaged on launch.  The
recorded temp goes from 16.4 at the surface to -42.6 at 2 seconds into the
flight.  The temperature never exceeds -42 though the RH and pressure look
reasonable, but probably should be considered questionable.

• null(Raw data stream - documentation not supported)

• Dry bulb temperature(tdry)
• Relative humidity inside the instrument enclosure(rh)
• Surface dew point temperature(dp)

• Surface dew point temperature(dp)
• Dry bulb temperature(tdry)
• Relative humidity inside the instrument enclosure(rh)

• null(Raw data stream - documentation not supported)

overlapping files report different values

The sgp5mwravgB5.c1 data file for this day was split into
two files (both partial days).  The first file contains
data for 990913.145500-990913.170000.  The second file
contains data for 990913.170000-990913.173000.  The two
files report different values the the 170000 time stamp.

• Fraction of data in averaging interval flagged by Dynamic Linear Model as poten(dlm_flag_fraction)
• Number of data points averaged for ir_temp(num_obs_ir)
• base time(base_time)
• lon(lon)
• Standard deviation about the mean for the total liquid water amount(liq_sdev)
• Standard deviation about the mean for the total water vapor amount(vap_sdev)
• Averaged total liquid water along LOS path(liq)
• Standard deviation about the mean for the 23.8 GHz sky brightness temperature(tbsky23_sdev)
• Standard deviation about the mean for the IR brightness temperature(ir_temp_sdev)
• Fraction of data in averaging interval with water on Teflon window(water_flag_fraction)
• Number of points included in the ir_temp ensemble(num_obs_irt)
• IR Brightness Temperature(ir_temp)
• Time offset of tweaks from base_time(time_offset)
• Number of data points averaged for 23tbsky, 31tbsky, vap & liq(num_obs)
• Sky brightness temperature at 31.4 GHz(tbsky31)
• Dummy altitude for Zeb(alt)
• lat(lat)
• MWR column precipitable water vapor(vap)
• Standard deviation about the mean for the 31.4 GHz sky brightness temperature(tbsky31_sdev)
• Sky brightness temperature at 23.8 GHz(tbsky23)
• Number of contiguous periods in averaging interval flagged by Dynamic Linear Mo(dlm_flag_periods)
• 23.8 GHz sky brightness temperature(23tbsky)
• Number of contiguous periods in averaging interval with water on Teflon window(water_flag_periods)
• 31.4 GHz sky brightness temperature(31tbsky)

SGP/SONDE/C1 - Bad temperature in CF sounding 12/22/01:0527

The temperature data in this sounding look bad after the first value.  The
temperature series is 11.4, 2.6, -14.3, -32.4 in the first 6 seconds of
flight.  I don't know why this occurred, but it obviously is incorrect.
The pressure and RH data look reasonable.

• Dry bulb temperature(tdry)
• Surface dew point temperature(dp)

• Surface dew point temperature(dp)
• Dry bulb temperature(tdry)

SGP/SONDE/C1 - Bad temperature data CF sounding 12/28/01:2326

The temperature data in this sounding are bad from approximately 16 seconds
into the flight.  The temperature series is 9.9, 10.8, 11.3, 1.5, 11.6, 11.6,
11.6, -32.2 and remains below -30 degC.  I don't know why this occurred, but
it clearly is incorrect.  The pressure data looks OK as does the RH, though
the RH data are missing (probably sensor failure) above roughly 3.5 km.

• Dry bulb temperature(tdry)
• Surface dew point temperature(dp)

• Surface dew point temperature(dp)
• Dry bulb temperature(tdry)

SGP/SONDE/C1 - Bad temperature in SGP/CF sounding 20020108:0528

Temperature values in this sounding went from 3.5 degC at the surface to
-33.3 degC at the next sample.  It appears that all the remaining
temperature values have an approximate -35 degC offset.  The pressure
and RH values appear reasonable.

• Dry bulb temperature(tdry)
• Surface dew point temperature(dp)

• Surface dew point temperature(dp)
• Dry bulb temperature(tdry)

SGP/SONDE/C1 - CF sounding 20020522:1130 bad temperature/RH

It appears that the sonde sensor boom was damaged upon launch.  The result
is that no RH data are reported and the reported temperature is something on
the order of 60 degC too low.

• Dry bulb temperature(tdry)
• Dummy altitude for Zeb(alt)
• Relative humidity inside the instrument enclosure(rh)
• Ascent Rate(asc)
• Surface dew point temperature(dp)

• Surface dew point temperature(dp)
• Dry bulb temperature(tdry)
• Relative humidity inside the instrument enclosure(rh)
• Ascent Rate(asc)
• Dummy altitude for Zeb(alt)

SGP/SONDE/C1 - Bad T/RH data in CF sounding 20020523:1129

It appears that the sensor boom was damaged shortly after launch.  The
temperature reading jumps -60 degC and the RH goes to 0.

• Dry bulb temperature(tdry)
• Dummy altitude for Zeb(alt)
• Relative humidity inside the instrument enclosure(rh)
• Ascent Rate(asc)
• Surface dew point temperature(dp)

• Surface dew point temperature(dp)
• Dry bulb temperature(tdry)
• Relative humidity inside the instrument enclosure(rh)
• Ascent Rate(asc)
• Dummy altitude for Zeb(alt)

SGP/SONDE/C1 - CF sounding 20020609:0229 bad temp/rh/etc

The temperature and RH for this sounding look bad, either because of
interference from another sonde or because the temperature sensor was
broken on launch.  The sounding terminated early in any event.

• Dry bulb temperature(tdry)
• Dummy altitude for Zeb(alt)
• Relative humidity inside the instrument enclosure(rh)
• Ascent Rate(asc)
• Surface dew point temperature(dp)

• Surface dew point temperature(dp)
• Dry bulb temperature(tdry)
• Relative humidity inside the instrument enclosure(rh)
• Ascent Rate(asc)
• Dummy altitude for Zeb(alt)

SGP/SONDE/C1 - Incorrect Surface Pressure

It appears that the operator made a typographical error when entering the
surface pressure.  The file has 987.0 hPa and it probably should be 978.0
which would be consistent with the first sample provided by the radiosonde
(977.3 hPa), the surface pressures recorded for the adjacent soundings, and
the THWAPS pressure.

Because the sounding altitude is calculated assuming the surface pressure
is correct, the altitude values for the entire flight and the ascent rate 
values for the first 30 seconds of the sounding will be incorrect.

• Dummy altitude for Zeb(alt)
• Ascent Rate(asc)

• Ascent Rate(asc)
• Dummy altitude for Zeb(alt)

SGP/SONDE/C1 - Bad Temperature Sensor

It appears that the temperature sensor broke shortly after launch.  As a
result, the temperature and dewpoint values are incorrect.

• Dry bulb temperature(tdry)
• Relative humidity inside the instrument enclosure(rh)
• Surface dew point temperature(dp)

• Surface dew point temperature(dp)
• Dry bulb temperature(tdry)
• Relative humidity inside the instrument enclosure(rh)

SGP/SONDE/C1 - Temperature sensor failure

Temperature sensor broke at launch.  All temperature-related variables
are incorrect.

• Dry bulb temperature(tdry)
• Relative humidity inside the instrument enclosure(rh)
• Surface dew point temperature(dp)

• Surface dew point temperature(dp)
• Dry bulb temperature(tdry)
• Relative humidity inside the instrument enclosure(rh)

• Integrated vapor column from sonde using MWR Instrument Performance Model (IPM)(integ_vap_sonde)
• Integrated vapor column from sonde using a direct calculation (external from the
  IPM)(integ_vap_sonde_direct)

SGP/MWR/B6 - Instrument replaced, calibration incorrect

MWR serial number 18 was replaced with MWR serial number 04 at 1652 on 2 Aug 2002.  
Between this time and 2214, when a sufficient number of new tip curves were acquired to update 
the calibration, the old calibration (for serial number 18) was used.  During this period 
the data are incorrect.

• 23.8 GHz Blackbody signal(bb23)
• MWR column precipitable water vapor(vap)
• Mixer kinetic (physical) temperature(tkxc)
• Sky Infra-Red Temperature(sky_ir_temp)
• 31.4 GHz blackbody(bb31)
• lat(lat)
• (tknd)
• 31.4 GHz sky signal(sky31)
• Noise injection temp at 23.8 GHz adjusted to tkbb(tnd23)
• 31.4 GHz blac2body+noise injection signal(bbn31)
• Averaged total liquid water along LOS path(liq)
• Sky brightness temperature at 23.8 GHz(tbsky23)
• Temperature correction coefficient at 31.4 GHz(tc31)
• Water on Teflon window (1=WET, 0=DRY)(wet_window)
• lon(lon)
• Dummy altitude for Zeb(alt)
• Ambient temperature(tkair)
• Blackbody kinetic temperature(tkbb)
• 23.8 GHz blackbody+noise injection signal(bbn23)
• Temperature correction coefficient at 23.8 GHz(tc23)
• Noise injection temp at 31.4 GHz adjusted to tkbb(tnd31)
• IR Brightness Temperature(ir_temp)
• base time(base_time)
• 23.8 GHz sky signal(sky23)
• Noise injection temp at nominal temperature at 23.8 GHz(tnd_nom23)
• Time offset of tweaks from base_time(time_offset)
• Sky brightness temperature at 31.4 GHz(tbsky31)
• Noise injection temp at nominal temperature at 31.4 GHz(tnd_nom31)

• Dummy altitude for Zeb(alt)
• Fraction of data in averaging interval flagged by Dynamic Linear Model as poten(dlm_flag_fraction)
• 31.4 GHz sky brightness temperature(31tbsky)
• Number of points included in the ir_temp ensemble(num_obs_irt)
• Standard deviation about the mean for the total water vapor amount(vap_sdev)
• Standard deviation about the mean for the 23.8 GHz sky brightness temperature(tbsky23_sdev)
• lon(lon)
• base time(base_time)
• Sky brightness temperature at 31.4 GHz(tbsky31)
• Standard deviation about the mean for the IR brightness temperature(ir_temp_sdev)
• Averaged total liquid water along LOS path(liq)
• Number of data points averaged for 23tbsky, 31tbsky, vap & liq(num_obs)
• Number of contiguous periods in averaging interval flagged by Dynamic Linear Mo(dlm_flag_periods)
• Fraction of data in averaging interval with water on Teflon window(water_flag_fraction)
• Standard deviation about the mean for the total liquid water amount(liq_sdev)
• Time offset of tweaks from base_time(time_offset)
• lat(lat)
• Number of contiguous periods in averaging interval with water on Teflon window(water_flag_periods)
• 23.8 GHz sky brightness temperature(23tbsky)
• Sky brightness temperature at 23.8 GHz(tbsky23)
• Number of data points averaged for ir_temp(num_obs_ir)
• IR Brightness Temperature(ir_temp)
• Standard deviation about the mean for the 31.4 GHz sky brightness temperature(tbsky31_sdev)
• MWR column precipitable water vapor(vap)

• Mixer kinetic (physical) temperature(tkxc)
• Which LOS configuration(losn)
• Actual elevation angle(actel)
• 23.8 GHz sky+noise injection signal(23skyn)
• 23.8 GHz Blackbody signal(23bb)
• Averaged total liquid water along LOS path(liq)
• 31.4 GHz blackbody(bb31)
• Time offset of tweaks from base_time(time_offset)
• 23.8 GHz sky brightness temperature(23tbsky)
• Noise injection temp at nominal temperature at 23.8 GHz(noise_injection_temp_23)
• 31.4 GHz blackbody+noise injection signal(31bbn)
• Temperature correction coefficient at 31.4 GHz(temperature_correction_coef_31)
• 23.8 GHz blackbody+noise injection signal(23bbn)
• IR Brightness Temperature(ir_temp)
• Noise injection temp at nominal temperature at 31.4 GHz(noise_injection_temp_31)
• Ambient temperature(tkair)
• 23.8 GHz noise injection brightness temperature(23unoise)
• base time(base_time)
• 23.8 GHz sky signal(sky23)
• Actual Azimuth(actaz)
• 31.4 GHz blac2body+noise injection signal(bbn31)
• 31.4 GHz blackbody(31bb)
• 23.8 GHz blackbody+noise injection signal(bbn23)
• 23.8 GHz sky signal(23sky)
• 23.8 GHz Blackbody signal(bb23)
• MWR column precipitable water vapor(vap)
• 31.4 GHz sky+noise injection signal(31skyn)
• Sky brightness temperature at 23.8 GHz(tbsky23)
• Water on Teflon window (1=WET, 0=DRY)(wet_window)
• Blackbody kinetic temperature(tkbb)
• lon(lon)
• Sky brightness temperature at 31.4 GHz(tbsky31)
• (tknd)
• 31.4 GHz noise injection brightness temperature(31unoise)
• 31.4 GHz sky signal(sky31)
• 31.4 GHz sky brightness temperature(31tbsky)
• Temperature correction coefficient at 23.8 GHz(temperature_correction_coef_23)
• Dummy altitude for Zeb(alt)
• 31.4 GHz sky signal(31sky)
• Noise injection temp at 31.4 GHz adjusted to tkbb(tnd31)
• Noise injection temp at 23.8 GHz adjusted to tkbb(tnd23)
• lat(lat)

• Time offset of tweaks from base_time(time_offset)
• Blackbody kinetic temperature(tkbb)
• base time(base_time)
• Averaged total liquid water along LOS path(liq)
• IR Brightness Temperature(ir_temp)
• Temperature correction coefficient at 23.8 GHz(tc23)
• MWR column precipitable water vapor(vap)
• Dummy altitude for Zeb(alt)
• lat(lat)
• Water on Teflon window (1=WET, 0=DRY)(wet_window)
• Sky brightness temperature at 31.4 GHz(tbsky31)
• Sky brightness temperature at 23.8 GHz(tbsky23)
• Actual elevation angle(actel)
• Sky Infra-Red Temperature(sky_ir_temp)
• 31.4 GHz blackbody(bb31)
• 23.8 GHz sky brightness temperature(23tbsky)
• 31.4 GHz blac2body+noise injection signal(bbn31)
• 23.8 GHz sky signal(sky23)
• 23.8 GHz blackbody+noise injection signal(bbn23)
• Noise injection temp at 23.8 GHz adjusted to tkbb(tnd23)
• lon(lon)
• (tknd)
• Temperature correction coefficient at 31.4 GHz(tc31)
• Noise injection temp at 31.4 GHz adjusted to tkbb(tnd31)
• Noise injection temp at nominal temperature at 31.4 GHz(tnd_nom31)
• Actual Azimuth(actaz)
• Mixer kinetic (physical) temperature(tkxc)
• Ambient temperature(tkair)
• Noise injection temp at nominal temperature at 23.8 GHz(tnd_nom23)
• 23.8 GHz Blackbody signal(bb23)
• 31.4 GHz sky brightness temperature(31tbsky)
• 31.4 GHz sky signal(sky31)

SGP/MWR/B6 - Instrument replaced, calibration updating

Following replacement of the MWR at B6, an automatically and continuously upated median 
calibration value was used based on data acquired during this period.  After this period, 
sufficient tip curves were available to automatically and continuously determine and 
account for the temperature dependence of the calibration.

• 23.8 GHz Blackbody signal(bb23)
• MWR column precipitable water vapor(vap)
• Mixer kinetic (physical) temperature(tkxc)
• Sky Infra-Red Temperature(sky_ir_temp)
• 31.4 GHz blackbody(bb31)
• lat(lat)
• (tknd)
• 31.4 GHz sky signal(sky31)
• Noise injection temp at 23.8 GHz adjusted to tkbb(tnd23)
• 31.4 GHz blac2body+noise injection signal(bbn31)
• Averaged total liquid water along LOS path(liq)
• Sky brightness temperature at 23.8 GHz(tbsky23)
• Temperature correction coefficient at 31.4 GHz(tc31)
• Water on Teflon window (1=WET, 0=DRY)(wet_window)
• lon(lon)
• Dummy altitude for Zeb(alt)
• Ambient temperature(tkair)
• Blackbody kinetic temperature(tkbb)
• 23.8 GHz blackbody+noise injection signal(bbn23)
• Temperature correction coefficient at 23.8 GHz(tc23)
• Noise injection temp at 31.4 GHz adjusted to tkbb(tnd31)
• IR Brightness Temperature(ir_temp)
• base time(base_time)
• 23.8 GHz sky signal(sky23)
• Noise injection temp at nominal temperature at 23.8 GHz(tnd_nom23)
• Time offset of tweaks from base_time(time_offset)
• Sky brightness temperature at 31.4 GHz(tbsky31)
• Noise injection temp at nominal temperature at 31.4 GHz(tnd_nom31)

• Dummy altitude for Zeb(alt)
• Fraction of data in averaging interval flagged by Dynamic Linear Model as poten(dlm_flag_fraction)
• 31.4 GHz sky brightness temperature(31tbsky)
• Number of points included in the ir_temp ensemble(num_obs_irt)
• Standard deviation about the mean for the total water vapor amount(vap_sdev)
• Standard deviation about the mean for the 23.8 GHz sky brightness temperature(tbsky23_sdev)
• lon(lon)
• base time(base_time)
• Sky brightness temperature at 31.4 GHz(tbsky31)
• Standard deviation about the mean for the IR brightness temperature(ir_temp_sdev)
• Averaged total liquid water along LOS path(liq)
• Number of data points averaged for 23tbsky, 31tbsky, vap & liq(num_obs)
• Number of contiguous periods in averaging interval flagged by Dynamic Linear Mo(dlm_flag_periods)
• Fraction of data in averaging interval with water on Teflon window(water_flag_fraction)
• Standard deviation about the mean for the total liquid water amount(liq_sdev)
• Time offset of tweaks from base_time(time_offset)
• lat(lat)
• Number of contiguous periods in averaging interval with water on Teflon window(water_flag_periods)
• 23.8 GHz sky brightness temperature(23tbsky)
• Sky brightness temperature at 23.8 GHz(tbsky23)
• Number of data points averaged for ir_temp(num_obs_ir)
• IR Brightness Temperature(ir_temp)
• Standard deviation about the mean for the 31.4 GHz sky brightness temperature(tbsky31_sdev)
• MWR column precipitable water vapor(vap)

• Mixer kinetic (physical) temperature(tkxc)
• Which LOS configuration(losn)
• Actual elevation angle(actel)
• 23.8 GHz sky+noise injection signal(23skyn)
• 23.8 GHz Blackbody signal(23bb)
• Averaged total liquid water along LOS path(liq)
• 31.4 GHz blackbody(bb31)
• Time offset of tweaks from base_time(time_offset)
• 23.8 GHz sky brightness temperature(23tbsky)
• Noise injection temp at nominal temperature at 23.8 GHz(noise_injection_temp_23)
• 31.4 GHz blackbody+noise injection signal(31bbn)
• Temperature correction coefficient at 31.4 GHz(temperature_correction_coef_31)
• 23.8 GHz blackbody+noise injection signal(23bbn)
• IR Brightness Temperature(ir_temp)
• Noise injection temp at nominal temperature at 31.4 GHz(noise_injection_temp_31)
• Ambient temperature(tkair)
• 23.8 GHz noise injection brightness temperature(23unoise)
• base time(base_time)
• 23.8 GHz sky signal(sky23)
• Actual Azimuth(actaz)
• 31.4 GHz blac2body+noise injection signal(bbn31)
• 31.4 GHz blackbody(31bb)
• 23.8 GHz blackbody+noise injection signal(bbn23)
• 23.8 GHz sky signal(23sky)
• 23.8 GHz Blackbody signal(bb23)
• MWR column precipitable water vapor(vap)
• 31.4 GHz sky+noise injection signal(31skyn)
• Sky brightness temperature at 23.8 GHz(tbsky23)
• Water on Teflon window (1=WET, 0=DRY)(wet_window)
• Blackbody kinetic temperature(tkbb)
• lon(lon)
• Sky brightness temperature at 31.4 GHz(tbsky31)
• (tknd)
• 31.4 GHz noise injection brightness temperature(31unoise)
• 31.4 GHz sky signal(sky31)
• 31.4 GHz sky brightness temperature(31tbsky)
• Temperature correction coefficient at 23.8 GHz(temperature_correction_coef_23)
• Dummy altitude for Zeb(alt)
• 31.4 GHz sky signal(31sky)
• Noise injection temp at 31.4 GHz adjusted to tkbb(tnd31)
• Noise injection temp at 23.8 GHz adjusted to tkbb(tnd23)
• lat(lat)

• Time offset of tweaks from base_time(time_offset)
• Blackbody kinetic temperature(tkbb)
• base time(base_time)
• Averaged total liquid water along LOS path(liq)
• IR Brightness Temperature(ir_temp)
• Temperature correction coefficient at 23.8 GHz(tc23)
• MWR column precipitable water vapor(vap)
• Dummy altitude for Zeb(alt)
• lat(lat)
• Water on Teflon window (1=WET, 0=DRY)(wet_window)
• Sky brightness temperature at 31.4 GHz(tbsky31)
• Sky brightness temperature at 23.8 GHz(tbsky23)
• Actual elevation angle(actel)
• Sky Infra-Red Temperature(sky_ir_temp)
• 31.4 GHz blackbody(bb31)
• 23.8 GHz sky brightness temperature(23tbsky)
• 31.4 GHz blac2body+noise injection signal(bbn31)
• 23.8 GHz sky signal(sky23)
• 23.8 GHz blackbody+noise injection signal(bbn23)
• Noise injection temp at 23.8 GHz adjusted to tkbb(tnd23)
• lon(lon)
• (tknd)
• Temperature correction coefficient at 31.4 GHz(tc31)
• Noise injection temp at 31.4 GHz adjusted to tkbb(tnd31)
• Noise injection temp at nominal temperature at 31.4 GHz(tnd_nom31)
• Actual Azimuth(actaz)
• Mixer kinetic (physical) temperature(tkxc)
• Ambient temperature(tkair)
• Noise injection temp at nominal temperature at 23.8 GHz(tnd_nom23)
• 23.8 GHz Blackbody signal(bb23)
• 31.4 GHz sky brightness temperature(31tbsky)
• 31.4 GHz sky signal(sky31)

SGP/SONDE/C1 - Bad Temperature Sensor

It appears that the temperature sensor broke upon launch and therefore the reported 
temperature is approximately 40 degC too low.

• Dry bulb temperature(tdry)
• Relative humidity inside the instrument enclosure(rh)
• Surface dew point temperature(dp)

• Surface dew point temperature(dp)
• Dry bulb temperature(tdry)
• Relative humidity inside the instrument enclosure(rh)

• Integrated vapor column from sonde using MWR Instrument Performance Model (IPM)(integ_vap_sonde)

• Relative humidity inside the instrument enclosure(rh)
• Dry bulb temperature(tdry)

SGP/SONDE/C1 - Bad Temperature Sensor

It appears that the temperature sensor broke shortly after launch. Temperatures are offset 
by approxmiately (but not constantly) 40 degC.

• Dry bulb temperature(tdry)
• Relative humidity inside the instrument enclosure(rh)
• Surface dew point temperature(dp)

• Surface dew point temperature(dp)
• Dry bulb temperature(tdry)
• Relative humidity inside the instrument enclosure(rh)

• Integrated vapor column from sonde using MWR Instrument Performance Model (IPM)(integ_vap_sonde)

• Relative humidity inside the instrument enclosure(rh)
• Dry bulb temperature(tdry)

Bad temperature sensor

It appears that the temperture sensor broke a few seconds into flight.  This results in an 
unreasonably low temperature for the rest of the flight.  For some reason, the rh values 
also go missing shortly after launch.  Only the wind and pressure data are reliable.

• Dummy altitude for Zeb(alt)
• Surface dew point temperature(dp)
• Dry bulb temperature(tdry)
• Relative humidity inside the instrument enclosure(rh)
• Ascent Rate(asc)

• Surface dew point temperature(dp)
• Relative humidity inside the instrument enclosure(rh)
• Ascent Rate(asc)
• Dry bulb temperature(tdry)
• Dummy altitude for Zeb(alt)

• Dummy altitude for Zeb(alt)
• Relative humidity inside the instrument enclosure(rh)
• Dry bulb temperature(tdry)

SGP/SONDE/B4 - Soundings contaminated by interference

These five soundings, done in succession on 11/07/2002 as part of the SCM/IOP are 
contaminated by interference.  I can't tell whether the problem has to do with improper tuning of 
the radiosondes, inadequate frequency separation among radiosondes launched from 
different locations, or some other operator problem.  I suspect that there is an operator 
component to the difficulty because the surface pressure is given as an unreasonably low 896.6 
hPa on the 1730 sounding and 886.1 hPa on the 2331 sounding.  This may indicate that the 
ground station was locked another station's radiosonde rather than on the B4 radiosonde.

