SGP/MWR/C1 - IRT removed

There were no IRT data during this period because MWR #10, upon
which the IRT is mounted, was returned to the vendor for upgrades and
replaced with spare MWR #33 which does not have the mounting hardware
or the electronics to accept the IRT.

• Sky Infra-Red Temperature(sky_ir_temp)

• Sky Infra-Red Temperature(sky_ir_temp)

SGP/MWR/C1 - calibration checks

The MWR calibration was checked by a cryogenic (liquid nitrogen) 
blackbody target or (in the case of the Sept 2001 time period)
by pointing the mirror at an internal blackbody target.  The 
brightness temperatures and vap and liq retrievals are not
representative of the sky/atmosphere.

• 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)
• Sky brightness temperature at 31.4 GHz(tbsky31)
• Sky brightness temperature at 23.8 GHz(tbsky23)

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

SGP/MWR/C1 - Time drift

On 9/18/00, I found that the time on the MWR laptop was 1m 21s slow. The Dimension4 
utility had last synchronized the time on 5/5/00. Found that the network DNS settings had been 
disabled. Added the DNS entry for ntp host CF10. Dimension4 synchronized the clock by 
adding 80.91s. The time had drifted at a rate of -0.59s/day.

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

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

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

SGP/MWR/C1 - IRT failure

The IRT was damaged by internal moisture causing sky temperature
measurements that are negatively biased compared to those from
the AERI. IRT#0517 was returned to the manufacturer for repair
and was replaced with spare IRT#1254.

• Sky Infra-Red Temperature(sky_ir_temp)

• Sky Infra-Red Temperature(sky_ir_temp)

SGP/MWR/C1 - Reprocess: IRT insufficiently insulated

The downwelling IRT was insufficiently insulated to maintain an internal 
reference temperature above 0 degrees C. Measurements of sky temperature were 
over-estimated when instrument was below freezing.

Data will be reprocessed, but users can correct data using the following correction 
factor:

If T_reference < -5?C, then

  IRT_corrected = (IRT_original - 32.993K)/0.87238

where T_reference can be estimated with the ambient temperature (e.g.
tkair)

• Sky Infra-Red Temperature(sky_ir_temp)

• Sky Infra-Red Temperature(sky_ir_temp)

SGP/ARSCL/C1 - ARSCL Cloud Bases and Low-level reflectivities

Prior to February 4, 2000, the ARSCL data set incorporated data from the
Beaufort Laser Ceilometer as one of its inputs.  Because of the BLC's
high spatial resolution, this data was often chosen by ARSCL as the
"CloudBaseBestEstimate" for boundary layer clouds. It was subsequently
determined that the BLC cloud base was biased, with the BLC reporting
cloud base heights that are 122 meters too high.

The bias error will be corrected when the entire ARSCL data set is
reprocessed as part of release_4.  (The release version number is included
the the netCDF global comments).   This reprocessing will also include a
small correction the the MMCR near-field reflectivities.  This correction
is less than 1 dB except for hydrometers within 200 meters of the surface.

Thanks to Roger Marchand for helping bracket this problem.

• LASER Cloud Base Height Best Estimate(CloudBaseBestEstimate)

• BLC/VCEIL Clothiaux et al. Algorithm Cloud Base Height(CloudBaseCeilometerCloth)
• MMCR Reflectivity(Reflectivity)
• MMCR Best Estimate of Hydrometeor Reflectivity(ReflectivityBestEstimate)
• BLC/VCEIL Standard Algorithm Cloud Base Height(CloudBaseCeilometerStd)
• LASER Cloud Base Height Best Estimate(CloudBaseBestEstimate)

• BLC/VCEIL Clothiaux et al. Algorithm Cloud Base Height(CloudBaseCeilometerCloth)
• BLC/VCEIL Standard Algorithm Cloud Base Height(CloudBaseCeilometerStd)

SGP/MWR/B4/C1 - LOS cycle skipping

When MWR software version 4.12 was installed at the SGP, it was observed 
that the MWRs at CF and BF4 skip line-of-sight (LOS) observing cycles. In LOS mode, the 
software begins an observing cycle at 0, 20, and 40 seconds after the minute to provide 3 
LOS cycles per minute. If a cycle is delayed so that it takes more than 20 seconds to 
complete, then the next start time is missed, the cycle is skipped, and the data that would 
have been acquired are lost.  

It was demonstrated that the interaction with the IRT at CF slowed the MWR observing cycle 
noticeably and contributed significantly to the LOS cycle skipping. The IRT was removed 
from the MWR on 5 November 2002 and the LOS cycle skipping at the CF was resolved.  The 
IRT data are now available in a new separate datastream: sgpirtC1.a1 (and soon 
sgpirt2sC1.a1).

The BF4 cycle skipping may have resulted from a combination of an additional air 
temperature sensor on this instrument and the use of a fiber optic cable.  However, the cycle 
skipping on this instrument appears to have abated without modifications to the instrument 
configuration.

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

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

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

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

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.

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

• 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)

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

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

SGP/MWR/C1 - Incorrect min and max values

The values of valid_min and valid_max applied to fields tkxc and tknd were incorrect. They 
should be 303 and 333, respectively.

• (tknd)
• Mixer kinetic (physical) temperature(tkxc)

SGP/MWR/C1 - no air temperature signal

When the new blower was upgraded by Radiometrics and reinstalled on the MWR, the air 
temperature sensor failed to properly report. It was determined that the wires carrying the 
signal to the analog board did not conform to the standard expected by the upgraded blower. 
The problem was corrected by changing the wiring.

• Ambient temperature(tkair)

• Ambient temperature(tkair)

SGP/SIRS/C1 - Missing data due to Ice storm and clock problems

Data are missing due to power failures caused by an ice storm
and resulting system/instrument clock problems.

• Instantaneous Downwelling Pyrgeometer Thermopile Voltage, Shaded Pyrgeometer(inst_down_long_hemisp_shaded_tp)
• Instantaneous Downwelling Hemispheric Shortwave, Unshaded Pyranometer Thermopile
  Voltage(inst_global)
• Time offset of tweaks from base_time(time_offset)
• Dummy altitude for Zeb(alt)
• Instantaneous Downwelling Pyrgeometer Dome Thermistor Resistance, Shaded
  Pyrgeometer(inst_down_long_shaded_dome_resist)
• Instantaneous Downwelling Pyrgeometer Case Thermistor Resistance, Shaded
  Pyrgeometer(inst_down_long_shaded_case_resist)
• Instantaneous Uncorrected Downwelling Shortwave Diffuse, Shaded Pyranometer
  Thermopile Voltage(inst_diffuse)
• Instantaneous Upwelling Pyrgeometer Case Thermistor Resistance, Pyrgeometer(inst_up_long_case_resist)
• Instantaneous Upwelling Pyrgeometer Thermopile(inst_up_long_hemisp_tp)
• lat(lat)
• Instantaneous Upwelling Pyrgeometer Dome Thermistor Resistance, Pyrgeometer(inst_up_long_dome_resist)
• Instantaneous Upwelling Shortwave Hemispheric Irradiance, Pyranometer(inst_up_short_hemisp)
• base time(base_time)
• lon(lon)
• Instantaneous Direct Normal Shortwave Irradiance, Pyheliometer Thermopile
  Voltage(inst_direct_normal)

• null(Raw data stream - documentation not supported)

• Measured Downwelling Summed Shortwave Irradiance
  (dirfluxdn_measured+diffluxdn_measured) (ssw)(sswfluxdn_measured)
• Ratio of Measured Downwelling Diffuse Shortwave Irradiance to Measured
  Downwelling Global Shortwave Irradiance (difr)(difratiodn_measured)
• Measured Surface Albedo from Shortwave Irradiance Measurements (alb)(albedosw_measured)
• base time(base_time)
• Time offset of tweaks from base_time(time_offset)
• Difference: difswfluxdn_measured - difswfluxdn_clearskyfit (diffcg)(difswfluxdn_cloudeffect)
• Measured Downwelling Diffuse Shortwave Irradiance (dif)(difswfluxdn_measured)
• Arithmetic Average Cosine of the Solar Zenith Angle Z (CosZ)(solar_cos_z)
• Measured Downwelling Global UVB Irradiance (guvb)(guvbdn_measured)
• Clear-sky Fit Coefficient a to Global UVB Irradiance (UVBa)(coef_clearsky_guvb_a)
• Clear-sky Fit Estimated Downwelling Summed Shortwave Irradiance
  (dirfluxdn_clearskyfit+diffluxdn_clearskyfit) (cssw)(sswfluxdn_clearskyfit)
• Clear-sky Fit Coefficient b to Global UVB Irradiance (UVBb)(coef_clearsky_guvb_b)
• Difference: gswfluxdn_measured - gswfluxdn_clearskyfit (gswfcg)(gswfluxdn_cloudeffect)
• Clear-sky Fit Estimated Downwelling Diffuse Field Shortwave Irradiance (cdif)(difswfluxdn_clearskyfit)
• Clear-sky Fit Estimated Surface Albedo from Shortwave Irradiance Measurements
  (calb)(albedosw_clearskyfit)
• Time Offset from base_time_LST(time_offset_LST)
• Daily Averaged Distance from the Earth to the Sun (auavg)(sun_earth_distance_dailyaverage)
• Arithmetic Average Distance from the Earth to the Sun (au)(sun_earth_distance)
• Date (YYMMDD LST) for which the Coefficients are Applicable(coef_date)
• Ratio of Clear-sky Fit Estimated Downwelling Diffuse Shortwave Irradiance to
  Clear-sky Fit Estimated Downwelling Global Shortwave Irradiance (cdifr)(difratiodn_clearskyfit)
• Clear-sky Fit Estimated Downwelling Direct Shortwave Irradiance (cdir)(dirfluxdn_clearskyfit)
• Difference: sswfluxdn_measured - sswfluxdn_clearskyfit (sswfcg)(sswfluxdn_cloudeffect)
• Clear-sky Detection Flag (clrf)(flag_clearsky_detection)
• Clear-sky Fit Estimated Downwelling Global Shortwave Irradiance (cgsw)(gswfluxdn_clearskyfit)
• Beginning Time of File (LST)(base_time_LST)
• Site Identification(site)
• Measured Downwelling Direct Shortwave Irradiance (dir)(dirfluxdn_measured)
• Dummy altitude for Zeb(alt)
• Clear-sky Fit Coefficient b to Summed Shortwave Irradiance (CSWb)(coef_clearsky_ssw_b)
• Clear-sky Fit Coefficient a to Summed Shortwave Irradiance (CSWa)(coef_clearsky_ssw_a)
• Clear-sky Fit Coefficient a to Global Shortwave Irradiance (CSWa)(coef_clearsky_gsw_a)
• Clear-sky Fit Coefficient b to Global Shortwave Irradiance (CSWb)(coef_clearsky_gsw_b)
• Measured Downwelling Global Shortwave Irradiance (gsw)(gswfluxdn_measured)
• lat(lat)
• Clear-sky Fit Coefficient b to Global minus Summed Shortwave Irradiance
  Difference (SCORb)(coef_clearsky_dsw_b)
• Clear-sky Fit Coefficient a to Global minus Summed Shortwave Irradiance
  Difference (SCORa)(coef_clearsky_dsw_a)
• Clear-sky Fit Coefficient b to Albedo (Albb)(coef_clearsky_albedo_b)
• Clear-sky Fit Coefficient a to Albedo (Alba)(coef_clearsky_albedo_a)
• Clear-sky Offset Coefficient c for Global minus Summed Shortwave Irradiance
  Difference (SCORc)(coef_clearsky_dsw_c)
• Clear-sky Fit Estimated Downwelling Global UVB Irradiance (cguvb)(guvbdn_clearskyfit)
• lon(lon)
• Clear-sky Fit Coefficient b to Diffuse Irradiance to Total Irradiance Ratio
  (DFRb)(coef_clearsky_difratio_b)
• Clear-sky Fit Coefficient a to Diffuse Irradiance to Total Irradiance Ratio
  (DFRa)(coef_clearsky_difratio_a)