• Relative humidity inside the instrument enclosure(rh)
• lon(lon)
• Retrieved pressure profile(pres)
• lat(lat)
• Dry bulb temperature(tdry)
• Dummy altitude for Zeb(alt)

• maximum height attained by the balloon in pressure units(max_height_sonde)
• MWR IPM output for 23.8 GHz sky brightness temperature using sonde T,P,RH(model_tbsky23)
• Integrated vapor column from sonde using MWR Instrument Performance Model (IPM)(integ_vap_sonde)
• MWR IPM output for atmospheric mean radiating temp using sonde T,P,RH(model_tmr31)
• MWR IPM output for 31.4 GHz sky brightness temperature using sonde T,P,RH(model_tbsky31)
• MWR IPM output for atmospheric mean radiating temp using sonde T,P,RH(model_tmr23)

• Mean Wind Speed(wspd)
• Surface dew point temperature(dp)
• lon(lon)
• lat(lat)
• V-component(v_wind)
• Dry bulb temperature(tdry)
• U-component(u_wind)
• Relative humidity inside the instrument enclosure(rh)
• Retrieved pressure profile(pres)
• Ascent Rate(asc)
• Dummy altitude for Zeb(alt)
• Wind Direction(deg)

• Dummy altitude for Zeb(alt)
• lat(lat)
• Wind Direction(deg)
• Retrieved pressure profile(pres)
• Mean Wind Speed(wspd)
• Dry bulb temperature(tdry)
• Surface dew point temperature(dp)
• V-component(v_wind)
• lon(lon)
• Ascent Rate(asc)
• Relative humidity inside the instrument enclosure(rh)
• U-component(u_wind)

SGP/SONDE/B4 - Possible interference in B4 sounding 20021110.1729

There is a strange inversion aloft in the subject sounding.  The
temperature goes from -56.3 degC to -51.5 degC in less than two
minutes (approximately .72 km).  This is somewhat below the estimated
tropopause height.  I suspect this may be an interference problem,
but note that both the recorded pressure and RH values are reasonably
continuous.  More accurate assessment would require analysis of the
absolutely raw binary data; something that would require effort beyond
the limits of my IM funding.

• null(Raw data stream - documentation not supported)

• Mean Wind Speed(wspd)
• Surface dew point temperature(dp)
• lon(lon)
• Wind Status(wstat)
• lat(lat)
• V-component(v_wind)
• Dry bulb temperature(tdry)
• U-component(u_wind)
• Relative humidity inside the instrument enclosure(rh)
• Retrieved pressure profile(pres)
• Ascent Rate(asc)
• base time(base_time)
• Time offset of tweaks from base_time(time_offset)
• Wind Direction(deg)
• Dummy altitude for Zeb(alt)

• base time(base_time)
• Dummy altitude for Zeb(alt)
• lat(lat)
• Wind Direction(deg)
• Retrieved pressure profile(pres)
• Mean Wind Speed(wspd)
• Dry bulb temperature(tdry)
• Time offset of tweaks from base_time(time_offset)
• Surface dew point temperature(dp)
• V-component(v_wind)
• lon(lon)
• Ascent Rate(asc)
• Relative humidity inside the instrument enclosure(rh)
• U-component(u_wind)
• Wind Status(wstat)

SGP/SONDE/C1 - Questionable RH: CF sounding 11/13/2002:2044

The RH data in this sounding is erratic between 2km and 10 km, oscillating between 
reasonable values (~40%RH) and zero.  I certainly doubt that this is a real, heretofore 
unreported, atmospheric phenomenon so I have to conclude that something is probably wrong with 
the sensor.  I have not seen this behavior before.  One would have to look at the 
absolutely raw RH data to explore further.

• Relative humidity inside the instrument enclosure(rh)
• Surface dew point temperature(dp)

• Surface dew point temperature(dp)
• Relative humidity inside the instrument enclosure(rh)

SGP/SONDE/B4 - B4 sounding contaminated by interference

Much of this sounding is contaminated, apparently by interference from another sonde 
signal.  It is still no clear why this seems to happen more frequently at B4 than the other 
sites, especially since the wind seems to have been from the west and B4 should be the most 
upwind station.

• null(Raw data stream - documentation not supported)

• Mean Wind Speed(wspd)
• Surface dew point temperature(dp)
• lon(lon)
• Wind Status(wstat)
• lat(lat)
• V-component(v_wind)
• Dry bulb temperature(tdry)
• U-component(u_wind)
• Relative humidity inside the instrument enclosure(rh)
• Retrieved pressure profile(pres)
• Ascent Rate(asc)
• base time(base_time)
• Time offset of tweaks from base_time(time_offset)
• Wind Direction(deg)
• Dummy altitude for Zeb(alt)

• base time(base_time)
• Dummy altitude for Zeb(alt)
• lat(lat)
• Wind Direction(deg)
• Retrieved pressure profile(pres)
• Mean Wind Speed(wspd)
• Dry bulb temperature(tdry)
• Time offset of tweaks from base_time(time_offset)
• Surface dew point temperature(dp)
• V-component(v_wind)
• lon(lon)
• Ascent Rate(asc)
• Relative humidity inside the instrument enclosure(rh)
• U-component(u_wind)
• Wind Status(wstat)

SGP/SONDE/C1 - Contaminated by interference

These three soundings are contaminated by interference from another radiosonde.  It is not 
clear why; this doesn't usually happen at the CF where the operators are very 
experienced and frequency separation is not usually a problem.

• Mean Wind Speed(wspd)
• Dummy altitude for Zeb(alt)
• V-component(v_wind)
• base time(base_time)
• Relative humidity inside the instrument enclosure(rh)
• Ascent Rate(asc)
• Wind Direction(deg)
• Wind Status(wstat)
• U-component(u_wind)
• Surface dew point temperature(dp)
• Dry bulb temperature(tdry)
• Time offset of tweaks from base_time(time_offset)
• lat(lat)
• lon(lon)
• Retrieved pressure profile(pres)

• Mean Wind Speed(wspd)
• U-component(u_wind)
• lat(lat)
• Ascent Rate(asc)
• lon(lon)
• Time offset of tweaks from base_time(time_offset)
• V-component(v_wind)
• Dummy altitude for Zeb(alt)
• Surface dew point temperature(dp)
• base time(base_time)
• Relative humidity inside the instrument enclosure(rh)
• Retrieved pressure profile(pres)
• Wind Direction(deg)
• Wind Status(wstat)
• Dry bulb temperature(tdry)

• null(Raw data stream - documentation not supported)

SGP/SONDE/B1 - Temperature sensor failed

It appears that the temperature sensor on this sonde broke shortly after launch with the 
effect that the temperatures read approximately 30 degC too low.  Other measurements that 
do not rely on the temperature, for example pressure and wind velocity, should be OK.

• Relative humidity inside the instrument enclosure(rh)
• Dry bulb temperature(tdry)
• Surface dew point temperature(dp)

• Surface dew point temperature(dp)
• Dry bulb temperature(tdry)
• Relative humidity inside the instrument enclosure(rh)

SGP/SONDE/C1 - Interference CF sounding 20021120:0225

Like several soundings on 11/19, this sounding was affected by interference from another 
radiosonde.

• Mean Wind Speed(wspd)
• Dummy altitude for Zeb(alt)
• V-component(v_wind)
• base time(base_time)
• Relative humidity inside the instrument enclosure(rh)
• Ascent Rate(asc)
• Wind Direction(deg)
• Wind Status(wstat)
• U-component(u_wind)
• Surface dew point temperature(dp)
• Dry bulb temperature(tdry)
• Time offset of tweaks from base_time(time_offset)
• lat(lat)
• lon(lon)
• Retrieved pressure profile(pres)

• Mean Wind Speed(wspd)
• U-component(u_wind)
• lat(lat)
• Ascent Rate(asc)
• lon(lon)
• Time offset of tweaks from base_time(time_offset)
• V-component(v_wind)
• Dummy altitude for Zeb(alt)
• Surface dew point temperature(dp)
• base time(base_time)
• Relative humidity inside the instrument enclosure(rh)
• Retrieved pressure profile(pres)
• Wind Direction(deg)
• Wind Status(wstat)
• Dry bulb temperature(tdry)

• null(Raw data stream - documentation not supported)

SGP/SONDE/C1 - Questionable RH CF sounding 0211211:1130

The RH samples in this sounding oscillate between reasonable values (60-80%) and zero.  
This may be a problem with the RH sensor or the software that alternates between the heated 
and non-heated RH elements.  In either case, the reported values are questionable.  More 
investigation of the raw binary data would be required to diagnose further.

• Relative humidity inside the instrument enclosure(rh)
• Surface dew point temperature(dp)

• Surface dew point temperature(dp)
• Relative humidity inside the instrument enclosure(rh)

SGP/SONDE/C1 - Bad RH Data

The RH values during the first 15 minutes of this sounding oscillate between reasonable 
values and near-zero values.  The oscillation is irregular and seems to be related to 
failure of the RH sensor heating process.  I have informed Vaisala of the problem and provided 
raw data files to them for analysis.

• Relative humidity inside the instrument enclosure(rh)
• Surface dew point temperature(dp)

• Surface dew point temperature(dp)
• Relative humidity inside the instrument enclosure(rh)

SGP/SONDE/C1 - Broken temperature sensor SGP/CF sounding

The radiosonde temperature sensor apparently broke during launch.  This results in bad 
temperature, dew point, and rh data.

• Dry bulb temperature(tdry)
• Relative humidity inside the instrument enclosure(rh)
• Surface dew point temperature(dp)

• Surface dew point temperature(dp)
• Dry bulb temperature(tdry)
• Relative humidity inside the instrument enclosure(rh)

SGP/SONDE/C1 - Bad temperature/RH

The temperature sensor broke shortly after launch.  All temperature and RH-related data 
are incorrect.

• Dry bulb temperature(tdry)
• Relative humidity inside the instrument enclosure(rh)
• Surface dew point temperature(dp)

• Surface dew point temperature(dp)
• Dry bulb temperature(tdry)
• Relative humidity inside the instrument enclosure(rh)

SGP/MWR/C1 - Intermittent Negative Sky Brightness Temperatures

Several related and recurring problems with the SGP MWRs have been
reported dating back to 1999.  These problems were due to the
occurrence of blackbody signals (in counts) that were half of those
expected. The symptoms included noisy data (especially at Purcell),
spikes in the data (especially at Vici), negative brightness
temperatures, and apparent loss of serial communication between the
computer and the radiometer, which results in a self-termination of the
MWR program (especially at the CF).

Because these all initially appeared to be hardware-related problems,
the instrument mentor and SGP site operations personnel (1) repeatedly
cleaned and replaced the fiber optic comm. components, (2) swapped
radiometers, (3) sent radiometers back to Radiometrics for evaluation
(which has not revealed any instrument problems), and (4) reconfigured
the computer's operating system.  Despite several attempts to isolate
and correct it, the problem persisted.

It became apparent that some component of the Windows98 configuration
conflicted with the DOS-based MWR program or affected the serial port
or the contents of the serial port buffer. This problem was finally
corrected by upgrading the MWR software with a new Windows-compatible
program.

• Averaged total liquid water along LOS path(liq)
• Sky brightness temperature at 23.8 GHz(tbsky23)
• MWR column precipitable water vapor(vap)
• Sky brightness temperature at 31.4 GHz(tbsky31)

• Sky brightness temperature at 31.4 GHz(tbsky31)
• Averaged total liquid water along LOS path(liq)
• MWR column precipitable water vapor(vap)
• Sky brightness temperature at 23.8 GHz(tbsky23)

• Sky brightness temperature at 23.8 GHz(tbsky23)
• Averaged total liquid water along LOS path(liq)
• MWR column precipitable water vapor(vap)
• Sky brightness temperature at 31.4 GHz(tbsky31)

• MWR column precipitable water vapor(vap)
• Sky brightness temperature at 23.8 GHz(tbsky23)
• Sky brightness temperature at 31.4 GHz(tbsky31)
• Averaged total liquid water along LOS path(liq)

SGP/Sonde/C1 - Bad temperature, RH

These three soundings all show the effects of a temperature sensor broken at launch.  The 
temperature, RH, dew-point values all are incorrect.

• Dry bulb temperature(tdry)
• Relative humidity inside the instrument enclosure(rh)
• Surface dew point temperature(dp)

• Surface dew point temperature(dp)
• Dry bulb temperature(tdry)
• Relative humidity inside the instrument enclosure(rh)

SGP/Sonde/C1 - Bad RH in sounding

The RH sensor heating circuit was out of synch from about 400 sec after launch until the 
circuit was turned off whent he sounding temperature reached approximately 233 degK (-40 
degC) about 1500 sec after launch.  During this time period the reported RH oscillates 
between reasonable values and near-zero values.

• Relative humidity inside the instrument enclosure(rh)
• Surface dew point temperature(dp)

• Surface dew point temperature(dp)
• Relative humidity inside the instrument enclosure(rh)

SGP/Sonde/C1 - Sondes launched an hour early

It looks like someone forgot to set his/her clock ahead.  The sounding that should have 
been done at 23:30 UTC on 4/6 was done at 22:38 and the following sounding, which should 
have been done at 0530 on 4/7 was done at 04:31.  The subsequent soundings all are done at 
the correct times.

• null(Raw data stream - documentation not supported)

• Mean Wind Speed(wspd)
• Dummy altitude for Zeb(alt)
• V-component(v_wind)
• base time(base_time)
• Relative humidity inside the instrument enclosure(rh)
• Ascent Rate(asc)
• Wind Direction(deg)
• Wind Status(wstat)
• U-component(u_wind)
• Surface dew point temperature(dp)
• Dry bulb temperature(tdry)
• Time offset of tweaks from base_time(time_offset)
• lat(lat)
• lon(lon)
• Retrieved pressure profile(pres)

• Mean Wind Speed(wspd)
• U-component(u_wind)
• lat(lat)
• Ascent Rate(asc)
• lon(lon)
• Time offset of tweaks from base_time(time_offset)
• V-component(v_wind)
• Dummy altitude for Zeb(alt)
• Surface dew point temperature(dp)
• base time(base_time)
• Relative humidity inside the instrument enclosure(rh)
• Retrieved pressure profile(pres)
• Wind Direction(deg)
• Wind Status(wstat)
• Dry bulb temperature(tdry)

SGP/Sonde/C1 - Incorrect surface temperature on CF sounding

It appears that the operator entered an incorrect value for surface temperature.  Rather 
than 43.2 degC in the file, the value is most likely 19. degC (thwaps reading 19.4, first 
sonde reading aloft 18.6).

• Dry bulb temperature(tdry)

• Dry bulb temperature(tdry)

SGP/Sonde/C1 - Failed Sonde Launches due to Antenna problems

These sonde launches where unsuccessful due to problems
with the antenna configuration resulting in signal loss
before the launch.

• Mean Wind Speed(wspd)
• V-component(v_wind)
• Dummy altitude for Zeb(alt)
• base time(base_time)
• Relative humidity inside the instrument enclosure(rh)
• Ascent Rate(asc)
• U-component(u_wind)
• Wind Status(wstat)
• Wind Direction(deg)
• Surface dew point temperature(dp)
• Dry bulb temperature(tdry)
• Time offset of tweaks from base_time(time_offset)
• lat(lat)
• lon(lon)
• Retrieved pressure profile(pres)

• U-component(u_wind)
• Mean Wind Speed(wspd)
• lat(lat)
• Ascent Rate(asc)
• lon(lon)
• Time offset of tweaks from base_time(time_offset)
• V-component(v_wind)
• Dummy altitude for Zeb(alt)
• Surface dew point temperature(dp)
• base time(base_time)
• Relative humidity inside the instrument enclosure(rh)
• Retrieved pressure profile(pres)
• Wind Direction(deg)
• Wind Status(wstat)
• Dry bulb temperature(tdry)

• null(Raw data stream - documentation not supported)

• lon(lon)
• Dummy altitude for Zeb(alt)
• base time(base_time)
• Retrieved pressure profile(pres)
• Relative humidity inside the instrument enclosure(rh)
• Dry bulb temperature(tdry)
• lat(lat)
• Time offset of tweaks from base_time(time_offset)

SGP/SONDE/C1 - Broken Temperature Sensor

The temperature sensor broke shortly after launch as a result all variables that are 
affected by temperature are incorrect.

• Dry bulb temperature(tdry)
• Relative humidity inside the instrument enclosure(rh)
• Surface dew point temperature(dp)

• Surface dew point temperature(dp)
• Dry bulb temperature(tdry)
• Relative humidity inside the instrument enclosure(rh)

SGP/SONDE/C1 - Broken temperature sensor

The temperature sensor on this radiosonde broke after launch.  All temperature-related 
variables (dp, tdry, rh) are incorrect.

• Dry bulb temperature(tdry)
• Relative humidity inside the instrument enclosure(rh)
• Surface dew point temperature(dp)

• Surface dew point temperature(dp)
• Dry bulb temperature(tdry)
• Relative humidity inside the instrument enclosure(rh)

SGP/SONDE/C1 - Broken temperature sensors

The temperature sensors broke at launch on both of these soundings.  All of the 
temperature-related data (tdry, rh, dp) are incorrect.

• Dry bulb temperature(tdry)
• Relative humidity inside the instrument enclosure(rh)
• Surface dew point temperature(dp)

• Surface dew point temperature(dp)
• Dry bulb temperature(tdry)
• Relative humidity inside the instrument enclosure(rh)

SGP/SONDE/C1 - Broken temperature sensor

The temperature sensor broke at launch on this sounding.  All of the temperature-related 
data (tdry, rh, dp) are incorrect.

• Dry bulb temperature(tdry)
• Relative humidity inside the instrument enclosure(rh)
• Surface dew point temperature(dp)

• Surface dew point temperature(dp)
• Dry bulb temperature(tdry)
• Relative humidity inside the instrument enclosure(rh)

SGP/SONDE/C1 - Incorrect surface RH value.

The surface RH value, reported as 0%RH should be 52%.  This resulted from a typographical 
error by the operator when entering the surface data.

• Relative humidity inside the instrument enclosure(rh)
• Surface dew point temperature(dp)

• Surface dew point temperature(dp)
• Relative humidity inside the instrument enclosure(rh)

SGP/SONDE/C1 - Broken temperature sensor

The temperature sensor broke at launch on this sounding.  All of the temperature-related 
data (tdry, rh, dp) are incorrect.

• Dry bulb temperature(tdry)
• Relative humidity inside the instrument enclosure(rh)
• Surface dew point temperature(dp)

• Surface dew point temperature(dp)
• Dry bulb temperature(tdry)
• Relative humidity inside the instrument enclosure(rh)

SGP/SONDE/C1 - A few bad temperature values at the beginning of the sounding

I've never seen this before.  The temperature reported by the radiosonde dropped over 30 
degC just after launch (usually a symptom of a broken temperature sensor), but then 
recovered after 14 seconds of bad readings.  The temperatures from 2 seconds through 14 seconds 
after launch are incorrect, the remainder of the sounding looks fine.  I have sent the 
data files to Vaisala for their consideration.

• Dry bulb temperature(tdry)
• Surface dew point temperature(dp)

• Surface dew point temperature(dp)
• Dry bulb temperature(tdry)

SGP/SONDE/C1 - Broken temperature sensor

The temperature sensor broke at launch on this sounding.  All of the temperature-related 
data (tdry, rh, dp) are incorrect.

• Surface dew point temperature(dp)
• Dry bulb temperature(tdry)
• Relative humidity inside the instrument enclosure(rh)

SGP/SONDE/C1 - Bad RH Data

The RH values during the first half of this sounding oscillate between reasonable values 
and near-zero values.  The oscillation is irregular and seems to be related to failure of 
the RH sensor heating process.

• Surface dew point temperature(dp)
• Relative humidity inside the instrument enclosure(rh)

SGP/SONDE/C1 - Bad RH Data

The RH values during the first part of this sounding oscillate between reasonable values 
and near-zero values.  The oscillation seems to be related to failure of the RH sensor 
heating process.

• Surface dew point temperature(dp)
• Relative humidity inside the instrument enclosure(rh)

SGP/SONDE/C1 - Surface pressure incorrect

I think the operator inadvdertently transposed to digits when entering the surface 
pressure value.  The value entered is 987.0 hPa but the value shown in the raw data file at 
launch is 978.0.  As a result, the absolute altitudes in this sounding will be slightly 
incorrect as will be the ascent rate during the first 30 seconds of flight.

• Ascent Rate(asc)
• Dummy altitude for Zeb(alt)

SGP/SONDE/C1 - Broken temperature sensor

The temperature sensor broke at launch on this sounding.  All of the temperature-related 
data (tdry, rh, dp) are incorrect.

• Surface dew point temperature(dp)
• Dry bulb temperature(tdry)
• Relative humidity inside the instrument enclosure(rh)

SGP/SONDE/C1 - Broken temperature sensor

The temperature sensor broke shortly after launch on this sounding.  All of the 
temperature-related data (tdry, rh, dp) are incorrect.

• Surface dew point temperature(dp)
• Dry bulb temperature(tdry)
• Relative humidity inside the instrument enclosure(rh)

SGP/SONDE/C1 - Temperature sensor broke high into the sounding

The temperature sensor on this radiosonde appeared to break 56 minutes and 22 seconds into 
the sounding at an altitude of 16570 m.  All the data below this point are good; only 
the data above this point to the end of the sounding (88 minutes and 14 seconds) are bad.

• Surface dew point temperature(dp)
• Dry bulb temperature(tdry)
• Relative humidity inside the instrument enclosure(rh)

SGP/MWR/B1 - Loss of thermal stabilization

Periodically during August and September 1995 all microwave radiometers
at the SGP CART generated error messages in the Site Operations Log
like:

  Time: Sat Aug 19 18:41:20 1995
  MWRLOS.C1, tkxc: Value above Maximum.

This indicates that the temperature of the microwave hardware
(specifically, the cross-coupler or "xc") exceeded its controlled
temperature (47-52 deg C) at which point it was no longer thermally
stabilized and the gain was uncontrolled.  During these periods which
typically last about 8 hours from about local noon until about sunset
the data behave anomalously and should be considered invalid.

Specifically the precipitable water vapor increases and the liquid
water path decreases (and becomes SIGNIFICANTLY NEGATIVE (-0.1 mm) on
clear sky days).  The RMS noise level in the data also increases
sharply.  The 'Tkxc' field appears ONLY in the a0-level data and does
NOT appear in either the a1 (mwrlos) or c1 (mwr5avg) files.  Therefore
THESE ANOMALOUS VALUES HAVE BEEN INCLUDED IN THE 5-MINUTE AVERAGES.

The microwave hardware is thermally stabilized to about +/- 0.1 deg C
by resistive heating.  When the internal temperature rises above the
set point the thermal stabilization of the instrument gain is lost.
>From an examination of the component temperature data it appears that
increasing the set point temperature to about 55 deg C (328 K) would
prevent a re-ocurrance of this problem at the SGP.  The manufacturer,
Radiometrics, concurs that raising the set point will fix this problem
and will not cause other problems.

I will have to carefully examine the MCTEX data to determine whether
this will be a problem for the TWP.  The manufacturer and I had
discussed this possibility prior to building the TWP MWRs (S/N 015,
016, and 017) and those instruments have set points above 50 deg C.
Note that MWR 018 has a set point near 52 deg C (like the TWP models)
but it still experienced a few loss-of-stabilization events.

Note that the instruments with the lowest set points had the most
loss-of-stabilization events.

• 23.8 GHz sky brightness temperature(23tbsky)
• MWR column precipitable water vapor(vap)
• Averaged total liquid water along LOS path(liq)
• 31.4 GHz sky brightness temperature(31tbsky)

• 31.4 GHz sky brightness temperature(31tbsky)
• MWR column precipitable water vapor(vap)
• 23.8 GHz sky brightness temperature(23tbsky)
• Averaged total liquid water along LOS path(liq)

• 31.4 GHz sky brightness temperature(31tbsky)
• MWR column precipitable water vapor(vap)
• Averaged total liquid water along LOS path(liq)
• 23.8 GHz sky brightness temperature(23tbsky)

SGP/MWR/B5 - Loss of thermal stabilization

Periodically during August and September 1995 all microwave radiometers
at the SGP CART generated error messages in the Site Operations Log
like:

  Time: Sat Aug 19 18:41:20 1995
  MWRLOS.C1, tkxc: Value above Maximum.

This indicates that the temperature of the microwave hardware
(specifically, the cross-coupler or "xc") exceeded its controlled
temperature (47-52 deg C) at which point it was no longer thermally
stabilized and the gain was uncontrolled.  During these periods which
typically last about 8 hours from about local noon until about sunset
the data behave anomalously and should be considered invalid.

Specifically the precipitable water vapor increases and the liquid
water path decreases (and becomes SIGNIFICANTLY NEGATIVE (-0.1 mm) on
clear sky days).  The RMS noise level in the data also increases
sharply.  The 'Tkxc' field appears ONLY in the a0-level data and does
NOT appear in either the a1 (mwrlos) or c1 (mwr5avg) files.  Therefore
THESE ANOMALOUS VALUES HAVE BEEN INCLUDED IN THE 5-MINUTE AVERAGES.

The microwave hardware is thermally stabilized to about +/- 0.1 deg C
by resistive heating.  When the internal temperature rises above the
set point the thermal stabilization of the instrument gain is lost.
>From an examination of the component temperature data it appears that
increasing the set point temperature to about 55 deg C (328 K) would
prevent a re-ocurrance of this problem at the SGP.  The manufacturer,
Radiometrics, concurs that raising the set point will fix this problem
and will not cause other problems.

I will have to carefully examine the MCTEX data to determine whether
this will be a problem for the TWP.  The manufacturer and I had
discussed this possibility prior to building the TWP MWRs (S/N 015,
016, and 017) and those instruments have set points above 50 deg C.
Note that MWR 018 has a set point near 52 deg C (like the TWP models)
but it still experienced a few loss-of-stabilization events.

Note that the instruments with the lowest set points had the most
loss-of-stabilization events.

• 31.4 GHz sky brightness temperature(31tbsky)
• 23.8 GHz sky brightness temperature(23tbsky)
• MWR column precipitable water vapor(vap)
• Averaged total liquid water along LOS path(liq)

• MWR column precipitable water vapor(vap)
• Averaged total liquid water along LOS path(liq)
• 23.8 GHz sky brightness temperature(23tbsky)
• 31.4 GHz sky brightness temperature(31tbsky)

• Averaged total liquid water along LOS path(liq)
• MWR column precipitable water vapor(vap)
• 31.4 GHz sky brightness temperature(31tbsky)
• 23.8 GHz sky brightness temperature(23tbsky)

SGP/MWR/B6 - Loss of thermal stabilization

Periodically during August and September 1995 all microwave radiometers
at the SGP CART generated error messages in the Site Operations Log
like:

  Time: Sat Aug 19 18:41:20 1995
  MWRLOS.C1, tkxc: Value above Maximum.

This indicates that the temperature of the microwave hardware
(specifically, the cross-coupler or "xc") exceeded its controlled
temperature (47-52 deg C) at which point it was no longer thermally
stabilized and the gain was uncontrolled.  During these periods which
typically last about 8 hours from about local noon until about sunset
the data behave anomalously and should be considered invalid.

Specifically the precipitable water vapor increases and the liquid
water path decreases (and becomes SIGNIFICANTLY NEGATIVE (-0.1 mm) on
clear sky days).  The RMS noise level in the data also increases
sharply.  The 'Tkxc' field appears ONLY in the a0-level data and does
NOT appear in either the a1 (mwrlos) or c1 (mwr5avg) files.  Therefore
THESE ANOMALOUS VALUES HAVE BEEN INCLUDED IN THE 5-MINUTE AVERAGES.

The microwave hardware is thermally stabilized to about +/- 0.1 deg C
by resistive heating.  When the internal temperature rises above the
set point the thermal stabilization of the instrument gain is lost.
>From an examination of the component temperature data it appears that
increasing the set point temperature to about 55 deg C (328 K) would
prevent a re-ocurrance of this problem at the SGP.  The manufacturer,
Radiometrics, concurs that raising the set point will fix this problem
and will not cause other problems.

I will have to carefully examine the MCTEX data to determine whether
this will be a problem for the TWP.  The manufacturer and I had
discussed this possibility prior to building the TWP MWRs (S/N 015,
016, and 017) and those instruments have set points above 50 deg C.
Note that MWR 018 has a set point near 52 deg C (like the TWP models)
but it still experienced a few loss-of-stabilization events.

Note that the instruments with the lowest set points had the most
loss-of-stabilization events.

• MWR column precipitable water vapor(vap)
• 23.8 GHz sky brightness temperature(23tbsky)
• Averaged total liquid water along LOS path(liq)
• 31.4 GHz sky brightness temperature(31tbsky)

• 31.4 GHz sky brightness temperature(31tbsky)
• Averaged total liquid water along LOS path(liq)
• MWR column precipitable water vapor(vap)
• 23.8 GHz sky brightness temperature(23tbsky)

• Averaged total liquid water along LOS path(liq)
• MWR column precipitable water vapor(vap)
• 31.4 GHz sky brightness temperature(31tbsky)
• 23.8 GHz sky brightness temperature(23tbsky)

SGP/SONDE/C1 - Incorrect surface temperature

The operator entered a the surface temperature incorrectly on this sounding.  The sonde 
data file shows the temperature as 33.5 degC but the operations log shows it as 3.5 degC.  
The first temperature recorded by the sonde after launch is 3.7 degC, consistent with the 
typical early morning inversion.

• Surface dew point temperature(dp)
• Dry bulb temperature(tdry)
• Relative humidity inside the instrument enclosure(rh)

SGP/SONDE/C1 - Scheduled Soundings Missed

The following scheduled sonde launches were missed due to computer 
system failures:

20040116.2330
20040117.0530
20040117.1130
20040117.1730
20040118.0530
20040121.0530

• Surface dew point temperature(dp)
• base time(base_time)
• Mean Wind Speed(wspd)
• U-component(u_wind)
• Relative humidity inside the instrument enclosure(rh)
• lat(lat)
• Ascent Rate(asc)
• Retrieved pressure profile(pres)
• Wind Direction(deg)
• Wind Status(wstat)
• lon(lon)
• Dry bulb temperature(tdry)
• Time offset of tweaks from base_time(time_offset)
• V-component(v_wind)
• Dummy altitude for Zeb(alt)

• null(Raw data stream - documentation not supported)

SGP/SONDE/C1 - Possibly bad pressure sensor or operator data entry error

There is a discrepency between the surface pressure and temperature data entered by the 
operator and that recorded by the THWAPS.  Review of the raw data from the radiosonde shows 
that the pressure was periodically varying by as much as 12 hPa (~988 to 1000)in the 
time period before launch.  The operator entry of 998.2 is at the high end of this range - 
the concurrent THWAPS reading was about 988.4 at the low end.  The operator entered 
temperature 6.2 degC is considerably higher than the THWAPS value of 1.8.  The pre-flight log 
entry for this sounding is missing from the OMIS database.  If not for the extremely 
unstable pressure reading I would have assumed this was an operator error.  It will take some 
more research to figure out what is going on.

• Surface dew point temperature(dp)
• base time(base_time)
• Mean Wind Speed(wspd)
• U-component(u_wind)
• Relative humidity inside the instrument enclosure(rh)
• lat(lat)
• Ascent Rate(asc)
• Retrieved pressure profile(pres)
• Wind Direction(deg)
• Wind Status(wstat)
• lon(lon)
• Dry bulb temperature(tdry)
• Time offset of tweaks from base_time(time_offset)
• V-component(v_wind)
• Dummy altitude for Zeb(alt)

SGP/SONDE/C1 - Surface pressure incorrect

I think the operator inadvdertently entered an incorrect surface pressure value.  The 
value entered is 988.8 hPa but the value shown in the raw data file at launch is 968.8.  As a 
result, the absolute altitudes in this sounding will be slightly incorrect as will be 
the ascent rate during the first 30 seconds of flight.

• Ascent Rate(asc)
• Dummy altitude for Zeb(alt)

SGP/SONDE/C1 - Surface pressure bad and other data noisy

I was checking this sounding because the surface pressure entered by the operator was 
considerably higher than that recorded by the TWHAPS and SMOS.  I'm not sure why, but the 
pressure data are very noisy while the sonde is on the ground (which accounts for the 
incorrect surface pressure) and the RH data aloft do not look terrible but do not look great 
either.

• Surface dew point temperature(dp)
• base time(base_time)
• Mean Wind Speed(wspd)
• U-component(u_wind)
• Relative humidity inside the instrument enclosure(rh)
• lat(lat)
• Ascent Rate(asc)
• Retrieved pressure profile(pres)
• Wind Direction(deg)
• Wind Status(wstat)
• lon(lon)
• Dry bulb temperature(tdry)
• Time offset of tweaks from base_time(time_offset)
• V-component(v_wind)
• Dummy altitude for Zeb(alt)

SGP/SONDE/C1 - Surface pressure incorrect

I think the operator inadvdertently typed an 89 instead of a 78 when entering the surface 
pressure value.  The value entered is 989.9 hPa but the value shown in the raw data file 
at launch is 978.9.  As a result, the absolute altitudes in this sounding will be 
slightly incorrect as will be the ascent rate during the first 30 seconds of flight.

• Ascent Rate(asc)
• Dummy altitude for Zeb(alt)

SGP/SONDE/C1 - Surface pressure incorrect

I think the operator inadvdertently mistyped a digit when entering the surface pressure 
value.  The value entered is 975.6 hPa but the value shown in the raw data file at launch 
is 972.6.  As a result, the absolute altitudes in this sounding will be slightly incorrect 
as will be the ascent rate during the first 30 seconds of flight.

• Ascent Rate(asc)
• Dummy altitude for Zeb(alt)

SGP/MWR/C1 - REPROCESS - Revised Retrieval Coefficients

IN THE BEGINNING (June 1992), the retrieval coefficients used to derive the precipitable 
water vapor (PWV) and liquid water path (LWP) from the MWR brightness temperatures were 
based on the Liebe and Layton (1987) water vapor and oxygen absorption model and the Grant 
(1957) liquid water absorption model.  

Following the SHEBA experience, revised retrievals based on the more recent Rosenkranz 
(1998) water vapor and oxygen absorption models and the Liebe (1991) liquid waer absorption 
model were developed.  The Rosenkranz water vapor absorption model resulted a 2 percent 
increase in PWV relative to the earlier Liebe and Layton model.  The Liebe liquid water 
absorption model decreased the LWP by 10% relative to the Grant model.  However, the 
increased oxygen absorption caused a 0.02-0.03 mm (20-30 g/m2) reduction in LWP, which was 
particularly significant for low LWP conditions (i.e. thin clouds encountered at SHEBA).

Recently, it has been shown (Liljegren, Boukabara, Cady-Pereira, and Clough, TGARS v. 43, 
pp 1102-1108, 2005) that the half-width of the 22 GHz water vapor line from the HITRAN 
compilation, which is 5 percent smaller than the Liebe and Dillon (1969) half-width used in 
Rosenkranz (1998), provided a better fit to the microwave brightness temperature 
measurements at 5 frequencies in the range 22-30 GHz, and yielded more accurate retrievals.  
Accordingly, revised MWR retrieval coefficients have been developed using MONORTM, which 
utilizes the HITRAN compilation for its spectroscopic parameters.  These new retrievals 
provide 3 percent less PWV and 2.6 percent greater LWP than the previous retrievals based on 
Rosenkranz (1998).

Although the MWR data will be reprocessed to apply the new monortm-based retrievals, for 
most purposes it will be sufficient to correct the data using the following factors:

PWV_MONORTM = 0.9695 * PWV_ROSENKRANZ
LWP_MONORTM = 1.026  * LWP_ROSENKRANZ

The Rosenkranz-based retrieval coefficients became active as follows (BCR 456):
SGP/C1 (Lamont)     4/16/2002, 2000
SGP/B1 (Hillsboro)  4/12/2002, 1600
SGP/B4 (Vici)       4/15/2002, 2300
SGP/B5 (Morris)     4/15/2002, 2300
SGP/B6 (Purcell)    4/16/2002, 2200
SGP/E14(Lamont)     4/16/2002, 0000
NSA/C1 (Barrow)     4/25/2002, 1900 
NSA/C2 (Atqasuk)    4/18/2002, 1700
TWP/C1 (Manus)      5/04/2002, 0200
TWP/C2 (Nauru)      4/27/2002, 0600
TWP/C3 (Darwin)     inception

The MONORTM-based retrieval coefficients became active as follows (BCR 984):

SGP/C1 (Lamont)     6/28/2005, 2300
SGP/B1 (Hillsboro)  6/24/2005, 2100
SGP/B4 (Vici)       6/24/2005, 2100
SGP/B5 (Morris)     6/24/2005, 2100
SGP/B6 (Purcell)    6/24/2005, 1942
SGP/E14(Lamont)     6/28/2005, 2300
NSA/C1 (Barrow)     6/29/2005, 0000 
NSA/C2 (Atqasuk)    6/29/2005, 0000
TWP/C1 (Manus)      6/30/2005, 2100
TWP/C2 (Nauru)      6/30/2005, 2100
TWP/C3 (Darwin)     6/30/2005, 2100
PYE/M1 (Pt. Reyes)  4/08/2005, 1900**

** At Pt. Reyes, the original retrieval coefficients implemented in March 2005 were based 
on a version of the Rosenkranz model that had been modified to use the HITRAN half-width 
at 22 GHz and to be consistent with the water vapor continuum in MONORTM.  These 
retrievals yield nearly identical results to the MONORTM retrievals.  Therefore the Pt. Reyes 
data prior to 4/08/2005 may not require reprocessing.

• Total liquid water along zenith path using tip-derived brightness temperatures(liqtip)
• Total water vapor along zenith path using tip-derived brightness temperatures(vaptip)

• MWR column precipitable water vapor(vap)
• Averaged total liquid water along LOS path(liq)

• MWR column precipitable water vapor(vap)
• Averaged total liquid water along LOS path(liq)

• Averaged total liquid water along LOS path(liq)
• MWR column precipitable water vapor(vap)

• Ensemble average for MWR vapor in window centered about balloon release(mean_vap_mwr)
• Ensemble average for MWR liquid in window centered about balloon release(mean_liq_mwr)

• Averaged total liquid water along LOS path(liq)
• MWR column precipitable water vapor(vap)

SGP/SONDE/C1 - Bad RH Data

The RH values below 6 km are incorrect.  The problem relates to a failure of the GC25 
ground check set used before this particular sounding.  The failure seems to have affected 
the sensor calibration with the effect that one of the two sensors was reading artificially 
high.  Because the internal processing software uses the highest of the two sensor 
readings, the bad sensor value is chosen whenever it is not heated.

• Surface dew point temperature(dp)
• Relative humidity inside the instrument enclosure(rh)

SGP/MWR/B1 - Reprocess: Revised Retrieval Coefficients

IN THE BEGINNING (June 1992), the retrieval coefficients used to derive the precipitable 
water vapor (PWV) and liquid water path (LWP) from the MWR brightness temperatures were 
based on the Liebe and Layton (1987) water vapor and oxygen absorption model and the Grant 
(1957) liquid water absorption model.

Following the SHEBA experience, revised retrievals based on the more recent Rosenkranz 
(1998) water vapor and oxygen absorption models and the Liebe (1991) liquid waer absorption 
model were developed.  The Rosenkranz water vapor absorption model resulted a 2 percent 
increase in PWV relative to the earlier Liebe and Layton model.  The Liebe liquid water 
absorption model decreased the LWP by 10% relative to the Grant model.  However, the 
increased oxygen absorption caused a 0.02-0.03 mm (20-30 g/m2) reduction in LWP, which was 
particularly significant for low LWP conditions (i.e. thin clouds encountered at SHEBA).

Recently, it has been shown (Liljegren, Boukabara, Cady-Pereira, and Clough, TGARS v. 43, 
pp 1102-1108, 2005) that the half-width of the 22 GHz water vapor line from the HITRAN 
compilation, which is 5 percent smaller than the Liebe and Dillon (1969) half-width used in 
Rosenkranz (1998), provided a better fit to the microwave brightness temperature 
measurements at 5 frequencies in the range 22-30 GHz, and yielded more accurate retrievals. 
Accordingly, revised MWR retrieval coefficients have been developed using MONORTM, which 
utilizes the HITRAN compilation for its spectroscopic parameters.  These new retrievals 
provide 3 percent less PWV and 2.6 percent greater LWP than the previous retrievals based on 
Rosenkranz (1998).

Although the MWR data will be reprocessed to apply the new monortm-based retrievals, for 
most purposes it will be sufficient to correct the data using the following factors:

PWV_MONORTM = 0.9695 * PWV_ROSENKRANZ
LWP_MONORTM = 1.026  * LWP_ROSENKRANZ

The Rosenkranz-based retrieval coefficients became active at SGP.B1 20020412.1600.  The 
MONORTM-based retrieval coefficients became active at SGP.B1 20050624.2100.

Note: a reprocessing effort is already underway to apply the Rosenkranz-based retrieval 
coefficients to all MWR prior to April 2002.  An additional reprocessing task will be 
undertaken to apply the MONORTM retrieval to all MWR data when the first is completed.  Read 
reprocessing comments in the netcdf file header carefully to ensure you are aware which 
retrieval is in play.

• MWR column precipitable water vapor(vap)
• Averaged total liquid water along LOS path(liq)

• Averaged total liquid water along LOS path(liq)
• MWR column precipitable water vapor(vap)

• MWR column precipitable water vapor(vap)
• Averaged total liquid water along LOS path(liq)

• Total liquid water along zenith path using tip-derived brightness temperatures(liqtip)
• Total water vapor along zenith path using tip-derived brightness temperatures(vaptip)

• Ensemble average for MWR liquid in window centered about balloon release(mean_liq_mwr)
• Ensemble average for MWR vapor in window centered about balloon release(mean_vap_mwr)

SGP/MWR/B4 - Reprocess: Revised Retrieval Coefficients

IN THE BEGINNING (June 1992), the retrieval coefficients used to derive the precipitable 
water vapor (PWV) and liquid water path (LWP) from the MWR brightness temperatures were 
based on the Liebe and Layton (1987) water vapor and oxygen absorption model and the Grant 
(1957) liquid water absorption model.

Following the SHEBA experience, revised retrievals based on the more recent Rosenkranz 
(1998) water vapor and oxygen absorption models and the Liebe (1991) liquid waer absorption 
model were developed.  The Rosenkranz water vapor absorption model resulted a 2 percent 
increase in PWV relative to the earlier Liebe and Layton model.  The Liebe liquid water 
absorption model decreased the LWP by 10% relative to the Grant model.  However, the 
increased oxygen absorption caused a 0.02-0.03 mm (20-30 g/m2) reduction in LWP, which was 
particularly significant for low LWP conditions (i.e. thin clouds encountered at SHEBA).

Recently, it has been shown (Liljegren, Boukabara, Cady-Pereira, and Clough, TGARS v. 43, 
pp 1102-1108, 2005) that the half-width of the 22 GHz water vapor line from the HITRAN 
compilation, which is 5 percent smaller than the Liebe and Dillon (1969) half-width used in 
Rosenkranz (1998), provided a better fit to the microwave brightness temperature 
measurements at 5 frequencies in the range 22-30 GHz, and yielded more accurate retrievals. 
Accordingly, revised MWR retrieval coefficients have been developed using MONORTM, which 
utilizes the HITRAN compilation for its spectroscopic parameters.  These new retrievals 
provide 3 percent less PWV and 2.6 percent greater LWP than the previous retrievals based on 
Rosenkranz (1998).

Although the MWR data will be reprocessed to apply the new monortm-based retrievals, for 
most purposes it will be sufficient to correct the data using the following factors:

PWV_MONORTM = 0.9695 * PWV_ROSENKRANZ
LWP_MONORTM = 1.026  * LWP_ROSENKRANZ

The Rosenkranz-based retrieval coefficients became active at SGP.B4 20020415.2300.  The 
MONORTM-based retrieval coefficients became active at SGP.B4 20050624.2100.

Note: a reprocessing effort is already underway to apply the Rosenkranz-based retrieval 
coefficients to all MWR prior to April 2002.  An additional reprocessing task will be 
undertaken to apply the MONORTM retrieval to all MWR data when the first is completed. Read 
reprocessing comments in the netcdf file header carefully to ensure you are aware which 
retrieval is in play.

• Averaged total liquid water along LOS path(liq)
• MWR column precipitable water vapor(vap)

• Total water vapor along zenith path using tip-derived brightness temperatures(vaptip)
• Total liquid water along zenith path using tip-derived brightness temperatures(liqtip)

• Ensemble average for MWR vapor in window centered about balloon release(mean_vap_mwr)
• Ensemble average for MWR liquid in window centered about balloon release(mean_liq_mwr)

• Averaged total liquid water along LOS path(liq)
• MWR column precipitable water vapor(vap)

• MWR column precipitable water vapor(vap)
• Averaged total liquid water along LOS path(liq)

SGP/MWR/B5 - Reprocess: Revised Retrieval Coefficients

IN THE BEGINNING (June 1992), the retrieval coefficients used to derive 
the precipitable water vapor (PWV) and liquid water path (LWP) from the 
MWR brightness temperatures were based on the Liebe and Layton (1987) 
water vapor and oxygen absorption model and the Grant (1957) liquid 
water absorption model.

Following the SHEBA experience, revised retrievals based on the more 
recent Rosenkranz (1998) water vapor and oxygen absorption models and 
the Liebe (1991) liquid waer absorption model were developed.  The 
Rosenkranz water vapor absorption model resulted a 2 percent increase 
in PWV relative to the earlier Liebe and Layton model.  The Liebe 
liquid water absorption model decreased the LWP by 10% relative to the 
Grant model.  However, the increased oxygen absorption caused a 
0.02-0.03 mm (20-30 g/m2) reduction in LWP, which was particularly 
significant for low LWP conditions (i.e. thin clouds encountered at 
SHEBA).

Recently, it has been shown (Liljegren, Boukabara, Cady-Pereira, and 
Clough, TGARS v. 43, pp 1102-1108, 2005) that the half-width of the 
22 GHz water vapor line from the HITRAN compilation, which is 5 percent 
smaller than the Liebe and Dillon (1969) half-width used in Rosenkranz 
(1998), provided a better fit to the microwave brightness temperature 
measurements at 5 frequencies in the range 22-30 GHz, and yielded more 
accurate retrievals. Accordingly, revised MWR retrieval coefficients 
have been developed using MONORTM, which utilizes the HITRAN compilation 
for its spectroscopic parameters.  These new retrievals provide 3 
percent less PWV and 2.6 percent greater LWP than the previous 
retrievals based on Rosenkranz (1998).

Although the MWR data will be reprocessed to apply the new monortm-based 
retrievals, for most purposes it will be sufficient to correct the data 
using the following factors:

PWV_MONORTM = 0.9695 * PWV_ROSENKRANZ
LWP_MONORTM = 1.026  * LWP_ROSENKRANZ

The Rosenkranz-based retrieval coefficients became active at SGP.B5 
20020415.2300.  The MONORTM-based retrieval coefficients became active 
at SGP.B5 20050624.2100.

Note: a reprocessing effort is already underway to apply the 
Rosenkranz-based retrieval coefficients to all MWR prior to April 
2002.  An additional reprocessing task will be undertaken to apply 
the MONORTM retrieval to all MWR data when the first is completed. 
Read reprocessing comments in the netcdf file header carefully to 
ensure you are aware which retrieval is in play.

• MWR column precipitable water vapor(vap)
• Averaged total liquid water along LOS path(liq)

• Total liquid water along zenith path using tip-derived brightness temperatures(liqtip)
• Total water vapor along zenith path using tip-derived brightness temperatures(vaptip)

• Ensemble average for MWR vapor in window centered about balloon release(mean_vap_mwr)
• Ensemble average for MWR liquid in window centered about balloon release(mean_liq_mwr)

• MWR column precipitable water vapor(vap)
• Averaged total liquid water along LOS path(liq)

• Averaged total liquid water along LOS path(liq)
• MWR column precipitable water vapor(vap)

SGP/MWR/B6 - Reprocess: Revised Retrieval Coefficients

IN THE BEGINNING (June 1992), the retrieval coefficients used to derive 
the precipitable water vapor (PWV) and liquid water path (LWP) from the 
MWR brightness temperatures were based on the Liebe and Layton (1987) 
water vapor and oxygen absorption model and the Grant (1957) liquid 
water absorption model.