• Time Offset from base_time_LST(time_offset_LST)
• Clear-sky Fit Estimated Downwelling Global Shortwave Irradiance (cgsw)(gswfluxdn_clearskyfit)
• Number of 1-minute Cloud Fraction Estimates in the 15-minute Interval (Ncf)(nsamples_cloudfraction)
• Measured Downwelling Diffuse Shortwave Irradiance (dif)(difswfluxdn_measured)
• Measured Downwelling Direct Shortwave Irradiance (dir)(dirfluxdn_measured)
• Difference: sswfluxdn_measured - sswfluxdn_clearskyfit (sswfcg)(sswfluxdn_cloudeffect)
• Measured Downwelling Global UVB Irradiance (guvb)(guvbdn_measured)
• lon(lon)
• Ratio of Clear-sky Fit Estimated Downwelling Diffuse Shortwave Irradiance to
  Clear-sky Fit Estimated Downwelling Global Shortwave Irradiance (cdifr)(difratiodn_clearskyfit)
• Difference: difswfluxdn_measured - difswfluxdn_clearskyfit (diffcg)(difswfluxdn_cloudeffect)
• Measured Downwelling Summed Shortwave Irradiance
  (dirfluxdn_measured+diffluxdn_measured) (ssw)(sswfluxdn_measured)
• Arithmetic Average Cosine of the Solar Zenith Angle Z (CosZ)(solar_cos_z)
• Arithmetic Average Distance from the Earth to the Sun (au)(sun_earth_distance)
• Time offset of tweaks from base_time(time_offset)
• Average over the interval of the standard deviation of difratiodn_measured
  computed using a 3-5 sample window centered at each 1-min sample(difratiodn_measured_stdev)
• Clear-sky Fit Estimated Downwelling Global UVB Irradiance (cguvb)(guvbdn_clearskyfit)
• base time(base_time)
• Difference: gswfluxdn_measured - gswfluxdn_clearskyfit (gswfcg)(gswfluxdn_cloudeffect)
• Site Identification(site)
• Ratio of Measured minus Clear-sky Fit Estimated Downwelling Diffuse Shortwave
  Irradiance to Clear-sky Fit Estimated Downwelling Global Shortwave Irradiance
  (di(difcloudeffect_normalized)
• Dummy altitude for Zeb(alt)
• Fractional Sky Cover(cloudfraction)
• Measured Surface Albedo from Shortwave Irradiance Measurements (alb)(albedosw_measured)
• Number of 1-minute Clear-sky Detections in the 15-minute Interval (Nclr)(nsamples_clearsky_detection)
• Number of 1-minute Clear-sky Fit Downwelling Global Shortwave Irradiance
  Estimates in the 15-minute Interval (Ncsw)(nsamples_gswfluxdn_clearskyfit)
• Ratio of Measured Downwelling Diffuse Shortwave Irradiance to Measured
  Downwelling Global Shortwave Irradiance (difr)(difratiodn_measured)
• Beginning Time of File (LST)(base_time_LST)
• lat(lat)
• Clear-sky Fit Estimated Downwelling Diffuse Field Shortwave Irradiance (cdif)(difswfluxdn_clearskyfit)
• Clear-sky Fit Estimated Surface Albedo from Shortwave Irradiance Measurements
  (calb)(albedosw_clearskyfit)
• Number of 1-minute Measured Downwelling Summed Shortwave Irradiances in the
  15-minute Interval (Nssw)(nsamples_sswfluxdn_measured)
• Measured Downwelling Global Shortwave Irradiance (gsw)(gswfluxdn_measured)
• Clear-sky Fit Estimated Downwelling Summed Shortwave Irradiance
  (dirfluxdn_clearskyfit+diffluxdn_clearskyfit) (cssw)(sswfluxdn_clearskyfit)
• Clear-sky Fit Estimated Downwelling Direct Shortwave Irradiance (cdir)(dirfluxdn_clearskyfit)