Following the SHEBA experience, revised retrievals based on the more 
recent Rosenkranz (1998) water vapor and oxygen absorption models and 
the Liebe (1991) liquid waer absorption model were developed.  The 
Rosenkranz water vapor absorption model resulted a 2 percent increase 
in PWV relative to the earlier Liebe and Layton model.  The Liebe 
liquid water absorption model decreased the LWP by 10% relative to the 
Grant model.  However, the increased oxygen absorption caused a 
0.02-0.03 mm (20-30 g/m2) reduction in LWP, which was particularly 
significant for low LWP conditions (i.e. thin clouds encountered at 
SHEBA).

Recently, it has been shown (Liljegren, Boukabara, Cady-Pereira, and 
Clough, TGARS v. 43, pp 1102-1108, 2005) that the half-width of the 
22 GHz water vapor line from the HITRAN compilation, which is 5 percent 
smaller than the Liebe and Dillon (1969) half-width used in Rosenkranz 
(1998), provided a better fit to the microwave brightness temperature 
measurements at 5 frequencies in the range 22-30 GHz, and yielded more 
accurate retrievals. Accordingly, revised MWR retrieval coefficients 
have been developed using MONORTM, which utilizes the HITRAN compilation 
for its spectroscopic parameters.  These new retrievals provide 3 
percent less PWV and 2.6 percent greater LWP than the previous 
retrievals based on Rosenkranz (1998).

Although the MWR data will be reprocessed to apply the new monortm-based 
retrievals, for most purposes it will be sufficient to correct the data 
using the following factors:

PWV_MONORTM = 0.9695 * PWV_ROSENKRANZ
LWP_MONORTM = 1.026  * LWP_ROSENKRANZ

The Rosenkranz-based retrieval coefficients became active at SGP.B6 
20020416.2200.  The MONORTM-based retrieval coefficients became active 
at SGP.B6 20050624.1942.

Note: a reprocessing effort is already underway to apply the 
Rosenkranz-based retrieval coefficients to all MWR prior to April 
2002.  An additional reprocessing task will be undertaken to apply 
the MONORTM retrieval to all MWR data when the first is completed. 
Read reprocessing comments in the netcdf file header carefully to 
ensure you are aware which retrieval is in play.

• Total liquid water along zenith path using tip-derived brightness temperatures(liqtip)
• Total water vapor along zenith path using tip-derived brightness temperatures(vaptip)

• Averaged total liquid water along LOS path(liq)
• MWR column precipitable water vapor(vap)

• MWR column precipitable water vapor(vap)
• Averaged total liquid water along LOS path(liq)

• Ensemble average for MWR liquid in window centered about balloon release(mean_liq_mwr)
• Ensemble average for MWR vapor in window centered about balloon release(mean_vap_mwr)

• Averaged total liquid water along LOS path(liq)
• MWR column precipitable water vapor(vap)

SGP/SONDE/C1 - Bad T/RH and surface P.

Apparently multiple failures.  The radiosonde temperature sensor broke on launch causing 
an approximate 35 degC negative offset and as a result, the RH is incorrect.  Furthermore, 
it appears that the pressure sensor was off by approximately 4 hPa, though this would 
not affect the altitude calculation, the absolute pressure is wrong.

• Dry bulb temperature(tdry)
• Relative humidity inside the instrument enclosure(rh)
• Retrieved pressure profile(pres)

SGP/SONDE/C1 - Temperature/RH incorrect

The temperature throughout this sounding is too high and as a result the RH values will be 
incorrect as well.  I'm not sure what is wrong here but the operators noted reasonable 
values (18.1 degC, 87%) in the log before launch.  Review of the raw data, however, shows 
the sonde reporting temperatures nearly 20 degC higher.  I suppose it is possible that 
the operator entered into the log the reference temperature from the GC25 ground check set 
rather than the temperature reported by the sonde - I can't think of any other 
explanation - there is no doubt that the temperature sensor on this sonde was bad.

• Surface dew point temperature(dp)
• Dry bulb temperature(tdry)
• Relative humidity inside the instrument enclosure(rh)

• Relative humidity inside the instrument enclosure(rh)
• Dry bulb temperature(tdry)

SGP/MWR/C1 - Instrument noise problem

Various variables including the mixer temperatures were very noisy. After several attempts 
to fix the problem, the instrument was taken off line and returned to the manufacturer 
for repair.

• 31.4 GHz blac2body+noise injection signal(bbn31)
• 31.4 GHz blackbody(bb31)
• Noise injection temp at 23.8 GHz adjusted to tkbb(tnd23)
• (tknd)
• Water on Teflon window (1=WET, 0=DRY)(wet_window)
• Total liquid water along zenith path using tip-derived brightness temperatures(liqtip)
• Noise injection temp at 31.4 GHz adjusted to tkbb(tnd31)
• Blackbody kinetic temperature(tkbb)
• 23.8 GHz Blackbody signal(bb23)
• Temperature correction coefficient at 23.8 GHz(tc23)
• Ambient temperature(tkair)
• Mixer kinetic (physical) temperature(tkxc)
• 23.8 GHz blackbody+noise injection signal(bbn23)
• Noise injection temp at 23.8 GHz derived from this tip(tnd23I)
• 31.4 GHz sky signal(tipsky31)
• Noise injection temp at 31.4 GHz derived from this tip(tnd31I)
• Temperature correction coefficient at 31.4 GHz(tc31)
• Noise injection temp at nominal temperature at 31.4 GHz(tnd_nom31)
• 23.8 GHz sky signal(tipsky23)
• Total water vapor along zenith path using tip-derived brightness temperatures(vaptip)
• Noise injection temp at nominal temperature at 23.8 GHz(tnd_nom23)
• 31.4 GHz sky brightness temperature derived from tip curve(tbsky31tip)
• 31.4 GHz goodness-of-fit coefficient(r31)
• 23.8 GHz sky brightness temperature derived from tip curve(tbsky23tip)
• 23.8 GHz goodness-of-fit coefficient(r23)

• Flag indicating where the initial surface water measurements are from: 0-> SMOS,
  1-> AERI(water_flag)
• Fraction of data in averaging interval with water on Teflon window(water_flag_fraction)
• 23.8 GHz sky brightness temperature(23tbsky)
• Standard deviation about the mean for the IR brightness temperature(ir_temp_sdev)
• Number of data points averaged out of 15(number_obs_averaged)
• Standard deviation about the mean for the 31.4 GHz sky brightness temperature(tbsky31_sdev)
• Standard deviation about the mean for the total water vapor amount(vap_sdev)
• Averaged total liquid water along LOS path(liq)
• IR Brightness Temperature(ir_temp)
• Probability of level change in ratio of averaged brightness temps(prob_level_change)
• Standard deviation about the mean for the 23.8 GHz sky brightness temperature(tbsky23_sdev)
• Probability of slope change in ratio of averaged brightness temps(prob_slope_change)
• Probability of outlier in ratio of averaged brightness temps(prob_outlier)
• Sky brightness temperature at 23.8 GHz(tbsky23)
• Sky brightness temperature at 31.4 GHz(tbsky31)
• 31.4 GHz sky brightness temperature(31tbsky)
• Standard deviation about the mean for the total liquid water amount(liq_sdev)
• MWR column precipitable water vapor(vap)

• 31.4 GHz sky signal(sky31)
• Water on Teflon window (1=WET, 0=DRY)(wet_window)
• 31.4 GHz blac2body+noise injection signal(bbn31)
• Noise injection temp at nominal temperature at 31.4 GHz(tnd_nom31)
• 23.8 GHz sky signal(sky23)
• Sky brightness temperature at 31.4 GHz(tbsky31)
• Noise injection temp at 31.4 GHz adjusted to tkbb(tnd31)
• Averaged total liquid water along LOS path(liq)
• Noise injection temp at nominal temperature at 23.8 GHz(tnd_nom23)
• 31.4 GHz blackbody(bb31)
• Temperature correction coefficient at 31.4 GHz(tc31)
• Blackbody kinetic temperature(tkbb)
• Sky Infra-Red Temperature(sky_ir_temp)
• MWR column precipitable water vapor(vap)
• Ambient temperature(tkair)
• 23.8 GHz Blackbody signal(bb23)
• Sky brightness temperature at 23.8 GHz(tbsky23)
• Mixer kinetic (physical) temperature(tkxc)
• (tknd)
• Noise injection temp at 23.8 GHz adjusted to tkbb(tnd23)
• 23.8 GHz blackbody+noise injection signal(bbn23)
• Temperature correction coefficient at 23.8 GHz(tc23)

• Sky brightness temperature at 23.8 GHz(tbsky23)
• Fraction of data in averaging interval flagged by Dynamic Linear Model as poten(dlm_flag_fraction)
• Standard deviation about the mean for the total water vapor amount(vap_sdev)
• 23.8 GHz sky brightness temperature(23tbsky)
• Standard deviation about the mean for the IR brightness temperature(ir_temp_sdev)
• IR Brightness Temperature(ir_temp)
• MWR column precipitable water vapor(vap)
• Number of contiguous periods in averaging interval flagged by Dynamic Linear Mo(dlm_flag_periods)
• Standard deviation about the mean for the 23.8 GHz sky brightness temperature(tbsky23_sdev)
• Standard deviation about the mean for the total liquid water amount(liq_sdev)
• Number of contiguous periods in averaging interval with water on Teflon window(water_flag_periods)
• Standard deviation about the mean for the 31.4 GHz sky brightness temperature(tbsky31_sdev)
• Fraction of data in averaging interval with water on Teflon window(water_flag_fraction)
• 31.4 GHz sky brightness temperature(31tbsky)
• Averaged total liquid water along LOS path(liq)
• Sky brightness temperature at 31.4 GHz(tbsky31)

SGP/MWR/C1 - Instrument offline

Instrument was taken offline and returned to manufacturer for repair.  Data are missing 
and unrecoverable.

• 31.4 GHz blackbody(bb31)
• Water on Teflon window (1=WET, 0=DRY)(wet_window)
• Actual elevation angle(actel)
• Blackbody kinetic temperature(tkbb)
• Ambient temperature(tkair)
• 23.8 GHz blackbody+noise injection signal(bbn23)
• 31.4 GHz sky signal(tipsky31)
• Temperature correction coefficient at 31.4 GHz(tc31)
• Noise injection temp at nominal temperature at 31.4 GHz(tnd_nom31)
• 23.8 GHz sky signal(tipsky23)
• Time offset of tweaks from base_time(time_offset)
• Noise injection temp at nominal temperature at 23.8 GHz(tnd_nom23)
• 31.4 GHz blac2body+noise injection signal(bbn31)
• Noise injection temp at 23.8 GHz adjusted to tkbb(tnd23)
• (tknd)
• Total liquid water along zenith path using tip-derived brightness temperatures(liqtip)
• Noise injection temp at 31.4 GHz adjusted to tkbb(tnd31)
• 23.8 GHz Blackbody signal(bb23)
• lat(lat)
• Temperature correction coefficient at 23.8 GHz(tc23)
• Mixer kinetic (physical) temperature(tkxc)
• Dummy altitude for Zeb(alt)
• Noise injection temp at 23.8 GHz derived from this tip(tnd23I)
• Noise injection temp at 31.4 GHz derived from this tip(tnd31I)
• Actual Azimuth(actaz)
• base time(base_time)
• lon(lon)
• Total water vapor along zenith path using tip-derived brightness temperatures(vaptip)
• 31.4 GHz sky brightness temperature derived from tip curve(tbsky31tip)
• 31.4 GHz goodness-of-fit coefficient(r31)
• 23.8 GHz sky brightness temperature derived from tip curve(tbsky23tip)
• 23.8 GHz goodness-of-fit coefficient(r23)

• Flag indicating where the initial surface water measurements are from: 0-> SMOS,
  1-> AERI(water_flag)
• Fraction of data in averaging interval with water on Teflon window(water_flag_fraction)
• 23.8 GHz sky brightness temperature(23tbsky)
• Standard deviation about the mean for the 31.4 GHz sky brightness temperature(tbsky31_sdev)
• Standard deviation about the mean for the total water vapor amount(vap_sdev)
• IR Brightness Temperature(ir_temp)
• Standard deviation about the mean for the 23.8 GHz sky brightness temperature(tbsky23_sdev)
• Probability of slope change in ratio of averaged brightness temps(prob_slope_change)
• Number of points included in the ir_temp ensemble(num_obs_irt)
• 31.4 GHz sky brightness temperature(31tbsky)
• Standard deviation about the mean for the total liquid water amount(liq_sdev)
• MWR column precipitable water vapor(vap)
• Dummy altitude for Zeb(alt)
• lat(lat)
• Standard deviation about the mean for the IR brightness temperature(ir_temp_sdev)
• Number of data points averaged out of 15(number_obs_averaged)
• base time(base_time)
• Averaged total liquid water along LOS path(liq)
• Probability of level change in ratio of averaged brightness temps(prob_level_change)
• lon(lon)
• Number of data points averaged for 23tbsky, 31tbsky, vap & liq(num_obs)
• Probability of outlier in ratio of averaged brightness temps(prob_outlier)
• Sky brightness temperature at 23.8 GHz(tbsky23)
• Sky brightness temperature at 31.4 GHz(tbsky31)
• Time offset of tweaks from base_time(time_offset)

• 31.4 GHz sky signal(sky31)
• Water on Teflon window (1=WET, 0=DRY)(wet_window)
• Noise injection temp at nominal temperature at 31.4 GHz(tnd_nom31)
• Sky brightness temperature at 31.4 GHz(tbsky31)
• Noise injection temp at 31.4 GHz adjusted to tkbb(tnd31)
• lon(lon)
• Noise injection temp at nominal temperature at 23.8 GHz(tnd_nom23)
• Temperature correction coefficient at 31.4 GHz(tc31)
• MWR column precipitable water vapor(vap)
• 23.8 GHz Blackbody signal(bb23)
• Time offset of tweaks from base_time(time_offset)
• (tknd)
• 23.8 GHz blackbody+noise injection signal(bbn23)
• Temperature correction coefficient at 23.8 GHz(tc23)
• Dummy altitude for Zeb(alt)
• 31.4 GHz blac2body+noise injection signal(bbn31)
• 23.8 GHz sky signal(sky23)
• Averaged total liquid water along LOS path(liq)
• 31.4 GHz blackbody(bb31)
• Blackbody kinetic temperature(tkbb)
• Sky Infra-Red Temperature(sky_ir_temp)
• Ambient temperature(tkair)
• Sky brightness temperature at 23.8 GHz(tbsky23)
• Mixer kinetic (physical) temperature(tkxc)
• base time(base_time)
• Noise injection temp at 23.8 GHz adjusted to tkbb(tnd23)
• lat(lat)

• Sky brightness temperature at 23.8 GHz(tbsky23)
• Fraction of data in averaging interval flagged by Dynamic Linear Model as poten(dlm_flag_fraction)
• 23.8 GHz sky brightness temperature(23tbsky)
• Standard deviation about the mean for the IR brightness temperature(ir_temp_sdev)
• IR Brightness Temperature(ir_temp)
• MWR column precipitable water vapor(vap)
• Time offset of tweaks from base_time(time_offset)
• Number of contiguous periods in averaging interval flagged by Dynamic Linear Mo(dlm_flag_periods)
• lat(lat)
• lon(lon)
• base time(base_time)
• Number of points included in the ir_temp ensemble(num_obs_irt)
• Standard deviation about the mean for the 31.4 GHz sky brightness temperature(tbsky31_sdev)
• Dummy altitude for Zeb(alt)
• Averaged total liquid water along LOS path(liq)
• Standard deviation about the mean for the total water vapor amount(vap_sdev)
• Number of data points averaged for 23tbsky, 31tbsky, vap & liq(num_obs)
• Standard deviation about the mean for the 23.8 GHz sky brightness temperature(tbsky23_sdev)
• Standard deviation about the mean for the total liquid water amount(liq_sdev)
• Number of data points averaged for ir_temp(num_obs_ir)
• Number of contiguous periods in averaging interval with water on Teflon window(water_flag_periods)
• Fraction of data in averaging interval with water on Teflon window(water_flag_fraction)
• 31.4 GHz sky brightness temperature(31tbsky)
• Sky brightness temperature at 31.4 GHz(tbsky31)

SGP/SONDE/C1 - Bad RH Data

The RH values during this sounding oscillate between reasonable values and near-zero 
values.  The oscillation is due to failure of the RH sensor heating process.

• Surface dew point temperature(dp)
• Relative humidity inside the instrument enclosure(rh)

SGP/SONDE/C1 - Sonde RH values incorrect

RH values for all sondes launched during this time were incorrect due to a faulty Ground 
Check set which damaged or conditioned the RH sensor improperly.

• Surface dew point temperature(dp)
• Relative humidity inside the instrument enclosure(rh)

SGP/SONDE/C1 - Mixed use of RS92-SGP and RS92-KL radiosondes

Because of a manufacturer's production problem, we will be using both RS92-SGP (GPS 
windfinding and RS92-KL (Loran windfinding) radiosondes at the SGP/CF starting February 10, 
2006.  The radiosonde type used for the each sounding may be determined by looking the 
metadata variable "launch_status" in the netCDF data files.

• lon(lon)
• U-component(u_wind)
• Mean Wind Speed(wspd)
• V-component(v_wind)
• lat(lat)
• Wind Direction(deg)
• Wind Status(wstat)

SGP/SONDE/C1 - Soundings done as part of dual-sonde flights

The following soundings done during the subject time period were flown in dual-sonde mode 
in which the standard ARM RS92 radiosonde was attached to the same balloon with a NASA 
ATR (atmospheric temperature reference) radiosonde.  The radiosondes were separated by a 6' 
styrofoam bar.  To accommodate the additional weight, we used 1200g balloons rather than 
350g balloons.  Accordingly, we want to alert users that these soundings may reach 
higher altitudes than normal for ARM soundings and that the ascent rate may be somewhat 
higher.  The following soundings are affected:

Sequence  Date    UTC launch time
    1     2/22        0530
    2     2/22        1730
    3     2/22        2330 <---- No data: launch failure    
    4     2/23        0230
    5     2/23        0530
    6     2/23        1730    
    7     2/23        2030
    8     2/23        2330
    9     2/24        2330
   10     2/25        0215
   11     2/25        0509    
   12     2/25        1730
   13     2/25        1930
   14     2/25        2300

• Surface dew point temperature(dp)
• base time(base_time)
• Mean Wind Speed(wspd)
• U-component(u_wind)
• Relative humidity inside the instrument enclosure(rh)
• lat(lat)
• Ascent Rate(asc)
• Retrieved pressure profile(pres)
• Wind Direction(deg)
• Wind Status(wstat)
• lon(lon)
• Dry bulb temperature(tdry)
• Time offset of tweaks from base_time(time_offset)
• V-component(v_wind)
• Dummy altitude for Zeb(alt)

SGP/SONDE/C1 - DigiCORAIII failed, replaced with S01/S02 launches

The digiCORA-III failed on Saturday 2004-01-17.  The operators reported that they were 
unable to load the software and conduct normal soundings.	Following procedure, they 
conducted the regular soundings by using the S01/S02 systems as allowed by the AIRS IOP schedule.
The netCDF header fields "input_source" and "facility_id" will mention which of the 
S01/S02 systems was used in these launches.

• lon(lon)
• lat(lat)
• Dummy altitude for Zeb(alt)

• null(Raw data stream - documentation not supported)

SGP/SONDE/C1 - No Wind/Lat/Lon Data in Sonde Files

The wind finding hardware failed so that no wind or latitude/longitude data was collected 
on the launches for these days.

• lon(lon)
• U-component(u_wind)
• Mean Wind Speed(wspd)
• V-component(v_wind)
• lat(lat)
• Wind Status(wstat)

SGP/SONDE/C1 - RH values offset due to error in ground check

Background: After installation of the latest software update , we began performing formal 
ground checks on RS92 radiosondes.  By comparing the
radiosonde readings with reference values in a controlled environment, the
ground check is intended to ensure that the radiosonde sensors are in
calibration before launch.  The radisonde values during the ground check
process are recorded automatically; the reference values are entered by the
operator.  If the radiosonde readings vary from the reference values, the
system 'corrects' the radiosonde values.  In the case of RH, the correction
is applied as an offset (true RH = indicated RH + correction).

Problem: Some operators misunderstood the ground-check procedure and entered the 
radiosonde values of RH rather than the reference value (assumed 0%RH), thus, some soundings done 
during this period have RH values that are different from what they would be if the 
ground check procedure had been done correctly.

Consequence:  Because the RH corrections generally are small (averaging
about 0.5% RH) and the precision of the reported RH data during this time
period is 1% RH, some values will not be affected at all; others will be off by about 1% 
RH (still within the stated accuracy of the sensor). 
Furthermore, because entering the radiosonde value as the reference value
results in a near zero 'correction,' one may view these soundings as being
done without the ground check correction.  Also note that the dew point
value will be suspect as well.

I am attaching below a listing of the soundings that were affected during the indicated 
time period.  Users can see the magnitude of the problem and choose whether or not to apply 
an offset in RH.  Note that application of the offset to the processed RH data (in the 
netCDF file) will not have the same effect of applying the correction to the absolutely 
raw data (before processing), but the differences should be insignificant.  Also note that 
the corrections for each sounding are included in the netCDF header information.  These 
attributes are named 'humidity_correction' and 'humidity_correction_2'.  The values of RH 
indicated by the radiosonde while it is in the ground check set are in attributes 
'humidity_gc_sonde' and 'humidity_gc_sonde_2.'  There is an RH reading for each of the two RH 
sensors used in the RS92 radiosonde.

Here is the list - RH1 and RH2 are the radiosonde readings in the ground
check set.  Ref is the reference value entered by the operator.  The
correcte reference value should be 0%.  To obtain an approximation to the RH value that 
would have been recorded if the ground check had been done
properly, subtract the Ref value from the indicated RH.

 YYYYMMDD  HHMM  SerialN      RH1     RH2     Ref
 20060827  2332  B2624322    1.00    1.00    1.00
 20060828  1731  B2634078    1.00    1.00    1.00
 20060828  2332  B2624380    3.00    3.00    2.00
 20060909  2331  B2615266    1.00    1.00    1.00
 20060915  1759  B2914012    1.00    1.00    1.00
 20060919  2350  B2825128    1.00    1.00    1.00
 20060920  1800  B2825088    1.00    1.00    1.00
 20060920  2346  B2815633    1.00    1.00    1.00
 20060921  1728  B2834732    1.30    1.30    1.30
 20060921  2330  B2825042    1.50    1.50    1.50
 20060922  0527  B2825043    1.70    1.80    1.70
 20060922  1128  B2825031    1.60    1.50    1.60
 20060922  1729  B2834437    1.50    1.50    1.50
 20060922  2330  B2825040    0.40    0.50    0.50
 20060923  0529  B2834733    0.30    0.30    0.30
 20060923  1128  B2825026    0.40    0.40    0.40
 20060923  1729  B2825064    0.60    0.70    0.60
 20060923  2330  B2825041    0.40    0.50    0.50
 20060924  0529  B2825039    0.30    0.30    0.30
 20060924  1729  B2825025    0.20    0.30    0.20
 20060924  2329  B2825032    0.30    0.40    0.40
 20060925  0529  B2824234    0.20    0.30    0.20

• Surface dew point temperature(dp)
• Relative humidity inside the instrument enclosure(rh)

SGP/SONDE/C1 - Increased precision for alt, dp, pres, rh, tdry

The output precision of the following variables was increased 20060928

alt  changed from 1m to 0.1m
dp   changed from 0.1degC to 0.01degC
pres changed from 0.1 hPa to 0.01 hPa
RH   changed from 1%RH to 0.01%RH
tdry changed from .1degC to 0.01degC

Note that the increase in precision does not necessarily imply an increase in accuracy.  
Users are cautioned to continue to use their best scientific judgement when using these or 
any other data.

• Surface dew point temperature(dp)
• Dry bulb temperature(tdry)
• Relative humidity inside the instrument enclosure(rh)
• Retrieved pressure profile(pres)
• Dummy altitude for Zeb(alt)

SGP/MWR/B6 - Computer failure; Data missing

The computer powered off and it was not possible to restart it remotely. Data are missing 
between 9/8 and 9/12.

• Noise injection temp at 23.8 GHz adjusted to tkbb(tnd23)
• lon(lon)
• base time(base_time)
• 31.4 GHz goodness-of-fit coefficient(r31)
• 31.4 GHz sky signal(tipsky31)
• 23.8 GHz goodness-of-fit coefficient(r23)
• 31.4 GHz blac2body+noise injection signal(bbn31)
• (tknd)
• 23.8 GHz sky signal(tipsky23)
• Actual elevation angle(actel)
• 23.8 GHz Blackbody signal(bb23)
• Blackbody kinetic temperature(tkbb)
• 31.4 GHz blackbody(bb31)
• Mixer kinetic (physical) temperature(tkxc)
• Temperature correction coefficient at 31.4 GHz(tc31)
• Dummy altitude for Zeb(alt)
• Ambient temperature(tkair)
• Noise injection temp at 31.4 GHz adjusted to tkbb(tnd31)
• Total liquid water along zenith path using tip-derived brightness temperatures(liqtip)
• 23.8 GHz blackbody+noise injection signal(bbn23)
• Total water vapor along zenith path using tip-derived brightness temperatures(vaptip)
• 23.8 GHz sky brightness temperature derived from tip curve(tbskytip23)
• lat(lat)
• Noise injection temp at nominal temperature at 31.4 GHz(tnd_nom31)
• Temperature correction coefficient at 23.8 GHz(tc23)
• Actual Azimuth(actaz)
• Water on Teflon window (1=WET, 0=DRY)(wet_window)
• 31.8 GHz sky brightness temperature derived from tip curve(tbskytip31)
• Noise injection temp at 31.4 GHz derived from this tip(tnd31I)
• Noise injection temp at 23.8 GHz derived from this tip(tnd23I)
• Time offset of tweaks from base_time(time_offset)
• Noise injection temp at nominal temperature at 23.8 GHz(tnd_nom23)

• null(Raw data stream - documentation not supported)

• Temperature correction coefficient at 31.4 GHz(tc31)
• Water on Teflon window (1=WET, 0=DRY)(wet_window)
• lon(lon)
• Dummy altitude for Zeb(alt)
• 23.8 GHz Blackbody signal(bb23)
• MWR column precipitable water vapor(vap)
• Mixer kinetic (physical) temperature(tkxc)
• Sky Infra-Red Temperature(sky_ir_temp)
• 31.4 GHz blackbody(bb31)
• lat(lat)
• Ambient temperature(tkair)
• Blackbody kinetic temperature(tkbb)
• 23.8 GHz blackbody+noise injection signal(bbn23)
• (tknd)
• Temperature correction coefficient at 23.8 GHz(tc23)
• 31.4 GHz sky signal(sky31)
• Noise injection temp at 31.4 GHz adjusted to tkbb(tnd31)
• IR Brightness Temperature(ir_temp)
• base time(base_time)
• Noise injection temp at 23.8 GHz adjusted to tkbb(tnd23)
• 23.8 GHz sky signal(sky23)
• 31.4 GHz blac2body+noise injection signal(bbn31)
• Averaged total liquid water along LOS path(liq)
• Noise injection temp at nominal temperature at 23.8 GHz(tnd_nom23)
• Time offset of tweaks from base_time(time_offset)
• Sky brightness temperature at 31.4 GHz(tbsky31)
• Noise injection temp at nominal temperature at 31.4 GHz(tnd_nom31)
• Sky brightness temperature at 23.8 GHz(tbsky23)

• Fraction of data in averaging interval with water on Teflon window(water_flag_fraction)
• Dummy altitude for Zeb(alt)
• Standard deviation about the mean for the total liquid water amount(liq_sdev)
• Time offset of tweaks from base_time(time_offset)
• lat(lat)
• Number of contiguous periods in averaging interval with water on Teflon window(water_flag_periods)
• 23.8 GHz sky brightness temperature(23tbsky)
• Fraction of data in averaging interval flagged by Dynamic Linear Model as poten(dlm_flag_fraction)
• 31.4 GHz sky brightness temperature(31tbsky)
• Number of points included in the ir_temp ensemble(num_obs_irt)
• Standard deviation about the mean for the total water vapor amount(vap_sdev)
• Standard deviation about the mean for the 23.8 GHz sky brightness temperature(tbsky23_sdev)
• Sky brightness temperature at 23.8 GHz(tbsky23)
• Number of data points averaged for ir_temp(num_obs_ir)
• IR Brightness Temperature(ir_temp)
• lon(lon)
• base time(base_time)
• Standard deviation about the mean for the 31.4 GHz sky brightness temperature(tbsky31_sdev)
• Sky brightness temperature at 31.4 GHz(tbsky31)
• Standard deviation about the mean for the IR brightness temperature(ir_temp_sdev)
• Averaged total liquid water along LOS path(liq)
• Number of data points averaged for 23tbsky, 31tbsky, vap & liq(num_obs)
• MWR column precipitable water vapor(vap)
• Number of contiguous periods in averaging interval flagged by Dynamic Linear Mo(dlm_flag_periods)

SGP/SONDE/C1 - RH Sensor failure

The differences between the two RH sensors on this sonde are unreasonably high (~20%).  As 
a result the reported RH values oscillate by this amount during the times the sensors 
are alternately heated.  After the heating stops, the reported RH comes from the sensor 
reading the higher value.  There is no way of knowing if this is the correct value.

• Surface dew point temperature(dp)
• Relative humidity inside the instrument enclosure(rh)

SGP/SONDE/C1 - Suspect RH profile from 150-350 m above ground level

Several radiosondes were noticed to have a very stark dry layer between 150 m and 350 m, 
where the RH dropped from approximately 60-80% (which I would take as close to the ambient 
conditions) to less than 2%.  The character of these dropouts look like instrument 
issues, as it only a handful of radiosondes that appear to be affected.  The quicklook images 
from the Raman lidar does not show any very dry layers, thus supporting the hypothesis 
that the RH measurements from these radiosondes (at least in this small ~200 m level) are 
in error.  I should note that the temperature profiles look normal.

• Surface dew point temperature(dp)
• Relative humidity inside the instrument enclosure(rh)

SGP/5MWRAVG/B1/B4/B5 - Valid LWP > 1 mm excluded from 5 min avgs

Note: These data have not been and will not be reprocessed.  The MWRAVG VAP has been 
retired.

The limit of maximum valid liquid water path was set at 1 mm.  Although this limit was 
selected 'conservatively' so as to definitely flag precipitation-contaminated data in the 
20-second (sgpmwrlos) files, the effect has been to exclude valid liquid water paths 
greater than 1 mm from the 5-minute averages (sgp5mwravg).

The following actions are recommended:
1) the maximum limits for precipitable water vapor (PWV) and liquid water path (LWP) be 
removed and, 2) the averaging algorithm instead exclude data on the basis of the brightness 
temperature flags.  These flags are set below a minimum of 2.75 K (cosmic background) 
and above a maximum of 100 K (precipitation).

• MWR column precipitable water vapor(vap)
• Standard deviation about the mean for the total water vapor amount(vap_sdev)
• Standard deviation about the mean for the total liquid water amount(liq_sdev)
• Averaged total liquid water along LOS path(liq)

• Standard deviation about the mean for the total liquid water amount(liq_sdev)
• Standard deviation about the mean for the total water vapor amount(vap_sdev)
• MWR column precipitable water vapor(vap)
• Averaged total liquid water along LOS path(liq)

• Averaged total liquid water along LOS path(liq)
• Standard deviation about the mean for the total water vapor amount(vap_sdev)
• MWR column precipitable water vapor(vap)
• Standard deviation about the mean for the total liquid water amount(liq_sdev)

SGP/5MWRAVG/B6 - Valid LWP > 1 mm excluded from 5 min avgs

Note: These data have not been and will not be reprocessed.  The MWRAVG VAP has been 
retired.

The limit of maximum valid liquid water path was set at 1 mm.  Although this limit was 
selected 'conservatively' so as to definitely flag precipitation-contaminated data in the 
20-second (sgpmwrlos) files, the effect has been to exclude valid liquid water paths 
greater than 1 mm from the 5-minute averages (sgp5mwravg).

The following actions are recommended:
1) the maximum limits for precipitable water vapor (PWV) and liquid water path (LWP) be 
removed and, 2) the averaging algorithm instead exclude data on the basis of the brightness 
temperature flags.  These flags are set below a minimum of 2.75 K (cosmic background) 
and above a maximum of 100 K (precipitation).

• Averaged total liquid water along LOS path(liq)
• Standard deviation about the mean for the total water vapor amount(vap_sdev)
• MWR column precipitable water vapor(vap)
• Standard deviation about the mean for the total liquid water amount(liq_sdev)

SGP/MWR/C1 - Valid LWP > 1mm excluded from 5 min avgs

The limit of maximum valid liquid water path was set at 1 mm.  Although
this limit was selected 'conservatively' so as to definitely flag
precipitation-contaminated data in the 20-second (sgpmwrlos) files,
the effect has been to exclude valid liquid water paths greater than 1
mm from the 5-minute averages (sgp5mwravg).

The maximum limits for precipitable water vapor (PWV) and liquid water
path (LWP) have been removed, and the averaging algorithm instead
excludes data on the basis of the brightness temperature flags.  These
flags are set below a minimum of 2.75 K (cosmic background) and above
a maximum of 100 K (precipitation).

• Averaged total liquid water along LOS path(liq)
• Standard deviation about the mean for the total liquid water amount(liq_sdev)

Precipitable Water Vapor (PWV) values at Hillsboro

DQR No:                               Platform: sgpmwrlos, sgp5mwravg

Subject: Precipitable Water Vapor (PWV) values at Hillsboro

Date Submitted:
Submitted By:    JIM LILJEGREN        _X_  Instrument Mentor
                                      ___  EST Member
                                      ___  Science Team Member
                                      ___  Other _____________________________
 
For questions or problems, please contact the ARM Experiment Center at
509-375-6898 or via email at dqr@arm.gov.

Platform/Measurement:
    What level data: a0,a1,c1

    What location was the data collected at: SGP B1 (Hillsboro, KS)
 
    Period of time in question
        Begin Date  12/07/95   Time   03:00    (GMT)
        End Date    12/07/95   Time   16:00    (GMT)

        Begin Date  12/08/95   Time   20:00    (GMT)
        End Date    12/10/95   Time   06:00    (GMT)

 Data should be labeled:
 ___  questionable                      _X_  All data fields affected
 _X_  incorrect                         ___  Only some data fields affected
 _X_  wrong calibration
 ___  others 
 
 Discussion of Problem:

The precipitable water vapor was negative which is unreasonable.  At the
same time the brightness temperature in the 23.8 GHz was less than that
in the 31.4 GHz for apparently clear skies.  This is also unreasonable.
The calibration needs to be checked and updated.

 
Other observations/measurements impacted by this problem:

none

Suggested Corrections of the Problem: (e.g. change calibration factor and
recompute, flag data with this comment, etc.)

Correct calibration.

Data Processing Notes                Date

• Water on Teflon window (1=WET, 0=DRY)(wet_window)
• MWR column precipitable water vapor(vap)
• Actual Azimuth(actaz)
• 31.4 GHz sky brightness temperature(31tbsky)
• 23.8 GHz sky brightness temperature(23tbsky)
• Actual elevation angle(actel)
• Dummy altitude for Zeb(alt)
• lat(lat)
• Averaged total liquid water along LOS path(liq)
• lon(lon)
• base time(base_time)
• IR Brightness Temperature(ir_temp)
• Time offset of tweaks from base_time(time_offset)

• MWR column precipitable water vapor(vap)
• Standard deviation about the mean for the 23.8 GHz sky brightness temperature(tbsky23_sdev)
• Standard deviation about the mean for the total water vapor amount(vap_sdev)
• Time offset of tweaks from base_time(time_offset)
• 31.4 GHz sky brightness temperature(31tbsky)
• lat(lat)
• lon(lon)
• Dummy altitude for Zeb(alt)
• base time(base_time)
• 23.8 GHz sky brightness temperature(23tbsky)
• Fraction of data in averaging interval with water on Teflon window(water_flag_fraction)
• Number of data points averaged for 23tbsky, 31tbsky, vap & liq(num_obs)
• Averaged total liquid water along LOS path(liq)
• Standard deviation about the mean for the total liquid water amount(liq_sdev)
• Standard deviation about the mean for the 31.4 GHz sky brightness temperature(tbsky31_sdev)

• 31.4 GHz blackbody(31bb)
• Which LOS configuration(losn)
• Averaged total liquid water along LOS path(liq)
• 23.8 GHz sky brightness temperature(23tbsky)
• 31.4 GHz sky signal(31sky)
• Time offset of tweaks from base_time(time_offset)
• base time(base_time)
• Water on Teflon window (1=WET, 0=DRY)(wet_window)
• Actual Azimuth(actaz)
• 23.8 GHz noise injection brightness temperature(23unoise)
• 23.8 GHz Blackbody signal(23bb)
• 31.4 GHz sky+noise injection signal(31skyn)
• MWR column precipitable water vapor(vap)
• 23.8 GHz sky+noise injection signal(23skyn)
• Blackbody kinetic temperature(tkbb)
• 31.4 GHz sky brightness temperature(31tbsky)
• Dummy altitude for Zeb(alt)
• 31.4 GHz noise injection brightness temperature(31unoise)
• lat(lat)
• 31.4 GHz blackbody+noise injection signal(31bbn)
• 23.8 GHz blackbody+noise injection signal(23bbn)
• Mixer kinetic (physical) temperature(tkxc)
• Actual elevation angle(actel)
• 23.8 GHz sky signal(23sky)
• lon(lon)
• IR Brightness Temperature(ir_temp)

SGP/MWR/B1/B4/B5 - Reprocess: Error in MWR calibration

The effect of this error is small.  At most, it results in a bias of
about -0.015 cm in precipitable water vapor and -0.015 mm in liquid
water path during clear sky conditions.  The error is largest when the
brightness temperatures are small (i.e.  clear skies and low PWV).

The error results from failing to correctly account for the effect of
the Teflon window covering the radiometer mirror.  Although the
contribution of the window is subtracted when the tip curve data are
reduced to determine the true zenith brightness temperature, it is not
added back in when the zenith brightness temperature is used to
calibrate the noise diode.  This would still not be a problem if the
contribution of the window where not subtracted (again) during zenith
line-of-sight (LOS) operations.  But it is and the net effect is to
subtract the contribution of the window twice.

The calibrations ('Noise Injection Temperatures') are off by a factor
of 1.00164 and 1.00217 for the 23.8 and 31.4 GHz frequencies,
respectively.

The magnitude of the error is equal to the emissivity of the window
multiplied by the difference between the brightness temperature and the
temperature of the window.  The latter is taken to be equal to the
temperature of the internal blackbody target (which is about 10 deg C
above ambient.)  The emissivity of the window is 0.00164 at 23.8 GHz
and 0.00217 at 31.4 GHz.  For a reference temperature of 292.6 K and
brightness temperatures of 32.3 and 20.8 K at 23.8 and 31.4 GHz
respectively, this amounts to errors of -0.43 and -0.59 K at the
respective frequencies.  The average PWV for this date (5 April 1995)
was 1.4 cm.

At higher levels of PWV and for cloudy conditions, the brightness
temperatures are higher and so the error is smaller.

I will adjust the calibrations of all SGP radiometers to account
for this problem by the end of tomorrow (4 April 1996).

• MWR column precipitable water vapor(vap)
• Standard deviation about the mean for the total water vapor amount(vap_sdev)
• Standard deviation about the mean for the total liquid water amount(liq_sdev)
• Averaged total liquid water along LOS path(liq)

• Standard deviation about the mean for the total liquid water amount(liq_sdev)
• Standard deviation about the mean for the total water vapor amount(vap_sdev)
• MWR column precipitable water vapor(vap)
• Averaged total liquid water along LOS path(liq)

• Averaged total liquid water along LOS path(liq)
• Standard deviation about the mean for the total water vapor amount(vap_sdev)
• MWR column precipitable water vapor(vap)
• Standard deviation about the mean for the total liquid water amount(liq_sdev)

SGP/MWR/B6 - Reprocess: Error in MWR calibration

The effect of this error is small.  At most, it results in a bias of
about -0.015 cm in precipitable water vapor and -0.015 mm in liquid
water path during clear sky conditions.  The error is largest when the
brightness temperatures are small (i.e.  clear skies and low PWV).

The error results from failing to correctly account for the effect of
the Teflon window covering the radiometer mirror.  Although the
contribution of the window is subtracted when the tip curve data are
reduced to determine the true zenith brightness temperature, it is not
added back in when the zenith brightness temperature is used to
calibrate the noise diode.  This would still not be a problem if the
contribution of the window where not subtracted (again) during zenith
line-of-sight (LOS) operations.  But it is and the net effect is to
subtract the contribution of the window twice.

The calibrations ('Noise Injection Temperatures') are off by a factor
of 1.00164 and 1.00217 for the 23.8 and 31.4 GHz frequencies,
respectively.

The magnitude of the error is equal to the emissivity of the window
multiplied by the difference between the brightness temperature and the
temperature of the window.  The latter is taken to be equal to the
temperature of the internal blackbody target (which is about 10 deg C
above ambient.)  The emissivity of the window is 0.00164 at 23.8 GHz
and 0.00217 at 31.4 GHz.  For a reference temperature of 292.6 K and
brightness temperatures of 32.3 and 20.8 K at 23.8 and 31.4 GHz
respectively, this amounts to errors of -0.43 and -0.59 K at the
respective frequencies.  The average PWV for this date (5 April 1995)
was 1.4 cm.

At higher levels of PWV and for cloudy conditions, the brightness
temperatures are higher and so the error is smaller.

I will adjust the calibrations of all SGP radiometers to account
for this problem by the end of tomorrow (4 April 1996).

• Averaged total liquid water along LOS path(liq)
• Standard deviation about the mean for the total water vapor amount(vap_sdev)
• MWR column precipitable water vapor(vap)
• Standard deviation about the mean for the total liquid water amount(liq_sdev)

SGP/MWR/B1/B4/B5 - Reprocess: MWR Tuning Functions

The 'tuning functions' used to adjust the equivalent brightness
temperatures (TBs) measured by the ARM microwave radiometers (MWRs) are
now believed to be both incorrect and unnecessary.  They should no longer
be used and the data (going back to 1992) that incorporated them should
be reprocessed.  By eliminating these tuning functions the radiometer
retrievals would be independent of the soundings.

BACKGROUND

A recent comparison by Barry Lesht (ANL) of the precipitable water
vapor (PWV) retrieved from the MWR-measured brightness temperatures
against PWV derived by integrating along the trajectory of radiosonde
ascents has revealed that the MWR values are about 90% of those derived
from the soundings.  This is directly attributable to the slope of the
tuning function for the vapor-sensing channel (23.8 GHz) of 0.915 which
is applied to the measured brightness temperatures prior to retrieval
of PWV.

The rationale behind the use of the tuning functions is that the
radiation model (Liebe 87), on which the retrieval is based, is
imperfect whereas the radiosondes represent 'ground truth.'  Thus the
observed brightness temperatures must be adjusted to match those
calculated with the model using co-located soundings so that the
retrieval yields precipitable vapor amounts that agree with the
soundings.

Tuning functions were developed for the present ARM MWRs using
co-located soundings launched between October 1992 and December 1993.
These were adjusted slightly in January 1995 to account for the effects
of the 1-point calibration check performed prior to launch (see DQR
P950110.1):

     23.8 GHz:  TB_model = 0.789 + 0.915 TB_measured  (R2 = 0.998)
     31.4 GHz:  TB_model = 1.142 + 0.910 TB_measured  (R2 = 0.984)

However, repeating this exercise for soundings launched during 1994 and
1995 (excepting those that were mis-calibrated by the manufacturer; see
D960229.1) it now appears that the model-calculated
brightness temperatures are in much closer agreement with the measured
values and that the tuning functions account more for variations in the
radiosonde calibration than for any deficiencies in the radiation
model.  

Consequently, it appears that the present tuning functions are
incorrect and bias the retrieved PWV low by 10%.  In addition, given
the present agreement between measured and modeled brightness
temperatures, the tuning functions are also unnecessary.

METHODOLOGY

Brightness temperatures measured with microwave radiometer (MWR) serial
number 10, which was deployed at the central facility in December 1993,
have been compared against calculations using measurements from the
co-located Balloon-Borne Sounding System (BBSS).  The results are
summarized in two tables.  In each table, the calibration dates of the
sondes and MWR are listed as well as the time period and number of
samples included in each regression.  Each MWR sample is a 40-minute
average, centered on the time of the sonde launch, of the microwave
brightness temperature.  In order to include only clear sky conditions,
samples for which the standard deviation of the liquid-sensing (31.4
GHz) channel exceeded 0.3 K were eliminated.  To assure that the water
vapor was reasonably homogeneous horizontally, samples for which the
standard deviation in the vapor-sensing (23.8 GHz) channel exceeded 0.4
K (in 1995) or 0.5 K (in 1994) were eliminated.  The 1994 threshold is
larger in order to increase the number of samples and reduce the
standard error in the results.

The microwave radiometer measurements used in this comparison have been
reprocessed to account for calibration changes and other problems (see
P940813.1)

                            TB vs PWV

The first table is a comparison of microwave brightness temperature
(TB_mwr) regressed against the precipitable water vapor (PWV) computed
by integrating along the trajectory of the radiosonde ascent.  The
sondes launched during May - December 1994 are compared against two
sets of MWR data; the first uses the May 1994 calibration, and the
second uses the calibration of July 1994.  A comparison is also made of
TB_model vs PWV ('Liebe87') for reference.

The intercepts indicate the contribution due to molecular oxygen (i.e.
the tail of the 60 GHz line) which is affected by temperature and
pressure.  Note that the 'Liebe87' intercepts vary seasonally as the
temperature changes.  Note also that the effect of MWR calibration
changes is most evident in the intercept: offsets of 1-2 K are
observed.  Because the MWR calibration values represent the slope of
the radiometer equation (see Appendix), the magnitude of the offset is
largest at 0 K (i.e. the intercept) and declines to zero at ambient
temperature (~290 K).

The slope of the regression is essentially unaffected by the MWR
calibration.  Variations in the slope of the regression correlate with
sonde calibration date.  The sondes calibrated in May 1994 or later
appear to yield much closer agreement between the measured brightness
temperatures and those calculated with the Liebe 87 model than those
calibrated in January 1994 or earlier, with which the present tuning
functions were developed.

TABLE 1.  Microwave brightness temperature vs. precipitable water vapor

Relationship:  TB_mwr (K) = intercept (K) + slope (K/cm) * PW_sonde (cm)
Standard Error of the intercepts and slopes are given in parentheses.