• Down-welling unshaded pyranometer voltage(down_short_hemisp)
• Instantaneous Dome Temperature(inst_up_long_dome_temp)
• Instantaneous Case Temperature(inst_up_long_case_temp)
• Upwelling (10 meter) Shortwave Hemispheric Irradiance, Pyranometer, Minima(up_short_hemisp_min)
• Instantaneous Downwelling Pyrgeometer Dome Thermistor Temperature, Shaded
  Pyrgeometer(inst_down_long_shaded_dome_temp)
• Upwelling (10 meter) Longwave Hemispheric Irradiance, Pyrgeometer(up_long_hemisp)
• Shortwave Direct Normal Irradiance, Pyrgeometer, Minima(short_direct_normal_min)
• Downwelling Shortwave Hemispheric Irradiance, Ventilated Pyranometer, Maxima(down_short_hemisp_max)
• Upwelling (10 meter) Shortwave Hemispheric Irradiance, Pyranometer, Standard
  Deviation(up_short_hemisp_std)
• Upwelling (10 meter) Shortwave Hemispheric Irradiance, Pyranometer(up_short_hemisp)
• Downwelling Shortwave Diffuse Hemispheric Irradiance, Ventilated Pyranometer,
  Maxima(down_short_diffuse_hemisp_max)
• Upwelling (10 meter) Longwave Hemispheric Irradiance, Pyrgeometer, Minima(up_long_hemisp_min)
• Upwelling (10 meter) Longwave Hemispheric Irradiance, Pyrgeometer, Standard
  Deviation(up_long_hemisp_std)
• Dummy altitude for Zeb(alt)
• Downwelling Longwave Hemispheric Irradiance, Shaded Pyrgeometer, Maxima(down_long_hemisp_shaded_max)
• Downwelling Shortwave Diffuse Hemispheric Irradiance, Ventilated Pyranometer(down_short_diffuse_hemisp)
• Shortwave Direct Normal Irradiance, Pyrgeometer, Maxima(short_direct_normal_max)
• Downwelling Longwave Hemispheric Net Infrared(down_long_netir)
• Downwelling Shortwave Hemispheric Irradiance, Pyranometer, Standard Deviation(down_short_diffuse_hemisp_std)
• Downwelling Longwave Hemispheric Irradiance, Shaded Pyrgeometer(down_long_hemisp_shaded)
• Downwelling Shortwave Hemispheric Irradiance, Ventilated Pyranometer, Minima(down_short_hemisp_min)
• Upwelling (10 meter) Shortwave Hemispheric Irradiance, Pyranometer, Maxima(up_short_hemisp_max)
• Downwelling Longwave Hemispheric Irradiance, Shaded Pyrgeometer, Standard
  Deviation(down_long_hemisp_shaded_std)
• Instantaneous Downwelling Pyrgeometer Case Thermistor Temperature, Shaded
  Pyrgeometer(inst_down_long_shaded_case_temp)
• Time offset of tweaks from base_time(time_offset)
• lat(lat)
• Upwelling (10 meter) Longwave Hemispheric Irradiance, Pyrgeometer, Maxima(up_long_hemisp_max)
• Downwelling Longwave Hemispheric Irradiance, Shaded Pyrgeometer, Minima(down_long_hemisp_shaded_min)
• Shortwave Direct Normal Irradiance, Pyrgeometer(short_direct_normal)
• Battery Voltage(vBatt)
• lon(lon)
• base time(base_time)
• Downwelling Shortwave Diffuse Hemispheric Irradiance, Ventilated Pyranometer,
  Minima(down_short_diffuse_hemisp_min)
• Shortwave Direct Normal Irradiance, Pyrgeometer, Standard Deviation(short_direct_normal_std)
• Downwelling Shortwave Hemispheric Irradiance, Ventilated Pyranometer, Standard
  Deviation(down_short_hemisp_std)
• Upwelling Longwave Hemispheric Net Infrared(up_long_netir)

• Downwelling Longwave Hemispheric Irradiance, Shaded Pyrgeometer, Minima(down_long_hemisp_shaded_min)
• Upwelling (10 meter) Shortwave Hemispheric Irradiance, Pyranometer, Standard
  Deviation(up_short_hemisp_std)
• Downwelling Shortwave Hemispheric Irradiance, Ventilated Pyranometer, Standard
  Deviation(down_short_hemisp_std)
• Upwelling (10 meter) Longwave Hemispheric Irradiance, Pyrgeometer, Maxima(up_long_hemisp_max)
• Downwelling Shortwave Hemispheric Irradiance, Ventilated Pyranometer, Minima(down_short_hemisp_min)
• Downwelling Shortwave Diffuse Hemispheric Irradiance, Ventilated Pyranometer,
  Maxima(down_short_diffuse_hemisp_max)
• Shortwave Direct Normal Irradiance, Pyrgeometer, Minima(short_direct_normal_min)
• Downwelling Longwave Hemispheric Irradiance, Shaded Pyrgeometer, Standard
  Deviation(down_long_hemisp_shaded_std)
• Downwelling Shortwave Hemispheric Irradiance, Pyranometer, Standard Deviation(down_short_diffuse_hemisp_std)
• base time(base_time)
• Shortwave Direct Normal Irradiance, Pyrgeometer, Maxima(short_direct_normal_max)
• Downwelling Shortwave Diffuse Hemispheric Irradiance, Ventilated Pyranometer(down_short_diffuse_hemisp)
• Upwelling (10 meter) Shortwave Hemispheric Irradiance, Pyranometer, Minima(up_short_hemisp_min)
• Dummy altitude for Zeb(alt)
• Time offset of tweaks from base_time(time_offset)
• Upwelling (10 meter) Shortwave Hemispheric Irradiance, Pyranometer(up_short_hemisp)
• Down-welling unshaded pyranometer voltage(down_short_hemisp)
• lon(lon)
• Downwelling Shortwave Diffuse Hemispheric Irradiance, Ventilated Pyranometer,
  Minima(down_short_diffuse_hemisp_min)
• Battery Voltage(vBatt)
• Shortwave Direct Normal Irradiance, Pyrgeometer(short_direct_normal)
• Upwelling (10 meter) Longwave Hemispheric Irradiance, Pyrgeometer, Standard
  Deviation(up_long_hemisp_std)
• Downwelling Shortwave Hemispheric Irradiance, Ventilated Pyranometer, Maxima(down_short_hemisp_max)
• Upwelling (10 meter) Longwave Hemispheric Irradiance, Pyrgeometer(up_long_hemisp)
• lat(lat)
• Downwelling Longwave Hemispheric Irradiance, Shaded Pyrgeometer(down_long_hemisp_shaded)
• Upwelling (10 meter) Shortwave Hemispheric Irradiance, Pyranometer, Maxima(up_short_hemisp_max)
• Upwelling (10 meter) Longwave Hemispheric Irradiance, Pyrgeometer, Minima(up_long_hemisp_min)
• Downwelling Longwave Hemispheric Irradiance, Shaded Pyrgeometer, Maxima(down_long_hemisp_shaded_max)
• Shortwave Direct Normal Irradiance, Pyrgeometer, Standard Deviation(short_direct_normal_std)