Date of   Date of  Period          ------ 23.8 GHz -----  ----- 31.4 GHz -----
Sonde Cal MWR tip  Covered    N    intercept   slope      intercept  slope

1991-93    92-93  Oct92-Dec93 91   6.7        14.7        8.1        5.3

1992,93   Dec 93  Jan-Feb 94  85   6.9(0.19)  15.8(0.26)  8.8(0.13)  5.6(0.17)
1992,93   Liebe87 Jan-Feb 94  85   6.5(0.02)  13.8(0.03)  8.9(0.07)  4.5(0.09)

 Jun 93   Dec 93      Apr 94  16  10.6(1.11)  14.8(0.55) 10.1(0.51)  5.6(0.25)
 Jun 93   Liebe87     Apr 94  16   6.9(0.05)  13.6(0.02)  8.1(0.09)  5.0(0.05)

1992,93   May 94  May-Jun 94  48   7.0(1.03)  14.9(0.45)  7.8(0.41)  5.7(0.17)
1992,93   Jul 94  May-Jun 94  48   5.1(1.03)  14.9(0.44)  6.6(0.39)  5.7(0.17)
1992,93   Liebe87 May-Jun 94  48   7.1(0.11)  13.5(0.05)  8.4(0.16)  4.9(0.07)

 Jan 94   Dec 93  Feb-May 94  95   7.6(0.27)  14.3(0.14)  8.5(0.15)  5.5(0.08)
 Jan 94   Liebe87 Feb-May 94  95   6.9(0.05)  13.6(0.02)  8.1(0.09)  5.0(0.05)

 May 94   May 94  Jun-Aug 94  78  12.3(1.04)  13.0(0.34) 11.0(0.39)  4.8(0.13)
 May 94   Jul 94  Jun-Aug 94  78  10.3(1.04)  13.1(0.34)  9.8(0.39)  4.8(0.13)
 May 94   Liebe87 Jun-Aug 94  78   7.8(0.22)  13.3(0.07)  8.6(0.29)  4.9(0.10)

 Jun 94   May 94  Jul-Dec 94  57   8.3(0.37)  13.6(0.21)  8.8(0.19)  5.2(0.11)
 Jun 94   Jul 94  Jul-Dec 94  57   6.4(0.37)  13.6(0.21)  7.7(0.18)  5.2(0.10)
 Jun 94   Liebe87 Jul-Dec 94  57   6.9(0.08)  13.5(0.04)  8.3(0.10)  4.9(0.06)

 Aug 94   May 94  Sep-Dec 94  90   7.4(0.15)  13.5(0.09)  8.8(0.11)  5.1(0.07)
 Aug 94   Jul 94  Sep-Dec 94  90   5.5(0.14)  13.6(0.09)  7.8(0.12)  5.0(0.07)
 Aug 94   Liebe87 Sep-Dec 94  90   6.8(0.05)  13.6(0.03)  8.6(0.09)  4.9(0.06)

• MWR column precipitable water vapor(vap)
• Averaged total liquid water along LOS path(liq)

• MWR column precipitable water vapor(vap)
• Averaged total liquid water along LOS path(liq)

• Averaged total liquid water along LOS path(liq)
• MWR column precipitable water vapor(vap)

SGP/MWR/B6 - Reprocess: MWR Tuning Functions

The 'tuning functions' used to adjust the equivalent brightness
temperatures (TBs) measured by the ARM microwave radiometers (MWRs) are
now believed to be both incorrect and unnecessary.  They should no longer
be used and the data (going back to 1992) that incorporated them should
be reprocessed.  By eliminating these tuning functions the radiometer
retrievals would be independent of the soundings.

BACKGROUND

A recent comparison by Barry Lesht (ANL) of the precipitable water
vapor (PWV) retrieved from the MWR-measured brightness temperatures
against PWV derived by integrating along the trajectory of radiosonde
ascents has revealed that the MWR values are about 90% of those derived
from the soundings.  This is directly attributable to the slope of the
tuning function for the vapor-sensing channel (23.8 GHz) of 0.915 which
is applied to the measured brightness temperatures prior to retrieval
of PWV.

The rationale behind the use of the tuning functions is that the
radiation model (Liebe 87), on which the retrieval is based, is
imperfect whereas the radiosondes represent 'ground truth.'  Thus the
observed brightness temperatures must be adjusted to match those
calculated with the model using co-located soundings so that the
retrieval yields precipitable vapor amounts that agree with the
soundings.

Tuning functions were developed for the present ARM MWRs using
co-located soundings launched between October 1992 and December 1993.
These were adjusted slightly in January 1995 to account for the effects
of the 1-point calibration check performed prior to launch (see DQR
P950110.1):

     23.8 GHz:  TB_model = 0.789 + 0.915 TB_measured  (R2 = 0.998)
     31.4 GHz:  TB_model = 1.142 + 0.910 TB_measured  (R2 = 0.984)

However, repeating this exercise for soundings launched during 1994 and
1995 (excepting those that were mis-calibrated by the manufacturer; see
D960229.1) it now appears that the model-calculated
brightness temperatures are in much closer agreement with the measured
values and that the tuning functions account more for variations in the
radiosonde calibration than for any deficiencies in the radiation
model.  

Consequently, it appears that the present tuning functions are
incorrect and bias the retrieved PWV low by 10%.  In addition, given
the present agreement between measured and modeled brightness
temperatures, the tuning functions are also unnecessary.

METHODOLOGY

Brightness temperatures measured with microwave radiometer (MWR) serial
number 10, which was deployed at the central facility in December 1993,
have been compared against calculations using measurements from the
co-located Balloon-Borne Sounding System (BBSS).  The results are
summarized in two tables.  In each table, the calibration dates of the
sondes and MWR are listed as well as the time period and number of
samples included in each regression.  Each MWR sample is a 40-minute
average, centered on the time of the sonde launch, of the microwave
brightness temperature.  In order to include only clear sky conditions,
samples for which the standard deviation of the liquid-sensing (31.4
GHz) channel exceeded 0.3 K were eliminated.  To assure that the water
vapor was reasonably homogeneous horizontally, samples for which the
standard deviation in the vapor-sensing (23.8 GHz) channel exceeded 0.4
K (in 1995) or 0.5 K (in 1994) were eliminated.  The 1994 threshold is
larger in order to increase the number of samples and reduce the
standard error in the results.

The microwave radiometer measurements used in this comparison have been
reprocessed to account for calibration changes and other problems (see
P940813.1)

                            TB vs PWV

The first table is a comparison of microwave brightness temperature
(TB_mwr) regressed against the precipitable water vapor (PWV) computed
by integrating along the trajectory of the radiosonde ascent.  The
sondes launched during May - December 1994 are compared against two
sets of MWR data; the first uses the May 1994 calibration, and the
second uses the calibration of July 1994.  A comparison is also made of
TB_model vs PWV ('Liebe87') for reference.

The intercepts indicate the contribution due to molecular oxygen (i.e.
the tail of the 60 GHz line) which is affected by temperature and
pressure.  Note that the 'Liebe87' intercepts vary seasonally as the
temperature changes.  Note also that the effect of MWR calibration
changes is most evident in the intercept: offsets of 1-2 K are
observed.  Because the MWR calibration values represent the slope of
the radiometer equation (see Appendix), the magnitude of the offset is
largest at 0 K (i.e. the intercept) and declines to zero at ambient
temperature (~290 K).

The slope of the regression is essentially unaffected by the MWR
calibration.  Variations in the slope of the regression correlate with
sonde calibration date.  The sondes calibrated in May 1994 or later
appear to yield much closer agreement between the measured brightness
temperatures and those calculated with the Liebe 87 model than those
calibrated in January 1994 or earlier, with which the present tuning
functions were developed.

TABLE 1.  Microwave brightness temperature vs. precipitable water vapor

Relationship:  TB_mwr (K) = intercept (K) + slope (K/cm) * PW_sonde (cm)
Standard Error of the intercepts and slopes are given in parentheses.

Date of   Date of  Period          ------ 23.8 GHz -----  ----- 31.4 GHz -----
Sonde Cal MWR tip  Covered    N    intercept   slope      intercept  slope

1991-93    92-93  Oct92-Dec93 91   6.7        14.7        8.1        5.3

1992,93   Dec 93  Jan-Feb 94  85   6.9(0.19)  15.8(0.26)  8.8(0.13)  5.6(0.17)
1992,93   Liebe87 Jan-Feb 94  85   6.5(0.02)  13.8(0.03)  8.9(0.07)  4.5(0.09)

 Jun 93   Dec 93      Apr 94  16  10.6(1.11)  14.8(0.55) 10.1(0.51)  5.6(0.25)
 Jun 93   Liebe87     Apr 94  16   6.9(0.05)  13.6(0.02)  8.1(0.09)  5.0(0.05)

1992,93   May 94  May-Jun 94  48   7.0(1.03)  14.9(0.45)  7.8(0.41)  5.7(0.17)
1992,93   Jul 94  May-Jun 94  48   5.1(1.03)  14.9(0.44)  6.6(0.39)  5.7(0.17)
1992,93   Liebe87 May-Jun 94  48   7.1(0.11)  13.5(0.05)  8.4(0.16)  4.9(0.07)

 Jan 94   Dec 93  Feb-May 94  95   7.6(0.27)  14.3(0.14)  8.5(0.15)  5.5(0.08)
 Jan 94   Liebe87 Feb-May 94  95   6.9(0.05)  13.6(0.02)  8.1(0.09)  5.0(0.05)

 May 94   May 94  Jun-Aug 94  78  12.3(1.04)  13.0(0.34) 11.0(0.39)  4.8(0.13)
 May 94   Jul 94  Jun-Aug 94  78  10.3(1.04)  13.1(0.34)  9.8(0.39)  4.8(0.13)
 May 94   Liebe87 Jun-Aug 94  78   7.8(0.22)  13.3(0.07)  8.6(0.29)  4.9(0.10)

 Jun 94   May 94  Jul-Dec 94  57   8.3(0.37)  13.6(0.21)  8.8(0.19)  5.2(0.11)
 Jun 94   Jul 94  Jul-Dec 94  57   6.4(0.37)  13.6(0.21)  7.7(0.18)  5.2(0.10)
 Jun 94   Liebe87 Jul-Dec 94  57   6.9(0.08)  13.5(0.04)  8.3(0.10)  4.9(0.06)

 Aug 94   May 94  Sep-Dec 94  90   7.4(0.15)  13.5(0.09)  8.8(0.11)  5.1(0.07)
 Aug 94   Jul 94  Sep-Dec 94  90   5.5(0.14)  13.6(0.09)  7.8(0.12)  5.0(0.07)
 Aug 94   Liebe87 Sep-Dec 94  90   6.8(0.05)  13.6(0.03)  8.6(0.09)  4.9(0.06)

• Averaged total liquid water along LOS path(liq)
• MWR column precipitable water vapor(vap)

SGP/MWR/C1 - Loss of thermal stabilization

Periodically during August and September 1995 all microwave radiometers
at the SGP CART generated error messages in the Site Operations Log
like:

  Time: Sat Aug 19 18:41:20 1995
  MWRLOS.C1, tkxc: Value above Maximum.

This indicates that the temperature of the microwave hardware
(specifically, the cross-coupler or "xc") exceeded its controlled
temperature (47-52 deg C) at which point it was no longer thermally
stabilized and the gain was uncontrolled.  During these periods which
typically last about 8 hours from about local noon until about sunset
the data behave anomalously and should be considered invalid.

Specifically the precipitable water vapor increases and the liquid
water path decreases (and becomes SIGNIFICANTLY NEGATIVE (-0.1 mm) on
clear sky days).  The RMS noise level in the data also increases
sharply.  The 'Tkxc' field appears ONLY in the a0-level data and does
NOT appear in either the a1 (mwrlos) or c1 (mwr5avg) files.  Therefore
THESE ANOMALOUS VALUES HAVE BEEN INCLUDED IN THE 5-MINUTE AVERAGES.

The microwave hardware is thermally stabilized to about +/- 0.1 deg C
by resistive heating.  When the internal temperature rises above the
set point the thermal stabilization of the instrument gain is lost.
>From an examination of the component temperature data it appears that
increasing the set point temperature to about 55 deg C (328 K) would
prevent a re-ocurrance of this problem at the SGP.  The manufacturer,
Radiometrics, concurs that raising the set point will fix this problem
and will not cause other problems.

I will have to carefully examine the MCTEX data to determine whether
this will be a problem for the TWP.  The manufacturer and I had
discussed this possibility prior to building the TWP MWRs (S/N 015,
016, and 017) and those instruments have set points above 50 deg C.
Note that MWR 018 has a set point near 52 deg C (like the TWP models)
but it still experienced a few loss-of-stabilization events.

Note that the instruments with the lowest set points had the most
loss-of-stabilization events.

• 31.4 GHz sky brightness temperature(31tbsky)
• Averaged total liquid water along LOS path(liq)
• MWR column precipitable water vapor(vap)
• 23.8 GHz sky brightness temperature(23tbsky)

• Sky brightness temperature at 31.4 GHz(tbsky31)
• Averaged total liquid water along LOS path(liq)
• MWR column precipitable water vapor(vap)
• Sky brightness temperature at 23.8 GHz(tbsky23)

• 23.8 GHz sky brightness temperature(23tbsky)
• Averaged total liquid water along LOS path(liq)
• MWR column precipitable water vapor(vap)
• 31.4 GHz sky brightness temperature(31tbsky)

• MWR column precipitable water vapor(vap)
• Sky brightness temperature at 23.8 GHz(tbsky23)
• Sky brightness temperature at 31.4 GHz(tbsky31)
• Averaged total liquid water along LOS path(liq)

SGP/MWR/C1 - Radio Frequency Interference during IOP

During the specified times a strong, continuous signal was 
measured by the 31.4 GHz of the MWR.  The signal was present
in all 31.4 GHz measurements including the sky measurement,
the internal reference target measurement, and the measurement
of the internal noise injection source from which the
instantaneous instrument gain is computed.

The source of the interference has not yet been identified.

Because the gain is computed using the difference of the
noise injection and target measurements, and because the
sky brightness temperature is computed relative to the
internal target temperature, the data appear anomalous
only for a period of an hour after the interference starts
and ends.  This is due to the low pass filter applied to
the instantaneous gain.  However the data should be
considered invalid or at least questionable during the
entire period for which the interference was present.

• Flag indicating where the initial surface water measurements are from: 0-> SMOS,
  1-> AERI(water_flag)
• Fraction of data in averaging interval with water on Teflon window(water_flag_fraction)
• 23.8 GHz sky brightness temperature(23tbsky)
• Standard deviation about the mean for the IR brightness temperature(ir_temp_sdev)
• Number of data points averaged out of 15(number_obs_averaged)
• base time(base_time)
• Standard deviation about the mean for the 31.4 GHz sky brightness temperature(tbsky31_sdev)
• Standard deviation about the mean for the total water vapor amount(vap_sdev)
• Averaged total liquid water along LOS path(liq)
• IR Brightness Temperature(ir_temp)
• Probability of level change in ratio of averaged brightness temps(prob_level_change)
• Standard deviation about the mean for the 23.8 GHz sky brightness temperature(tbsky23_sdev)
• lon(lon)
• Probability of slope change in ratio of averaged brightness temps(prob_slope_change)
• Number of data points averaged for 23tbsky, 31tbsky, vap & liq(num_obs)
• Probability of outlier in ratio of averaged brightness temps(prob_outlier)
• Sky brightness temperature at 23.8 GHz(tbsky23)
• Sky brightness temperature at 31.4 GHz(tbsky31)
• Number of points included in the ir_temp ensemble(num_obs_irt)
• 31.4 GHz sky brightness temperature(31tbsky)
• Standard deviation about the mean for the total liquid water amount(liq_sdev)
• Dummy altitude for Zeb(alt)
• MWR column precipitable water vapor(vap)
• Time offset of tweaks from base_time(time_offset)
• lat(lat)

• 31.4 GHz sky signal(sky31)
• Water on Teflon window (1=WET, 0=DRY)(wet_window)
• Dummy altitude for Zeb(alt)
• 31.4 GHz blac2body+noise injection signal(bbn31)
• Noise injection temp at nominal temperature at 31.4 GHz(tnd_nom31)
• 23.8 GHz sky signal(sky23)
• Sky brightness temperature at 31.4 GHz(tbsky31)
• lon(lon)
• Noise injection temp at 31.4 GHz adjusted to tkbb(tnd31)
• Averaged total liquid water along LOS path(liq)
• Noise injection temp at nominal temperature at 23.8 GHz(tnd_nom23)
• 31.4 GHz blackbody(bb31)
• Temperature correction coefficient at 31.4 GHz(tc31)
• Blackbody kinetic temperature(tkbb)
• Sky Infra-Red Temperature(sky_ir_temp)
• MWR column precipitable water vapor(vap)
• Ambient temperature(tkair)
• 23.8 GHz Blackbody signal(bb23)
• Sky brightness temperature at 23.8 GHz(tbsky23)
• Mixer kinetic (physical) temperature(tkxc)
• Time offset of tweaks from base_time(time_offset)
• base time(base_time)
• (tknd)
• Noise injection temp at 23.8 GHz adjusted to tkbb(tnd23)
• 23.8 GHz blackbody+noise injection signal(bbn23)
• Temperature correction coefficient at 23.8 GHz(tc23)
• lat(lat)

• 31.4 GHz blac2body+noise injection signal(bbn31)
• Noise injection temp at 31.4 GHz adjusted to tkbb(tnd31)
• Sky brightness temperature at 31.4 GHz(tbsky31)
• 23.8 GHz sky signal(sky23)
• Temperature correction coefficient at 23.8 GHz(tc23)
• MWR column precipitable water vapor(vap)
• (tknd)
• Sky brightness temperature at 23.8 GHz(tbsky23)
• Ambient temperature(tkair)
• Noise injection temp at nominal temperature at 23.8 GHz(tnd_nom23)
• 23.8 GHz Blackbody signal(bb23)
• Mixer kinetic (physical) temperature(tkxc)
• Water on Teflon window (1=WET, 0=DRY)(wet_window)
• 31.4 GHz sky signal(sky31)
• Dummy altitude for Zeb(alt)
• lon(lon)
• Temperature correction coefficient at 31.4 GHz(tc31)
• 31.4 GHz blackbody(bb31)
• Blackbody kinetic temperature(tkbb)
• lat(lat)
• Sky Infra-Red Temperature(sky_ir_temp)
• Noise injection temp at 23.8 GHz adjusted to tkbb(tnd23)
• Noise injection temp at nominal temperature at 31.4 GHz(tnd_nom31)
• Averaged total liquid water along LOS path(liq)
• 23.8 GHz blackbody+noise injection signal(bbn23)
• base time(base_time)
• Time offset of tweaks from base_time(time_offset)

Loss of thermal stabilization

DQR No:                               Platform: sgpmwrlos, sgp5mwravg, 
                                                sgpqmemwrlos

Subject: Loss of thermal stabilization

Date Submitted:
Submitted By:    JIM LILJEGREN        _X_  Instrument Mentor
                                      ___  EST Member
                                      ___  Science Team Member
                                      ___  Other _____________________________
 
For questions or problems, please contact the ARM Experiment Center at
509-375-6898 or via email at dqr@arm.gov.

Platform/Measurement:
      What level data: a0,a1,c1

    What location was the data collected at: SGP B1 (Hillsboro, KS)
                                             SGP B4 (Vici, OK)
                                             SGP B5 (Morris, OK)
                                             SGP B6 (Purcell, OK)
                                             SGP C1 (Lamont, OK) 

    Period of time in question  (see table below)

 Data should be labeled:
 ___  questionable                      ___  All data fields affected
 _X_  incorrect                         _X_  Only some data fields affected:
 ___  wrong calibration
 ___  others                                 "23tbsky","31tbsky","vap","liq"
 
 Discussion of Problem:

I pointed out in a previous DQR (P960405.1) that during August of 1994
and 1995 the microwave radiometers would lose thermal stabilization on
very hot, sunny days when the temperature in the radiometer enclosure
rose above the set point for thermal stabilization (~50 deg C).  Although
I had planned to travel to the SGP prior to August 1996 to adjust the
set points upward to prevent this problem from occuring this year, the
temperatures in July 1996 were hotter than in previous years and the
loss of stabilization problem occurred before I could make the needed
adjustment.

The purpose of this note is the identify the time periods for which
this problem occurred.  More specific information about the problem,
including how the problem is detected and its effect on the reported
values of integrated water vapor and integrated cloud liquid water are
provided in the earlier DQR.

It is useful to repeat here that when the thermal stabilization is
lost, the reported precipitable water vapor increases and the liquid
water path decreases (and becomes SIGNIFICANTLY NEGATIVE (-0.1 mm) on
clear sky days).  The RMS noise level in the data also increases
sharply.  THESE ANOMALOUS VALUES HAVE BEEN INCLUDED IN THE 5-MINUTE
AVERAGES.

LOCATION                BEGINNING DATE AND TIME    ENDING DATE AND TIME

C1 (Central Facility)  
                         1 July 96  18:25 GMT      2 July 96  02:00 GMT
                         2          16:45          3          02:30
                         3          17:40          4          02:15
                         4          15:50          4          17:10
                         5          17:00          6          03:30
                         6          16:00          7          03:00
                         7          20:20          8          01:30
                        18          20:00         18          23:45
                        19          18:30         20          01:20
                        20          19:45         21          02:25
                        21          17:00         22          02:20
                        22          19:30         23          23:00

B1 (Hillsboro, KS)
                         1 July 96  20:30          2 July 96  01:15
                         2          17:00          3          02:00
                        17          20:30         18          00:15
                        18          19:25         19          02:00
                        19          19:00         20          02:30
                        20          18:35         21          00:30
                        21          20:20         22          01:40
                        28          20:55         28          00:15

B4 (Vici, OK)            2 July 96  19:25          2 July 96  23:15
                         3          19:35          3          21:15
                         4          20:40          5          00:30
                         5          19:15          6          02:00
                         6          19:00          6          22:40
                         7          20:45          8          00:30
                        21          19:45         22          02:00

B5 (Morris, OK)
                         1 July 96  18:35          2 July 96  00:45
                         2          17:20          3          01:15
                         3          17:25          4          02:00
                         5          20:20          6          01:45
                         6          16:45          7          02:30
                         7          18:10          8          01:00
                        19          20:00         20          00:20
                        20          19:30         21          00:55
                        21          18:15         22          01:30
                        22          19:30         23          01:15
                        23          22:00         24          00:15

B6 (Purcell, OK)

                         1 July 96  20:15          2 July 96  00:10
                         2          18:40          3          00:05
                         3          20:40          4          00:35
                         4          20:15          5          00:10
                         5          19:45          6          01:15
                         6          19:10          7          01:40
                        19          21:30         19          23:00
                        20          20:15         21          00:05
                        21          21:45         22          01:00
                        22          21:45         23          00:00

Other observations/measurements impacted by this problem:

none

Suggested Corrections of the Problem: (e.g. change calibration factor and
recompute, flag data with this comment, etc.)

Flag with this comment.

• MWR column precipitable water vapor(vap)
• Dummy altitude for Zeb(alt)
• base time(base_time)
• 23.8 GHz sky brightness temperature(23tbsky)
• Fraction of data in averaging interval with water on Teflon window(water_flag_fraction)
• Number of data points averaged for 23tbsky, 31tbsky, vap & liq(num_obs)
• Averaged total liquid water along LOS path(liq)
• Standard deviation about the mean for the 23.8 GHz sky brightness temperature(tbsky23_sdev)
• 31.4 GHz sky brightness temperature(31tbsky)
• lon(lon)
• Standard deviation about the mean for the total water vapor amount(vap_sdev)
• Standard deviation about the mean for the total liquid water amount(liq_sdev)
• Time offset of tweaks from base_time(time_offset)
• Standard deviation about the mean for the 31.4 GHz sky brightness temperature(tbsky31_sdev)
• lat(lat)

Loss of thermal stabilization

DQR No:                               Platform: sgpmwrlos, sgp5mwravg, 
                                                sgpqmemwrlos

Subject: Loss of thermal stabilization

Date Submitted:
Submitted By:    JIM LILJEGREN        _X_  Instrument Mentor
                                      ___  EST Member
                                      ___  Science Team Member
                                      ___  Other _____________________________
 
For questions or problems, please contact the ARM Experiment Center at
509-375-6898 or via email at dqr@arm.gov.

Platform/Measurement:
      What level data: a0,a1,c1

    What location was the data collected at: SGP B1 (Hillsboro, KS)
                                             SGP B4 (Vici, OK)
                                             SGP B5 (Morris, OK)
                                             SGP B6 (Purcell, OK)
                                             SGP C1 (Lamont, OK) 

    Period of time in question  (see table below)

 Data should be labeled:
 ___  questionable                      ___  All data fields affected
 _X_  incorrect                         _X_  Only some data fields affected:
 ___  wrong calibration
 ___  others                                 "23tbsky","31tbsky","vap","liq"
 
 Discussion of Problem:

I pointed out in a previous DQR (P960405.1) that during August of 1994
and 1995 the microwave radiometers would lose thermal stabilization on
very hot, sunny days when the temperature in the radiometer enclosure
rose above the set point for thermal stabilization (~50 deg C).  Although
I had planned to travel to the SGP prior to August 1996 to adjust the
set points upward to prevent this problem from occuring this year, the
temperatures in July 1996 were hotter than in previous years and the
loss of stabilization problem occurred before I could make the needed
adjustment.

The purpose of this note is the identify the time periods for which
this problem occurred.  More specific information about the problem,
including how the problem is detected and its effect on the reported
values of integrated water vapor and integrated cloud liquid water are
provided in the earlier DQR.

It is useful to repeat here that when the thermal stabilization is
lost, the reported precipitable water vapor increases and the liquid
water path decreases (and becomes SIGNIFICANTLY NEGATIVE (-0.1 mm) on
clear sky days).  The RMS noise level in the data also increases
sharply.  THESE ANOMALOUS VALUES HAVE BEEN INCLUDED IN THE 5-MINUTE
AVERAGES.

LOCATION                BEGINNING DATE AND TIME    ENDING DATE AND TIME

C1 (Central Facility)  
                         1 July 96  18:25 GMT      2 July 96  02:00 GMT
                         2          16:45          3          02:30
                         3          17:40          4          02:15
                         4          15:50          4          17:10
                         5          17:00          6          03:30
                         6          16:00          7          03:00
                         7          20:20          8          01:30
                        18          20:00         18          23:45
                        19          18:30         20          01:20
                        20          19:45         21          02:25
                        21          17:00         22          02:20
                        22          19:30         23          23:00

B1 (Hillsboro, KS)
                         1 July 96  20:30          2 July 96  01:15
                         2          17:00          3          02:00
                        17          20:30         18          00:15
                        18          19:25         19          02:00
                        19          19:00         20          02:30
                        20          18:35         21          00:30
                        21          20:20         22          01:40
                        28          20:55         28          00:15

B4 (Vici, OK)            2 July 96  19:25          2 July 96  23:15
                         3          19:35          3          21:15
                         4          20:40          5          00:30
                         5          19:15          6          02:00
                         6          19:00          6          22:40
                         7          20:45          8          00:30
                        21          19:45         22          02:00

B5 (Morris, OK)
                         1 July 96  18:35          2 July 96  00:45
                         2          17:20          3          01:15
                         3          17:25          4          02:00
                         5          20:20          6          01:45
                         6          16:45          7          02:30
                         7          18:10          8          01:00
                        19          20:00         20          00:20
                        20          19:30         21          00:55
                        21          18:15         22          01:30
                        22          19:30         23          01:15
                        23          22:00         24          00:15

B6 (Purcell, OK)

                         1 July 96  20:15          2 July 96  00:10
                         2          18:40          3          00:05
                         3          20:40          4          00:35
                         4          20:15          5          00:10
                         5          19:45          6          01:15
                         6          19:10          7          01:40
                        19          21:30         19          23:00
                        20          20:15         21          00:05
                        21          21:45         22          01:00
                        22          21:45         23          00:00

Other observations/measurements impacted by this problem:

none

Suggested Corrections of the Problem: (e.g. change calibration factor and
recompute, flag data with this comment, etc.)

Flag with this comment.

• MWR column precipitable water vapor(vap)
• Time offset of tweaks from base_time(time_offset)
• Number of data points averaged for 23tbsky, 31tbsky, vap & liq(num_obs)
• 23.8 GHz sky brightness temperature(23tbsky)
• Standard deviation about the mean for the 31.4 GHz sky brightness temperature(tbsky31_sdev)
• Averaged total liquid water along LOS path(liq)
• Dummy altitude for Zeb(alt)
• Standard deviation about the mean for the 23.8 GHz sky brightness temperature(tbsky23_sdev)
• Standard deviation about the mean for the total water vapor amount(vap_sdev)
• lat(lat)
• base time(base_time)
• lon(lon)
• 31.4 GHz sky brightness temperature(31tbsky)
• Fraction of data in averaging interval with water on Teflon window(water_flag_fraction)
• Standard deviation about the mean for the total liquid water amount(liq_sdev)

Loss of thermal stabilization

DQR No:                               Platform: sgpmwrlos, sgp5mwravg, 
                                                sgpqmemwrlos

Subject: Loss of thermal stabilization

Date Submitted:
Submitted By:    JIM LILJEGREN        _X_  Instrument Mentor
                                      ___  EST Member
                                      ___  Science Team Member
                                      ___  Other _____________________________
 
For questions or problems, please contact the ARM Experiment Center at
509-375-6898 or via email at dqr@arm.gov.

Platform/Measurement:
      What level data: a0,a1,c1

    What location was the data collected at: SGP B1 (Hillsboro, KS)
                                             SGP B4 (Vici, OK)
                                             SGP B5 (Morris, OK)
                                             SGP B6 (Purcell, OK)
                                             SGP C1 (Lamont, OK) 

    Period of time in question  (see table below)

 Data should be labeled:
 ___  questionable                      ___  All data fields affected
 _X_  incorrect                         _X_  Only some data fields affected:
 ___  wrong calibration
 ___  others                                 "23tbsky","31tbsky","vap","liq"
 
 Discussion of Problem:

I pointed out in a previous DQR (P960405.1) that during August of 1994
and 1995 the microwave radiometers would lose thermal stabilization on
very hot, sunny days when the temperature in the radiometer enclosure
rose above the set point for thermal stabilization (~50 deg C).  Although
I had planned to travel to the SGP prior to August 1996 to adjust the
set points upward to prevent this problem from occuring this year, the
temperatures in July 1996 were hotter than in previous years and the
loss of stabilization problem occurred before I could make the needed
adjustment.

The purpose of this note is the identify the time periods for which
this problem occurred.  More specific information about the problem,
including how the problem is detected and its effect on the reported
values of integrated water vapor and integrated cloud liquid water are
provided in the earlier DQR.

It is useful to repeat here that when the thermal stabilization is
lost, the reported precipitable water vapor increases and the liquid
water path decreases (and becomes SIGNIFICANTLY NEGATIVE (-0.1 mm) on
clear sky days).  The RMS noise level in the data also increases
sharply.  THESE ANOMALOUS VALUES HAVE BEEN INCLUDED IN THE 5-MINUTE
AVERAGES.

LOCATION                BEGINNING DATE AND TIME    ENDING DATE AND TIME

C1 (Central Facility)  
                         1 July 96  18:25 GMT      2 July 96  02:00 GMT
                         2          16:45          3          02:30
                         3          17:40          4          02:15
                         4          15:50          4          17:10
                         5          17:00          6          03:30
                         6          16:00          7          03:00
                         7          20:20          8          01:30
                        18          20:00         18          23:45
                        19          18:30         20          01:20
                        20          19:45         21          02:25
                        21          17:00         22          02:20
                        22          19:30         23          23:00

B1 (Hillsboro, KS)
                         1 July 96  20:30          2 July 96  01:15
                         2          17:00          3          02:00
                        17          20:30         18          00:15
                        18          19:25         19          02:00
                        19          19:00         20          02:30
                        20          18:35         21          00:30
                        21          20:20         22          01:40
                        28          20:55         28          00:15

B4 (Vici, OK)            2 July 96  19:25          2 July 96  23:15
                         3          19:35          3          21:15
                         4          20:40          5          00:30
                         5          19:15          6          02:00
                         6          19:00          6          22:40
                         7          20:45          8          00:30
                        21          19:45         22          02:00

B5 (Morris, OK)
                         1 July 96  18:35          2 July 96  00:45
                         2          17:20          3          01:15
                         3          17:25          4          02:00
                         5          20:20          6          01:45
                         6          16:45          7          02:30
                         7          18:10          8          01:00
                        19          20:00         20          00:20
                        20          19:30         21          00:55
                        21          18:15         22          01:30
                        22          19:30         23          01:15
                        23          22:00         24          00:15

B6 (Purcell, OK)

                         1 July 96  20:15          2 July 96  00:10
                         2          18:40          3          00:05
                         3          20:40          4          00:35
                         4          20:15          5          00:10
                         5          19:45          6          01:15
                         6          19:10          7          01:40
                        19          21:30         19          23:00
                        20          20:15         21          00:05
                        21          21:45         22          01:00
                        22          21:45         23          00:00

Other observations/measurements impacted by this problem:

none

Suggested Corrections of the Problem: (e.g. change calibration factor and
recompute, flag data with this comment, etc.)

Flag with this comment.

• base time(base_time)
• lon(lon)
• Standard deviation about the mean for the total liquid water amount(liq_sdev)
• Standard deviation about the mean for the total water vapor amount(vap_sdev)
• Averaged total liquid water along LOS path(liq)
• Standard deviation about the mean for the 23.8 GHz sky brightness temperature(tbsky23_sdev)
• Fraction of data in averaging interval with water on Teflon window(water_flag_fraction)
• Number of data points averaged for 23tbsky, 31tbsky, vap & liq(num_obs)
• Time offset of tweaks from base_time(time_offset)
• Dummy altitude for Zeb(alt)
• lat(lat)
• MWR column precipitable water vapor(vap)
• Standard deviation about the mean for the 31.4 GHz sky brightness temperature(tbsky31_sdev)
• 23.8 GHz sky brightness temperature(23tbsky)
• 31.4 GHz sky brightness temperature(31tbsky)

Loss of thermal stabilization

DQR No:                               Platform: sgpmwrlos, sgp5mwravg, 
                                                sgpqmemwrlos

Subject: Loss of thermal stabilization

Date Submitted:
Submitted By:    JIM LILJEGREN        _X_  Instrument Mentor
                                      ___  EST Member
                                      ___  Science Team Member
                                      ___  Other _____________________________
 
For questions or problems, please contact the ARM Experiment Center at
509-375-6898 or via email at dqr@arm.gov.

Platform/Measurement:
      What level data: a0,a1,c1

    What location was the data collected at: SGP B1 (Hillsboro, KS)
                                             SGP B4 (Vici, OK)
                                             SGP B5 (Morris, OK)
                                             SGP B6 (Purcell, OK)
                                             SGP C1 (Lamont, OK) 

    Period of time in question  (see table below)

 Data should be labeled:
 ___  questionable                      ___  All data fields affected
 _X_  incorrect                         _X_  Only some data fields affected:
 ___  wrong calibration
 ___  others                                 "23tbsky","31tbsky","vap","liq"
 
 Discussion of Problem:

I pointed out in a previous DQR (P960405.1) that during August of 1994
and 1995 the microwave radiometers would lose thermal stabilization on
very hot, sunny days when the temperature in the radiometer enclosure
rose above the set point for thermal stabilization (~50 deg C).  Although
I had planned to travel to the SGP prior to August 1996 to adjust the
set points upward to prevent this problem from occuring this year, the
temperatures in July 1996 were hotter than in previous years and the
loss of stabilization problem occurred before I could make the needed
adjustment.

The purpose of this note is the identify the time periods for which
this problem occurred.  More specific information about the problem,
including how the problem is detected and its effect on the reported
values of integrated water vapor and integrated cloud liquid water are
provided in the earlier DQR.

It is useful to repeat here that when the thermal stabilization is
lost, the reported precipitable water vapor increases and the liquid
water path decreases (and becomes SIGNIFICANTLY NEGATIVE (-0.1 mm) on
clear sky days).  The RMS noise level in the data also increases
sharply.  THESE ANOMALOUS VALUES HAVE BEEN INCLUDED IN THE 5-MINUTE
AVERAGES.

LOCATION                BEGINNING DATE AND TIME    ENDING DATE AND TIME

C1 (Central Facility)  
                         1 July 96  18:25 GMT      2 July 96  02:00 GMT
                         2          16:45          3          02:30
                         3          17:40          4          02:15
                         4          15:50          4          17:10
                         5          17:00          6          03:30
                         6          16:00          7          03:00
                         7          20:20          8          01:30
                        18          20:00         18          23:45
                        19          18:30         20          01:20
                        20          19:45         21          02:25
                        21          17:00         22          02:20
                        22          19:30         23          23:00

B1 (Hillsboro, KS)
                         1 July 96  20:30          2 July 96  01:15
                         2          17:00          3          02:00
                        17          20:30         18          00:15
                        18          19:25         19          02:00
                        19          19:00         20          02:30
                        20          18:35         21          00:30
                        21          20:20         22          01:40
                        28          20:55         28          00:15

B4 (Vici, OK)            2 July 96  19:25          2 July 96  23:15
                         3          19:35          3          21:15
                         4          20:40          5          00:30
                         5          19:15          6          02:00
                         6          19:00          6          22:40
                         7          20:45          8          00:30
                        21          19:45         22          02:00

B5 (Morris, OK)
                         1 July 96  18:35          2 July 96  00:45
                         2          17:20          3          01:15
                         3          17:25          4          02:00
                         5          20:20          6          01:45
                         6          16:45          7          02:30
                         7          18:10          8          01:00
                        19          20:00         20          00:20
                        20          19:30         21          00:55
                        21          18:15         22          01:30
                        22          19:30         23          01:15
                        23          22:00         24          00:15

B6 (Purcell, OK)

                         1 July 96  20:15          2 July 96  00:10
                         2          18:40          3          00:05
                         3          20:40          4          00:35
                         4          20:15          5          00:10
                         5          19:45          6          01:15
                         6          19:10          7          01:40
                        19          21:30         19          23:00
                        20          20:15         21          00:05
                        21          21:45         22          01:00
                        22          21:45         23          00:00

Other observations/measurements impacted by this problem:

none

Suggested Corrections of the Problem: (e.g. change calibration factor and
recompute, flag data with this comment, etc.)

Flag with this comment.

• Standard deviation about the mean for the 31.4 GHz sky brightness temperature(tbsky31_sdev)
• Fraction of data in averaging interval with water on Teflon window(water_flag_fraction)
• lat(lat)
• Dummy altitude for Zeb(alt)
• lon(lon)
• 23.8 GHz sky brightness temperature(23tbsky)
• Standard deviation about the mean for the total liquid water amount(liq_sdev)
• base time(base_time)
• 31.4 GHz sky brightness temperature(31tbsky)
• Time offset of tweaks from base_time(time_offset)
• Averaged total liquid water along LOS path(liq)
• Number of data points averaged for 23tbsky, 31tbsky, vap & liq(num_obs)
• Standard deviation about the mean for the total water vapor amount(vap_sdev)
• MWR column precipitable water vapor(vap)
• Standard deviation about the mean for the 23.8 GHz sky brightness temperature(tbsky23_sdev)

Loss of thermal stabilization

DQR No:                               Platform: sgpmwrlos, sgp5mwravg, 
                                                sgpqmemwrlos

Subject: Loss of thermal stabilization

Date Submitted:
Submitted By:    JIM LILJEGREN        _X_  Instrument Mentor
                                      ___  EST Member
                                      ___  Science Team Member
                                      ___  Other _____________________________
 
For questions or problems, please contact the ARM Experiment Center at
509-375-6898 or via email at dqr@arm.gov.



Platform/Measurement:
      What level data: a0,a1,c1

    What location was the data collected at: SGP B1 (Hillsboro, KS)
                                             SGP B4 (Vici, OK)
                                             SGP B5 (Morris, OK)
                                             SGP B6 (Purcell, OK)
                                             SGP C1 (Lamont, OK) 

    Period of time in question  (see table below)



Data should be labeled:
 ___  questionable                      ___  All data fields affected
 _X_  incorrect                         _X_  Only some data fields affected:
___  wrong calibration
___  others                                 "23tbsky","31tbsky","vap","liq"

 Discussion of Problem:

I pointed out in a previous DQR (D960405.1) that during August of 1994
and 1995 the microwave radiometers would lose thermal stabilization on
very hot, sunny days when the temperature in the radiometer enclosure
rose above the set point for thermal stabilization (~50 deg C).  Although
I had planned to travel to the SGP prior to August 1996 to adjust the
set points upward to prevent this problem from occuring this year, the
temperatures in July 1996 were hotter than in previous years and the
loss of stabilization problem occurred before I could make the needed
adjustment.

The purpose of this note is the identify the time periods for which
this problem occurred.  More specific information about the problem,
including how the problem is detected and its effect on the reported
values of integrated water vapor and integrated cloud liquid water are
provided in the earlier DQR.

It is useful to repeat here that when the thermal stabilization is
lost, the reported precipitable water vapor increases and the liquid
water path decreases (and becomes SIGNIFICANTLY NEGATIVE (-0.1 mm) on
clear sky days).  The RMS noise level in the data also increases
sharply.  THESE ANOMALOUS VALUES HAVE BEEN INCLUDED IN THE 5-MINUTE
AVERAGES.

LOCATION                BEGINNING DATE AND TIME    ENDING DATE AND TIME

C1 (Central Facility)  
                         1 July 96  18:25 GMT      2 July 96  02:00 GMT
                         2          16:45          3          02:30
                         3          17:40          4          02:15
                         4          15:50          4          17:10
                         5          17:00          6          03:30
                         6          16:00          7          03:00
                         7          20:20          8          01:30
                        18          20:00         18          23:45
                        19          18:30         20          01:20
                        20          19:45         21          02:25
                        21          17:00         22          02:20
                        22          19:30         23          23:00

B1 (Hillsboro, KS)
                         1 July 96  20:30          2 July 96  01:15
                         2          17:00          3          02:00
                        17          20:30         18          00:15
                        18          19:25         19          02:00
                        19          19:00         20          02:30
                        20          18:35         21          00:30
                        21          20:20         22          01:40
                        28          20:55         28          00:15

B4 (Vici, OK)            2 July 96  19:25          2 July 96  23:15
                         3          19:35          3          21:15
                         4          20:40          5          00:30
                         5          19:15          6          02:00
                         6          19:00          6          22:40
                         7          20:45          8          00:30
                        21          19:45         22          02:00

B5 (Morris, OK)
                         1 July 96  18:35          2 July 96  00:45
                         2          17:20          3          01:15
                         3          17:25          4          02:00
                         5          20:20          6          01:45
                         6          16:45          7          02:30
                         7          18:10          8          01:00
                        19          20:00         20          00:20
                        20          19:30         21          00:55
                        21          18:15         22          01:30
                        22          19:30         23          01:15
                        23          22:00         24          00:15

B6 (Purcell, OK)

                         1 July 96  20:15          2 July 96  00:10
                         2          18:40          3          00:05
                         3          20:40          4          00:35
                         4          20:15          5          00:10
                         5          19:45          6          01:15
                         6          19:10          7          01:40
                        19          21:30         19          23:00
                        20          20:15         21          00:05
                        21          21:45         22          01:00
                        22          21:45         23          00:00

Other observations/measurements impacted by this problem:

none

Suggested Corrections of the Problem: (e.g. change calibration factor and
recompute, flag data with this comment, etc.)

Flag with this comment.

• MWR column precipitable water vapor(vap)
• Standard deviation about the mean for the 23.8 GHz sky brightness temperature(tbsky23_sdev)
• Standard deviation about the mean for the total water vapor amount(vap_sdev)
• Time offset of tweaks from base_time(time_offset)
• Standard deviation about the mean for the IR brightness temperature(ir_temp_sdev)
• 31.4 GHz sky brightness temperature(31tbsky)
• lat(lat)
• lon(lon)
• Dummy altitude for Zeb(alt)
• base time(base_time)
• 23.8 GHz sky brightness temperature(23tbsky)
• Fraction of data in averaging interval with water on Teflon window(water_flag_fraction)
• Number of data points averaged for 23tbsky, 31tbsky, vap & liq(num_obs)
• IR Brightness Temperature(ir_temp)
• Averaged total liquid water along LOS path(liq)
• Standard deviation about the mean for the total liquid water amount(liq_sdev)
• Standard deviation about the mean for the 31.4 GHz sky brightness temperature(tbsky31_sdev)

• lon(lon)
• Standard deviation about the mean for the 31.4 GHz sky brightness temperature(tbsky31_sdev)
• base time(base_time)
• Averaged total liquid water along LOS path(liq)
• Fraction of data in averaging interval with water on Teflon window(water_flag_fraction)
• IR Brightness Temperature(ir_temp)
• Dummy altitude for Zeb(alt)
• 31.4 GHz sky brightness temperature(31tbsky)
• Standard deviation about the mean for the total water vapor amount(vap_sdev)
• Standard deviation about the mean for the IR brightness temperature(ir_temp_sdev)
• Time offset of tweaks from base_time(time_offset)
• lat(lat)
• 23.8 GHz sky brightness temperature(23tbsky)
• Standard deviation about the mean for the total liquid water amount(liq_sdev)
• Standard deviation about the mean for the 23.8 GHz sky brightness temperature(tbsky23_sdev)
• Number of data points averaged for 23tbsky, 31tbsky, vap & liq(num_obs)
• MWR column precipitable water vapor(vap)

• Standard deviation about the mean for the IR brightness temperature(ir_temp_sdev)
• Standard deviation about the mean for the 23.8 GHz sky brightness temperature(tbsky23_sdev)
• MWR column precipitable water vapor(vap)
• Time offset of tweaks from base_time(time_offset)
• Number of data points averaged for 23tbsky, 31tbsky, vap & liq(num_obs)
• Averaged total liquid water along LOS path(liq)
• Dummy altitude for Zeb(alt)
• lat(lat)
• Fraction of data in averaging interval with water on Teflon window(water_flag_fraction)
• IR Brightness Temperature(ir_temp)
• 23.8 GHz sky brightness temperature(23tbsky)
• Standard deviation about the mean for the total liquid water amount(liq_sdev)
• Standard deviation about the mean for the 31.4 GHz sky brightness temperature(tbsky31_sdev)
• Standard deviation about the mean for the total water vapor amount(vap_sdev)
• base time(base_time)
• 31.4 GHz sky brightness temperature(31tbsky)
• lon(lon)

Loss of thermal stabilization

DQR No:                               Platform: sgpmwrlos, sgp5mwravg, 
                                                sgpqmemwrlos

Subject: Loss of thermal stabilization

Date Submitted:
Submitted By:    JIM LILJEGREN        _X_  Instrument Mentor
                                      ___  EST Member
                                      ___  Science Team Member
                                      ___  Other _____________________________
 
For questions or problems, please contact the ARM Experiment Center at
509-375-6898 or via email at dqr@arm.gov.

Platform/Measurement:
      What level data: a0,a1,c1

    What location was the data collected at: SGP B1 (Hillsboro, KS)
                                             SGP B4 (Vici, OK)
                                             SGP B5 (Morris, OK)
                                             SGP B6 (Purcell, OK)
                                             SGP C1 (Lamont, OK) 

    Period of time in question  (see table below)

 Data should be labeled:
 ___  questionable                      ___  All data fields affected
 _X_  incorrect                         _X_  Only some data fields affected:
 ___  wrong calibration
 ___  others                                 '23tbsky','31tbsky','vap','liq'
 
 Discussion of Problem:

I pointed out in a previous DQR (D960405.1) that during August of 1994
and 1995 the microwave radiometers would lose thermal stabilization on
very hot, sunny days when the temperature in the radiometer enclosure
rose above the set point for thermal stabilization (~50 deg C).  Although
I had planned to travel to the SGP prior to August 1996 to adjust the
set points upward to prevent this problem from occuring this year, the
temperatures in July 1996 were hotter than in previous years and the
loss of stabilization problem occurred before I could make the needed
adjustment.

The purpose of this note is the identify the time periods for which
this problem occurred.  More specific information about the problem,
including how the problem is detected and its effect on the reported
values of integrated water vapor and integrated cloud liquid water are
provided in the earlier DQR.

It is useful to repeat here that when the thermal stabilization is
lost, the reported precipitable water vapor increases and the liquid
water path decreases (and becomes SIGNIFICANTLY NEGATIVE (-0.1 mm) on
clear sky days).  The RMS noise level in the data also increases
sharply.  THESE ANOMALOUS VALUES HAVE BEEN INCLUDED IN THE 5-MINUTE
AVERAGES.