• Shortwave Direct Normal Irradiance, Pyrgeometer, Standard Deviation(short_direct_normal_std)
• Downwelling Shortwave Hemispheric Irradiance, Ventilated Pyranometer, Maxima(down_short_hemisp_max)
• Upwelling Longwave Hemispheric Net Infrared(up_long_netir)
• Downwelling Longwave Hemispheric Net Infrared(down_long_netir)
• Instantaneous Downwelling Pyrgeometer Case Thermistor Temperature, Shaded
  Pyrgeometer(inst_down_long_shaded_case_temp)
• Upwelling (10 meter) Shortwave Hemispheric Irradiance, Pyranometer(up_short_hemisp)
• Battery Voltage(vBatt)
• Downwelling Shortwave Diffuse Hemispheric Irradiance, Ventilated Pyranometer(down_short_diffuse_hemisp)
• Upwelling (10 meter) Longwave Hemispheric Irradiance, Pyrgeometer, Standard
  Deviation(up_long_hemisp_std)
• Shortwave Direct Normal Irradiance, Pyrgeometer, Minima(short_direct_normal_min)
• Downwelling Shortwave Hemispheric Irradiance, Ventilated Pyranometer, Standard
  Deviation(down_short_hemisp_std)
• Downwelling Longwave Hemispheric Irradiance, Shaded Pyrgeometer, Maxima(down_long_hemisp_shaded_max)
• Shortwave Direct Normal Irradiance, Pyrgeometer(short_direct_normal)
• Instantaneous Dome Temperature(inst_up_long_dome_temp)
• Upwelling (10 meter) Longwave Hemispheric Irradiance, Pyrgeometer(up_long_hemisp)
• base time(base_time)
• Downwelling Shortwave Diffuse Hemispheric Irradiance, Ventilated Pyranometer,
  Maxima(down_short_diffuse_hemisp_max)
• Upwelling (10 meter) Shortwave Hemispheric Irradiance, Pyranometer, Maxima(up_short_hemisp_max)
• Down-welling unshaded pyranometer voltage(down_short_hemisp)
• Downwelling Shortwave Hemispheric Irradiance, Pyranometer, Standard Deviation(down_short_diffuse_hemisp_std)
• Upwelling (10 meter) Longwave Hemispheric Irradiance, Pyrgeometer, Minima(up_long_hemisp_min)
• Instantaneous Case Temperature(inst_up_long_case_temp)
• Time offset of tweaks from base_time(time_offset)
• Downwelling Longwave Hemispheric Irradiance, Shaded Pyrgeometer(down_long_hemisp_shaded)
• Downwelling Shortwave Hemispheric Irradiance, Ventilated Pyranometer, Minima(down_short_hemisp_min)
• lat(lat)
• Upwelling (10 meter) Shortwave Hemispheric Irradiance, Pyranometer, Standard
  Deviation(up_short_hemisp_std)
• lon(lon)
• Downwelling Shortwave Diffuse Hemispheric Irradiance, Ventilated Pyranometer,
  Minima(down_short_diffuse_hemisp_min)
• Shortwave Direct Normal Irradiance, Pyrgeometer, Maxima(short_direct_normal_max)
• Downwelling Longwave Hemispheric Irradiance, Shaded Pyrgeometer, Minima(down_long_hemisp_shaded_min)
• Downwelling Longwave Hemispheric Irradiance, Shaded Pyrgeometer, Standard
  Deviation(down_long_hemisp_shaded_std)
• Upwelling (10 meter) Shortwave Hemispheric Irradiance, Pyranometer, Minima(up_short_hemisp_min)
• Instantaneous Downwelling Pyrgeometer Dome Thermistor Temperature, Shaded
  Pyrgeometer(inst_down_long_shaded_dome_temp)
• Upwelling (10 meter) Longwave Hemispheric Irradiance, Pyrgeometer, Maxima(up_long_hemisp_max)
• Dummy altitude for Zeb(alt)

SGP/MWR/C1 - Wet window flag "on" more frequently than expected

The wet window flag was set "on" more frequently than expected during the time periods 
specified.  This indicates the heater has been running more than necessary.  In most 
instances the moisture sensitivity was adjusted at the end of these periods.

• MWR column precipitable water vapor(vap)
• Averaged total liquid water along LOS path(liq)
• Sky brightness temperature at 31.4 GHz(tbsky31)
• Sky brightness temperature at 23.8 GHz(tbsky23)
• Water on Teflon window (1=WET, 0=DRY)(wet_window)

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

SGP/MWR/C1 - spare instrument

The spare MWR, S.N. 04, was installed while the production instrument, S.N. 10, was 
returned to the manufacturer for upgrades.

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

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

SGP/SIRS/C1 - Reprocess: Adjust Direct Normal Irradiance

Direct normal broadband shortwave irradiance measured by NIP s/n 30722E6 was found to have 
a 0.62%% negative bias when compared in-situ with absolute cavity radiometer 
measurements taken on August 21, 2000.  The estimated measurement uncertainty of the calibration of 
NIP s/n 30722E6 on July 18, 2000 was -2.6% to +4.8%.  

Data from NIP s/n 30722E6 can be adjusted according to the in-situ comparisons to reduce 
the apparent measurement bias.

• null(Raw data stream - documentation not supported)

• null(Raw data stream - documentation not supported)

• Measured Downwelling Direct Shortwave Irradiance (dir)(dirfluxdn_measured)

• Measured Downwelling Direct Shortwave Irradiance (dir)(dirfluxdn_measured)

SGP/SIRS/C1 - SWFANAL Data description error

The long name attribute for the cloud effect fields incorrectly
defines the cloud effect to be the difference between the 
clearskyfit and measured values:

"Difference: ***fluxdn_clearskyfit - ***fluxdn_measured (***fcg)" ;

The cloud effects are correctly calculated by subtracting the 
irradiance calculated in the clear sky fit from the measured 
irradiance.

"Difference: ***fluxdn_measured - ***fluxdn_clearskyfit (***fcg)" ;

NOTE: this is just a documentation error.  The data are correctly
calculated.

• Difference: difswfluxdn_measured - difswfluxdn_clearskyfit (diffcg)(difswfluxdn_cloudeffect)
• Difference: sswfluxdn_measured - sswfluxdn_clearskyfit (sswfcg)(sswfluxdn_cloudeffect)
• Difference: gswfluxdn_measured - gswfluxdn_clearskyfit (gswfcg)(gswfluxdn_cloudeffect)

• Difference: gswfluxdn_measured - gswfluxdn_clearskyfit (gswfcg)(gswfluxdn_cloudeffect)
• Difference: sswfluxdn_measured - sswfluxdn_clearskyfit (sswfcg)(sswfluxdn_cloudeffect)
• Difference: difswfluxdn_measured - difswfluxdn_clearskyfit (diffcg)(difswfluxdn_cloudeffect)

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.

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

• 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)

• 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)

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

SGP/MWR/C1 - New software version (4.15) installed

A problem began with the installation of MWR.EXE version 4.12 in July 2002. The software 
had been upgraded from a "DOS" to a "Windows"-compiled program to address an earlier 
problem.  The software upgrade corrected the earlier problem but introduced a new one that 
caused line-of-sight observing cycles to be skipped, a 15% reduction in the number of tip 
curves, and saturation of CPU usage. Software versions 4.13 and 4.14 also produced these 
problems.

The new MWR software, version 4.15, was installed on 08/04/2005. As a consequence of this 
upgrade, the tip curve frequency increased. The tip cycle time decreased from ~60s to 
~50s.

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

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

SGP/MWR/C1 - Missing data

Data are missing and unrecoverable.

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

SGP/MWR/C1 - IRT rain lid removal

The IR thermometer (or IRT) was deployed at the SGP central facility in
January 1994 with an automatic mechanism which closed a protective lid
over the zenith-viewing lens when a moisture detector indicated
condensation or precipitation.

Since that time the 120 VAC-to-12 VAC transformer in the lid mechanism
has failed 5 times with an average downtime of two weeks.  In addition,
the collar by which the (normally open) lid is attached to the lens
barrel of the IRT has made it difficult for site operations personnel
to observe the condition of the IRT lens.  As a result, dirt and
insects have been able to accumulate on the lens.  This has resulted in
long periods of invalid data.

To alleviate these problems the lid mechanism was removed from service
on 16 August at my recommendation.

It is anticipated that condensation and precipitation will result in
invalid data.  However, these events should be readily detectable
because the observed IR temperature will closely match the ambient
temperature (e.g. the temperature of the moisture on the lens) which is
usually much greater than the sky or cloud base temperature normally
measured.  I believe that this will not result in a large increase in
invalid data because these data would have been invalid anyway when the
lid was closed.  (This situation is now the same as for the other 
radiometers at the site.)

In addition, removing the attaching collar from the lens barrel will
prevent insects from nesting in it, and will permit site operations
personnel easy access to the lens so that they may more easily maintain
it in a clean condition.

A summary of the quality of the IR thermometer data in general,
including notes on the performance of the protective lid, follows:

JANUARY 1994
 19-JAN:  Operational.  No IR data collected.

FEBRUARY 1994
  2-FEB:  Failure of lid reported.  Transformer burned out.
 15-FEB:  IRT returned to service.    
 24-FEB:  Valid data begin.

MARCH 1994
  3-MAR:  Failure of lid reported. Transformer burned out.
  8-MAR:  IRT returned to service.
  8-MAR:  Cable problems reported.
 17-MAR:  Cable problems resolved.  IRT returned to service.
 17-27-MAR:  Comparison with AERI indicates IRT 1-10 deg C higher; 
          increasing error with decreasing temperatures.  Probably  
          due to dirt/debris on lens.  Also, IRT calibration not valid
          below -50 deg C (223 K).
 21-MAR:  Problems with O-ring on lid sticking reported/repaired.

APRIL 1994
 Data values below -50 deg C (223 K) not valid - below range of 
 calibration.  Otherwise data within 2-3 degrees of AERI.
 24-APR: Large (10-20 Deg C) offset between IRT and AERI develops.

MAY 1994
  7-MAY: Mentor visits site, observes spider's nest and dead insects
         inside collar attaching lid to lens barrel in optical path of
         instrument. Probably the source of the offset between IRT and
         AERI during late and April.
  9-MAY: Insects removed, lens cleaned by site operations personnel.
         Agreement between IRT and AERI within 1 deg C.
 23-MAY: Failure of lid reported.  Transformer burned out.

JUNE 1994
 22-JUN: Rebuilt/redesigned lid mechanism put in service; data collection
         computer fails same day.