LOCATION                BEGINNING DATE AND TIME    ENDING DATE AND TIME

C1 (Central Facility)  
                         1 July 96  18:25 GMT      2 July 96  02:00 GMT
                         2          16:45          3          02:30
                         3          17:40          4          02:15
                         4          15:50          4          17:10
                         5          17:00          6          03:30
                         6          16:00          7          03:00
                         7          20:20          8          01:30
                        18          20:00         18          23:45
                        19          18:30         20          01:20
                        20          19:45         21          02:25
                        21          17:00         22          02:20
                        22          19:30         23          23:00

B1 (Hillsboro, KS)
                         1 July 96  20:30          2 July 96  01:15
                         2          17:00          3          02:00
                        17          20:30         18          00:15
                        18          19:25         19          02:00
                        19          19:00         20          02:30
                        20          18:35         21          00:30
                        21          20:20         22          01:40
                        28          20:55         28          00:15

B4 (Vici, OK)            2 July 96  19:25          2 July 96  23:15
                         3          19:35          3          21:15
                         4          20:40          5          00:30
                         5          19:15          6          02:00
                         6          19:00          6          22:40
                         7          20:45          8          00:30
                        21          19:45         22          02:00

B5 (Morris, OK)
                         1 July 96  18:35          2 July 96  00:45
                         2          17:20          3          01:15
                         3          17:25          4          02:00
                         5          20:20          6          01:45
                         6          16:45          7          02:30
                         7          18:10          8          01:00
                        19          20:00         20          00:20
                        20          19:30         21          00:55
                        21          18:15         22          01:30
                        22          19:30         23          01:15
                        23          22:00         24          00:15

B6 (Purcell, OK)

                         1 July 96  20:15          2 July 96  00:10
                         2          18:40          3          00:05
                         3          20:40          4          00:35
                         4          20:15          5          00:10
                         5          19:45          6          01:15
                         6          19:10          7          01:40
                        19          21:30         19          23:00
                        20          20:15         21          00:05
                        21          21:45         22          01:00
                        22          21:45         23          00:00

Other observations/measurements impacted by this problem:

none

Suggested Corrections of the Problem: (e.g. change calibration factor and
recompute, flag data with this comment, etc.)

Flag with this comment.

• IR Brightness Temperature(ir_temp)
• MWR column precipitable water vapor(vap)
• Time offset of tweaks from base_time(time_offset)
• Number of data points averaged for 23tbsky, 31tbsky, vap & liq(num_obs)
• Standard deviation about the mean for the IR brightness temperature(ir_temp_sdev)
• 23.8 GHz sky brightness temperature(23tbsky)
• Standard deviation about the mean for the 31.4 GHz sky brightness temperature(tbsky31_sdev)
• Averaged total liquid water along LOS path(liq)
• Standard deviation about the mean for the 23.8 GHz sky brightness temperature(tbsky23_sdev)
• Dummy altitude for Zeb(alt)
• Standard deviation about the mean for the total water vapor amount(vap_sdev)
• lat(lat)
• base time(base_time)
• lon(lon)
• 31.4 GHz sky brightness temperature(31tbsky)
• Fraction of data in averaging interval with water on Teflon window(water_flag_fraction)
• Standard deviation about the mean for the total liquid water amount(liq_sdev)

Loss of thermal stabilization

DQR No:                               Platform: sgpmwrlos, sgp5mwravg, 
                                                sgpqmemwrlos

Subject: Loss of thermal stabilization

Date Submitted:
Submitted By:    JIM LILJEGREN        _X_  Instrument Mentor
                                      ___  EST Member
                                      ___  Science Team Member
                                      ___  Other _____________________________
 
For questions or problems, please contact the ARM Experiment Center at
509-375-6898 or via email at dqr@arm.gov.

Platform/Measurement:
      What level data: a0,a1,c1

    What location was the data collected at: SGP B1 (Hillsboro, KS)
                                             SGP B4 (Vici, OK)
                                             SGP B5 (Morris, OK)
                                             SGP B6 (Purcell, OK)
                                             SGP C1 (Lamont, OK) 

    Period of time in question  (see table below)

 Data should be labeled:
 ___  questionable                      ___  All data fields affected
 _X_  incorrect                         _X_  Only some data fields affected:
 ___  wrong calibration
 ___  others                                 '23tbsky','31tbsky','vap','liq'
 
 Discussion of Problem:

I pointed out in a previous DQR (D960405.1) that during August of 1994
and 1995 the microwave radiometers would lose thermal stabilization on
very hot, sunny days when the temperature in the radiometer enclosure
rose above the set point for thermal stabilization (~50 deg C).  Although
I had planned to travel to the SGP prior to August 1996 to adjust the
set points upward to prevent this problem from occuring this year, the
temperatures in July 1996 were hotter than in previous years and the
loss of stabilization problem occurred before I could make the needed
adjustment.

The purpose of this note is the identify the time periods for which
this problem occurred.  More specific information about the problem,
including how the problem is detected and its effect on the reported
values of integrated water vapor and integrated cloud liquid water are
provided in the earlier DQR.

It is useful to repeat here that when the thermal stabilization is
lost, the reported precipitable water vapor increases and the liquid
water path decreases (and becomes SIGNIFICANTLY NEGATIVE (-0.1 mm) on
clear sky days).  The RMS noise level in the data also increases
sharply.  THESE ANOMALOUS VALUES HAVE BEEN INCLUDED IN THE 5-MINUTE
AVERAGES.

LOCATION                BEGINNING DATE AND TIME    ENDING DATE AND TIME

C1 (Central Facility)  
                         1 July 96  18:25 GMT      2 July 96  02:00 GMT
                         2          16:45          3          02:30
                         3          17:40          4          02:15
                         4          15:50          4          17:10
                         5          17:00          6          03:30
                         6          16:00          7          03:00
                         7          20:20          8          01:30
                        18          20:00         18          23:45
                        19          18:30         20          01:20
                        20          19:45         21          02:25
                        21          17:00         22          02:20
                        22          19:30         23          23:00

B1 (Hillsboro, KS)
                         1 July 96  20:30          2 July 96  01:15
                         2          17:00          3          02:00
                        17          20:30         18          00:15
                        18          19:25         19          02:00
                        19          19:00         20          02:30
                        20          18:35         21          00:30
                        21          20:20         22          01:40
                        28          20:55         28          00:15

B4 (Vici, OK)            2 July 96  19:25          2 July 96  23:15
                         3          19:35          3          21:15
                         4          20:40          5          00:30
                         5          19:15          6          02:00
                         6          19:00          6          22:40
                         7          20:45          8          00:30
                        21          19:45         22          02:00

B5 (Morris, OK)
                         1 July 96  18:35          2 July 96  00:45
                         2          17:20          3          01:15
                         3          17:25          4          02:00
                         5          20:20          6          01:45
                         6          16:45          7          02:30
                         7          18:10          8          01:00
                        19          20:00         20          00:20
                        20          19:30         21          00:55
                        21          18:15         22          01:30
                        22          19:30         23          01:15
                        23          22:00         24          00:15

B6 (Purcell, OK)

                         1 July 96  20:15          2 July 96  00:10
                         2          18:40          3          00:05
                         3          20:40          4          00:35
                         4          20:15          5          00:10
                         5          19:45          6          01:15
                         6          19:10          7          01:40
                        19          21:30         19          23:00
                        20          20:15         21          00:05
                        21          21:45         22          01:00
                        22          21:45         23          00:00

Other observations/measurements impacted by this problem:

none

Suggested Corrections of the Problem: (e.g. change calibration factor and
recompute, flag data with this comment, etc.)

Flag with this comment.

• base time(base_time)
• lon(lon)
• Standard deviation about the mean for the total liquid water amount(liq_sdev)
• Standard deviation about the mean for the total water vapor amount(vap_sdev)
• Averaged total liquid water along LOS path(liq)
• Standard deviation about the mean for the 23.8 GHz sky brightness temperature(tbsky23_sdev)
• Standard deviation about the mean for the IR brightness temperature(ir_temp_sdev)
• Fraction of data in averaging interval with water on Teflon window(water_flag_fraction)
• IR Brightness Temperature(ir_temp)
• Number of data points averaged for 23tbsky, 31tbsky, vap & liq(num_obs)
• Time offset of tweaks from base_time(time_offset)
• Dummy altitude for Zeb(alt)
• lat(lat)
• MWR column precipitable water vapor(vap)
• Standard deviation about the mean for the 31.4 GHz sky brightness temperature(tbsky31_sdev)
• 23.8 GHz sky brightness temperature(23tbsky)
• 31.4 GHz sky brightness temperature(31tbsky)

Loss of thermal stabilization

DQR No:                               Platform: sgpmwrlos, sgp5mwravg, 
                                                sgpqmemwrlos

Subject: Loss of thermal stabilization

Date Submitted:
Submitted By:    JIM LILJEGREN        _X_  Instrument Mentor
                                      ___  EST Member
                                      ___  Science Team Member
                                      ___  Other _____________________________
 
For questions or problems, please contact the ARM Experiment Center at
509-375-6898 or via email at dqr@arm.gov.

Platform/Measurement:
      What level data: a0,a1,c1

    What location was the data collected at: SGP B1 (Hillsboro, KS)
                                             SGP B4 (Vici, OK)
                                             SGP B5 (Morris, OK)
                                             SGP B6 (Purcell, OK)
                                             SGP C1 (Lamont, OK) 

    Period of time in question  (see table below)

 Data should be labeled:
 ___  questionable                      ___  All data fields affected
 _X_  incorrect                         _X_  Only some data fields affected:
 ___  wrong calibration
 ___  others                                 '23tbsky','31tbsky','vap','liq'
 
 Discussion of Problem:

I pointed out in a previous DQR (D960405.1) that during August of 1994
and 1995 the microwave radiometers would lose thermal stabilization on
very hot, sunny days when the temperature in the radiometer enclosure
rose above the set point for thermal stabilization (~50 deg C).  Although
I had planned to travel to the SGP prior to August 1996 to adjust the
set points upward to prevent this problem from occuring this year, the
temperatures in July 1996 were hotter than in previous years and the
loss of stabilization problem occurred before I could make the needed
adjustment.

The purpose of this note is the identify the time periods for which
this problem occurred.  More specific information about the problem,
including how the problem is detected and its effect on the reported
values of integrated water vapor and integrated cloud liquid water are
provided in the earlier DQR.

It is useful to repeat here that when the thermal stabilization is
lost, the reported precipitable water vapor increases and the liquid
water path decreases (and becomes SIGNIFICANTLY NEGATIVE (-0.1 mm) on
clear sky days).  The RMS noise level in the data also increases
sharply.  THESE ANOMALOUS VALUES HAVE BEEN INCLUDED IN THE 5-MINUTE
AVERAGES.

LOCATION                BEGINNING DATE AND TIME    ENDING DATE AND TIME

C1 (Central Facility)  
                         1 July 96  18:25 GMT      2 July 96  02:00 GMT
                         2          16:45          3          02:30
                         3          17:40          4          02:15
                         4          15:50          4          17:10
                         5          17:00          6          03:30
                         6          16:00          7          03:00
                         7          20:20          8          01:30
                        18          20:00         18          23:45
                        19          18:30         20          01:20
                        20          19:45         21          02:25
                        21          17:00         22          02:20
                        22          19:30         23          23:00

B1 (Hillsboro, KS)
                         1 July 96  20:30          2 July 96  01:15
                         2          17:00          3          02:00
                        17          20:30         18          00:15
                        18          19:25         19          02:00
                        19          19:00         20          02:30
                        20          18:35         21          00:30
                        21          20:20         22          01:40
                        28          20:55         28          00:15

B4 (Vici, OK)            2 July 96  19:25          2 July 96  23:15
                         3          19:35          3          21:15
                         4          20:40          5          00:30
                         5          19:15          6          02:00
                         6          19:00          6          22:40
                         7          20:45          8          00:30
                        21          19:45         22          02:00

B5 (Morris, OK)
                         1 July 96  18:35          2 July 96  00:45
                         2          17:20          3          01:15
                         3          17:25          4          02:00
                         5          20:20          6          01:45
                         6          16:45          7          02:30
                         7          18:10          8          01:00
                        19          20:00         20          00:20
                        20          19:30         21          00:55
                        21          18:15         22          01:30
                        22          19:30         23          01:15
                        23          22:00         24          00:15

B6 (Purcell, OK)

                         1 July 96  20:15          2 July 96  00:10
                         2          18:40          3          00:05
                         3          20:40          4          00:35
                         4          20:15          5          00:10
                         5          19:45          6          01:15
                         6          19:10          7          01:40
                        19          21:30         19          23:00
                        20          20:15         21          00:05
                        21          21:45         22          01:00
                        22          21:45         23          00:00

Other observations/measurements impacted by this problem:

none

Suggested Corrections of the Problem: (e.g. change calibration factor and
recompute, flag data with this comment, etc.)

Flag with this comment.

• Standard deviation about the mean for the 31.4 GHz sky brightness temperature(tbsky31_sdev)
• Fraction of data in averaging interval with water on Teflon window(water_flag_fraction)
• IR Brightness Temperature(ir_temp)
• lat(lat)
• Dummy altitude for Zeb(alt)
• lon(lon)
• 23.8 GHz sky brightness temperature(23tbsky)
• Standard deviation about the mean for the total liquid water amount(liq_sdev)
• base time(base_time)
• Standard deviation about the mean for the IR brightness temperature(ir_temp_sdev)
• 31.4 GHz sky brightness temperature(31tbsky)
• Time offset of tweaks from base_time(time_offset)
• Averaged total liquid water along LOS path(liq)
• Number of data points averaged for 23tbsky, 31tbsky, vap & liq(num_obs)
• Standard deviation about the mean for the total water vapor amount(vap_sdev)
• MWR column precipitable water vapor(vap)
• Standard deviation about the mean for the 23.8 GHz sky brightness temperature(tbsky23_sdev)

SGP/MWR/B1/B4/B5/B6/C1 - Thermal Stabilization Adjustment

In order to correct a thermal stabilization problem identified earlier
I adjusted the thermal set point of the microwave radiometers at the
SGP upward from 48-50 deg C to 55 deg C in early August 1996 according
to the schedule given below.

B6    5 August 1996
C1    6 August 1996
B1    7 August 1996
B5    8 August 1996

Subsequent to making this adjustment the MWRs were put in TIP mode to
check on whether the change in set point temperature affected their
calibration.  Because clear sky conditions were quite intermittent, it
is difficult to determine whether the substantial variability in the
tip data were attributable to the change in thermal set point.  The
instrument calibration was not altered in August.

Tip data were again collected with these instruments in September prior
to the beginning and at the close of the Water Vapor IOP.  For example,
the calibration of the instrument at the central facility (S/N 10)
derived from the September data was essentially the same as that
derived from calibration data acquired in February 1996.  Although this
would lead one to believe that altering the thermal set point did not
affect the instrument calibration, it may be that some transient effect
was induced.

In comparing soundings launched from the central facility with the
microwave radiometer there, I noticed that those sondes calibrated in
June 1996 consistently reported lower integrated water vapor than the
radiometer in July and September (during the IOP) but were in better
agreement with the radiometer for the two weeks period immediately
after the set point was adjusted.  I suspect that adjusting the thermal
set point may have temporarily increased the radiometer gain
(kelvins/volt) thereby lowering the measured brightness temperature and
the retrieved integrated water vapor.

It is not clear why a temporary change in gain should occur or even
whether it did.  But users of the data should be aware that the data
from the microwave radiometers at the SGP may be anomalous during
August 1996.

• MWR column precipitable water vapor(vap)
• 31.4 GHz sky brightness temperature(31tbsky)
• Averaged total liquid water along LOS path(liq)
• 23.8 GHz sky brightness temperature(23tbsky)

• 23.8 GHz sky brightness temperature(23tbsky)
• Averaged total liquid water along LOS path(liq)
• 31.4 GHz sky brightness temperature(31tbsky)
• MWR column precipitable water vapor(vap)

• 23.8 GHz sky brightness temperature(23tbsky)
• 31.4 GHz sky brightness temperature(31tbsky)
• Averaged total liquid water along LOS path(liq)
• MWR column precipitable water vapor(vap)

• 23.8 GHz sky brightness temperature(23tbsky)
• Averaged total liquid water along LOS path(liq)
• MWR column precipitable water vapor(vap)
• 31.4 GHz sky brightness temperature(31tbsky)

• Averaged total liquid water along LOS path(liq)
• 23.8 GHz sky brightness temperature(23tbsky)
• MWR column precipitable water vapor(vap)
• 31.4 GHz sky brightness temperature(31tbsky)

• Sky brightness temperature at 31.4 GHz(tbsky31)
• Averaged total liquid water along LOS path(liq)
• MWR column precipitable water vapor(vap)
• Sky brightness temperature at 23.8 GHz(tbsky23)

• Averaged total liquid water along LOS path(liq)
• 23.8 GHz sky brightness temperature(23tbsky)
• MWR column precipitable water vapor(vap)
• 31.4 GHz sky brightness temperature(31tbsky)

• 23.8 GHz sky brightness temperature(23tbsky)
• MWR column precipitable water vapor(vap)
• 31.4 GHz sky brightness temperature(31tbsky)
• Averaged total liquid water along LOS path(liq)

• Sky brightness temperature at 31.4 GHz(tbsky31)
• MWR column precipitable water vapor(vap)
• Sky brightness temperature at 23.8 GHz(tbsky23)
• Averaged total liquid water along LOS path(liq)

• Averaged total liquid water along LOS path(liq)
• 31.4 GHz sky brightness temperature(31tbsky)
• 23.8 GHz sky brightness temperature(23tbsky)
• MWR column precipitable water vapor(vap)

• MWR column precipitable water vapor(vap)
• 31.4 GHz sky brightness temperature(31tbsky)
• 23.8 GHz sky brightness temperature(23tbsky)
• Averaged total liquid water along LOS path(liq)

• MWR column precipitable water vapor(vap)
• 31.4 GHz sky brightness temperature(31tbsky)
• 23.8 GHz sky brightness temperature(23tbsky)
• Averaged total liquid water along LOS path(liq)

• Averaged total liquid water along LOS path(liq)
• 31.4 GHz sky brightness temperature(31tbsky)
• 23.8 GHz sky brightness temperature(23tbsky)
• MWR column precipitable water vapor(vap)

• 23.8 GHz sky brightness temperature(23tbsky)
• Averaged total liquid water along LOS path(liq)
• 31.4 GHz sky brightness temperature(31tbsky)
• MWR column precipitable water vapor(vap)

• MWR column precipitable water vapor(vap)
• Averaged total liquid water along LOS path(liq)
• 23.8 GHz sky brightness temperature(23tbsky)
• 31.4 GHz sky brightness temperature(31tbsky)

• Averaged total liquid water along LOS path(liq)
• MWR column precipitable water vapor(vap)
• 31.4 GHz sky brightness temperature(31tbsky)
• 23.8 GHz sky brightness temperature(23tbsky)

SGP/SONDE - Dry bias in sonde RH

Vaisala has confirmed ARM findings of an apparent dry bias in the
relative humidity measured by RS-80H radiosondes.  The cause of
the dry bias is thought to be contamination of the humidity sensor
by volatile organic substances originating from some plastic parts
of the radiosonde.  The amount of contamination is a function of
the time between the date of sonde manufacture and its use.  All
RS-80H sondes manufactured before week 34 of 1998 will show this
bias.  After week 34 of 1998 Vaisala changed its packaging to
reduce, but not eliminate the contamination problem.

Starting with RS-80 radiosonde manufactured in late June 2000 Vaisala
enclosed the sensor boom in an inert plastic shield, thereby eliminating
the contamination that caused the dry bias.

Starting in May 2001 at the SGP, May 2002 at the TWP, and later 2002
at the NSA, ARM has moved to using RS-90 radiosondes.  These sondes
are not subject to the contaminatino that caused the dry bias.

Vaisala is in the process of developing an algorithm that can be 
used to estimate the correct RH from knowledge of the sonde age.
All of the ARM sounding data have sufficient metadata available
to apply the correction.

Additionally, ARM has funded a Science Team effort (Milosevich) to
develop a 'best' correction algorithm for the RS-80 radiosonde humidity
data.  When completed this algorithm will allow us to reprocess the
accumulated RS-80 data and produce a new data platform with what we
hope will be more accurate data.

• null(Raw data stream - documentation not supported)

• (Development raw data stream - documentation not supported)

• null(Raw data stream - documentation not supported)

• Relative humidity inside the instrument enclosure(rh)
• Surface dew point temperature(dp)

• (Development raw data stream - documentation not supported)

• (Development data stream - documentation not supported)

• Surface dew point temperature(dp)
• Relative humidity inside the instrument enclosure(rh)

• (Development raw data stream - documentation not supported)

• Surface dew point temperature(dp)
• Relative humidity inside the instrument enclosure(rh)

• (Development data stream - documentation not supported)

• (Development data stream - documentation not supported)

• Relative humidity inside the instrument enclosure(rh)
• Surface dew point temperature(dp)

• null(Raw data stream - documentation not supported)

• null(Raw data stream - documentation not supported)

• (Development raw data stream - documentation not supported)

• (Development data stream - documentation not supported)

• Relative humidity inside the instrument enclosure(rh)
• Surface dew point temperature(dp)

• Surface dew point temperature(dp)
• Relative humidity inside the instrument enclosure(rh)

• null(Raw data stream - documentation not supported)

• Relative humidity inside the instrument enclosure(rh)
• Surface dew point temperature(dp)

• Relative humidity inside the instrument enclosure(rh)
• Surface dew point temperature(dp)

• Surface dew point temperature(dp)
• Relative humidity inside the instrument enclosure(rh)

• null(Raw data stream - documentation not supported)

• (Development raw data stream - documentation not supported)

• Surface dew point temperature(dp)
• Relative humidity inside the instrument enclosure(rh)

• null(Raw data stream - documentation not supported)

• null(Raw data stream - documentation not supported)

• (Development data stream - documentation not supported)

• (Development data stream - documentation not supported)

• (Development data stream - documentation not supported)

• (Development data stream - documentation not supported)

• null(Raw data stream - documentation not supported)

• Surface dew point temperature(dp)
• Relative humidity inside the instrument enclosure(rh)

• null(Raw data stream - documentation not supported)

• Surface dew point temperature(dp)
• Relative humidity inside the instrument enclosure(rh)

• (Development data stream - documentation not supported)

• (Development data stream - documentation not supported)

• (Development raw data stream - documentation not supported)

• Relative humidity inside the instrument enclosure(rh)
• Surface dew point temperature(dp)

• Relative humidity inside the instrument enclosure(rh)
• Surface dew point temperature(dp)

• null(Raw data stream - documentation not supported)

• Surface dew point temperature(dp)
• Relative humidity inside the instrument enclosure(rh)

• Relative humidity inside the instrument enclosure(rh)
• Surface dew point temperature(dp)

• Relative humidity inside the instrument enclosure(rh)
• Surface dew point temperature(dp)

• Surface dew point temperature(dp)
• Relative humidity inside the instrument enclosure(rh)

• Surface dew point temperature(dp)
• Relative humidity inside the instrument enclosure(rh)

• (Development raw data stream - documentation not supported)

• Surface dew point temperature(dp)
• Relative humidity inside the instrument enclosure(rh)

• Surface dew point temperature(dp)
• Relative humidity inside the instrument enclosure(rh)

• (Development data stream - documentation not supported)

• Surface dew point temperature(dp)
• Relative humidity inside the instrument enclosure(rh)

• Relative humidity inside the instrument enclosure(rh)
• Surface dew point temperature(dp)

• (Development data stream - documentation not supported)

• (Development data stream - documentation not supported)

• Relative humidity inside the instrument enclosure(rh)
• Surface dew point temperature(dp)

• null(Raw data stream - documentation not supported)

• (Development data stream - documentation not supported)

• (Development data stream - documentation not supported)

• (Development data stream - documentation not supported)

• Relative humidity inside the instrument enclosure(rh)
• Surface dew point temperature(dp)

• Relative humidity inside the instrument enclosure(rh)
• Surface dew point temperature(dp)

• Surface dew point temperature(dp)
• Relative humidity inside the instrument enclosure(rh)

• Surface dew point temperature(dp)
• Relative humidity inside the instrument enclosure(rh)

• (Development raw data stream - documentation not supported)

• null(Raw data stream - documentation not supported)

• Surface dew point temperature(dp)
• Relative humidity inside the instrument enclosure(rh)

• Relative humidity inside the instrument enclosure(rh)
• Surface dew point temperature(dp)

• Surface dew point temperature(dp)
• Relative humidity inside the instrument enclosure(rh)

• Relative humidity inside the instrument enclosure(rh)
• Surface dew point temperature(dp)

• null(Raw data stream - documentation not supported)

• (Development data stream - documentation not supported)

• Surface dew point temperature(dp)
• Relative humidity inside the instrument enclosure(rh)

• Relative humidity inside the instrument enclosure(rh)
• Surface dew point temperature(dp)

• (Development raw data stream - documentation not supported)

• Relative humidity inside the instrument enclosure(rh)
• Surface dew point temperature(dp)

• Surface dew point temperature(dp)
• Relative humidity inside the instrument enclosure(rh)