JULY 1994
 11-JUL: Computer returned to service.  
         Agreement between IRT and AERI within 1 deg C.
 22-JUL: Failure of lid reported.  Transformer burned out.

AUGUST 1994
  3-AUG: IRT returned to service.
 12-AUG: Failure of lid reported.  Transformer burned out.
 16-AUG: Lid mechanism abandoned.

• Sky Infra-Red Temperature(sky_ir_temp)

• Sky Infra-Red Temperature(sky_ir_temp)

SGP/MWR/C1 - Data dropouts due to serial comm problems

Conflicts between the drop shipper program and the MWR operation program resulted in 
serial communication problems which ultimately manifested as spikes and dropouts in the data.

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

• 23.8 GHz blackbody+noise injection signal(bbn23)
• Mixer kinetic (physical) temperature(tkxc)
• 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 23.8 GHz(tbsky23)
• Temperature correction coefficient at 31.4 GHz(tc31)
• Averaged total liquid water along LOS path(liq)
• Blackbody kinetic temperature(tkbb)
• 31.4 GHz sky signal(sky31)
• Temperature correction coefficient at 23.8 GHz(tc23)
• Time offset of tweaks from base_time(time_offset)
• 31.4 GHz blackbody(bb31)
• MWR column precipitable water vapor(vap)
• 31.4 GHz blac2body+noise injection signal(bbn31)
• Ambient temperature(tkair)
• 23.8 GHz Blackbody signal(bb23)
• Noise injection temp at nominal temperature at 23.8 GHz(tnd_nom23)
• 23.8 GHz sky signal(sky23)
• Sky brightness temperature at 31.4 GHz(tbsky31)
• Noise injection temp at 23.8 GHz adjusted to tkbb(tnd23)
• Sky Infra-Red Temperature(sky_ir_temp)
• base time(base_time)
• Noise injection temp at 31.4 GHz adjusted to tkbb(tnd31)
• (tknd)

SGP/MWR/C1 - IR thermometer calibration check

Mentor used an Everest model 1000 ambient temperature target 
(emis.=0.98) to check the calibration of the Heiman IR pyrometer
(IR thermometer).  Data collected during this period will be
anomalous due to the modifications of the instrument settings
required to facilitate the calibration.

The emissivity of the instrument was changed to match the target;
units were changed to deg C (from K) to match the target LCD units;
integration time on the instrument was changed to 3 seconds (from 1
second).

Centered the target on the instrument lens and allowed it to rest
on the lens barrel so that it filled the field of view of the
instrument. Both the instrument LCD and target LCD indicated 16.7
deg C.

Noted that although the lens appeared clean, there was some liquid
water around the edge which formed a meniscus with the inside of
the lens barrel. Wiped this away with a clean, lint-free cotton
cloth.

Replaced the target on the lens barrel; both instrument and target
then indicated 17.1 deg C.

Reset the instrument emissivity (=1.0), the units (kelvins) and
the integration time (=1 sec).

The IRT was deployed in December 1993.  Its calibration appears to
have been stable since deployment.  Liquid water around the edge of
the lens appears to be out of the field of view and does not appear
to affect the data.

• Sky Infra-Red Temperature(sky_ir_temp)

• Sky Infra-Red Temperature(sky_ir_temp)

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.

• 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)

• 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)
• Sky brightness temperature at 31.4 GHz(tbsky31)
• Sky brightness temperature at 23.8 GHz(tbsky23)

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

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.

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

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

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

SGP/MWR/C1 - IRT lens replaced

The lens of the uplooking "IR thermometer" (a 10 micrometer pyrometer)
was replaced on 28 October 1996 at 16:18 GMT.  At the time the sky was
heavily overcast (0.1-0.5 mm liquid water path, IR temperature =
281-285 K) with about 4 cm integrated water vapor.  A comparison was
carried out against the Atmospheric Emitted Radiance Interferometer
(AERI) both prior to and subsequent to the lens change.  The statistics
of the differences (IRT-AERI) are as follows:

         Mean (K)  Std Dev (K)   No.
Before:    0.64      0.24       122
After:     0.35      0.20        89

In addition, the downward step change in the time series plot of the
temperature difference (IRT-AERI) at the time of the lens replacement
is obvious.

This suggests, but is not conclusive evidence, that the primary cause
of the differences between the IRT and AERI reported previously
(PIF no. P960809.2) may have been the weather-worn lens.  However,
as this instrument has not been calibrated since it was deployed in
December 1993, there may also be calibration drift to contend with.

Arrangements are being pursued with NREL to check the calibration of
this instrument.

It is preferable to carry out the IRT vs AERI comparison for clear sky
conditions to be certain that both instruments are observing the same
scene at the moment when they make sky measurements.  However, it is
not possible at this time of the year to carry out a clear sky
comparison because the integrated water vapor is generally less than
2.0 cm which means that the IR temperature is less than 223 K, the
lower limit of the D/A converter on the IRT.

On the positive side, the AERI and the IRT are within 10 m of each
other and have similar fields of view (about 2 degrees) so their
scenes should be comparable for clear or cloudy skies.

• Sky Infra-Red Temperature(sky_ir_temp)

• Sky Infra-Red Temperature(sky_ir_temp)

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.

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

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

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

• 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)

• 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)

• 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)

• 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)

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

• 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)

• 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)

SGP/MWR/C1 - IRT Calibration check

IRT was out of service for calibration check.  MWR was powered
down on 96/12/03 1937-1949 to remove IRT and on 96/12/12 1848-1920
to re-install IRT.

The following is from the NREL Metrology Laboratory test report of 12/10/97:

Temperature     Nominal Value     Measured Value
-----------     -------------     --------------
  0 C             273.2 K           274.1 K
 10               283.2             283.6
 20               293.2             293.6
 30               303.2             303.2
 40               313.2             313.2

In the range tested, the temperature difference is within the
resolution of the instrument, so the IRT was not adjusted and
the calibration factor was not changed.

• Sky Infra-Red Temperature(sky_ir_temp)

• Sky Infra-Red Temperature(sky_ir_temp)

SGP/MWR/C1 - IRT Calibration

Comparison of the uplooking IRT with AERI for 5 May 1997 during a time
when the 9-11 micrometer sky temperature was in the range 220-228 K,
according to AERI, the IRT indicated approximately 3 K higher.  This is
outside of the specified uncertainty in the IRT and indicates that the
calibration needs to be revised.

• Sky Infra-Red Temperature(sky_ir_temp)

• Sky Infra-Red Temperature(sky_ir_temp)

SGP/MWR/C1 - IRT offline

The IRT was removed from the MWR to perform a comparison/calibration check prior to the 
Integrated IOP.

• Sky Infra-Red Temperature(sky_ir_temp)

• Sky Infra-Red Temperature(sky_ir_temp)

SGP/MWR/C1 - IRT lens replaced

During my recent trip to the SGP I noticed that the IRT was reading
too high (about 250 K for clear sky with less than 2 cm PWV).  The
anti-reflective coating on the lens appeared to have deteriorated
significantly.  Because I observed no change in the measurements
after cleaning the lens, I replaced it with the original lens which
had been saved as a spare.

The measured sky temperature fell to 232 K, which appeared more reasonable.

The next morning I realized that I had forgotten to clean the lens
after replacing it.  After cleaning the IR temperature fell from 219
to 213 K with about 1.2 cm PWV.  This appeared to be in agreement
with Martin Platt's radiometer which measures the same passband
(10 micrometers.)

Upon returning to Ames, I compared the IRT with AERI for April 1998.
It appears that at least as far back as 1 April the IRT data are bad.

• Sky Infra-Red Temperature(sky_ir_temp)

• Sky Infra-Red Temperature(sky_ir_temp)

SGP/MWR/C1 - Erroneous internal temperature

After the new internal temperature sensor was installed it was discovered
that the scaling resistor was incorrect.  (The 24.9 kohm 0.1% resistor
had accidently been replaced with a 24.0 kohm resistor when the analog
board was repaired by the manufacturer several years ago.)  A resistor
having the correct value was installed 981112.

• Ambient temperature(tkair)

• Ambient temperature(tkair)

• Ambient temperature(tkair)

SGP/MWR/B1/B4/B6/C1 - software change

The MWR operating software was changed on 12 October 1998 to provide additional 
functionality as described below. This change affects the format of the raw and ingested data. 
   
NEW FEATURES
1. Faster sampling rate
   
Standard line-of-sight (LOS) observations can now be acquired at 15-second intervals vs. 
20-second intervals previously. (The standard LOS cycle is comprised of one sky sample per 
blackbody sample and gain update.)
   
2. More flexible sampling strategy
   
Multiple sky observations can be acquired during a LOS cycle, up to 1024 per gain update. 
This permits sky samples to be acquired at intervals of 2.67 seconds for improved 
temporal resolution of cloud liquid water variations and better coordination with the millimeter 
cloud radar during IOPs.
   
3. Separation of zenith LOS observations from TIP data
   
When the radiometer is in TIP mode, the zenith LOS observations are now extracted, the PWV 
and LWP computed and reported separately in the output file. This eliminates the periods 
of missing LOS data during calibration checks/updates.
   
4. Automatic self-calibration
   
The software now permits the calibration to be updated at specified intervals or 
continuously. In the first case, LOS mode is automatically changed to TIP mode at user-specified 
intervals or whenever clear sky conditions occur, the tip data reduced, the calibration 
updated ,and the radiometer returned to LOS mode without operator intervention. In the 
second case, the radiometer is continuously is TIP mode until changed by the operator.
   
5. Graphical user display
   
The graphical display is comprised of a status display, a message display, a temperature 
plot, a plot of the retrieved PWV and LWP, and (in TIP mode) a plot of the latest tip 
curves.

Editor's Note: The SGP.C1 data were reprocessed in 2004 and enhancement #3 described above 
was applied to the data prior to Oct 1998.  The SGP.BF data are queued for reprocessing 
as well.

• Ambient temperature(tkair)
• Noise injection temp at 23.8 GHz adjusted to tkbb(tnd23)
• (tknd)
• Noise injection temp at 31.4 GHz adjusted to tkbb(tnd31)

• Noise injection temp at 23.8 GHz adjusted to tkbb(tnd23)
• Noise injection temp at 31.4 GHz adjusted to tkbb(tnd31)
• (tknd)
• Ambient temperature(tkair)

• Noise injection temp at 23.8 GHz derived from this tip(tnd23I)
• Noise injection temp at 31.4 GHz derived from this tip(tnd31I)

• (tknd)
• Ambient temperature(tkair)
• Noise injection temp at 31.4 GHz adjusted to tkbb(tnd31)
• Noise injection temp at 23.8 GHz adjusted to tkbb(tnd23)

• Noise injection temp at 31.4 GHz adjusted to tkbb(tnd31)
• (tknd)
• Noise injection temp at 23.8 GHz adjusted to tkbb(tnd23)
• Ambient temperature(tkair)

• Noise injection temp at 31.4 GHz adjusted to tkbb(tnd31)
• Ambient temperature(tkair)
• (tknd)
• Noise injection temp at 23.8 GHz adjusted to tkbb(tnd23)

• Noise injection temp at 23.8 GHz derived from this tip(tnd23I)
• Noise injection temp at 31.4 GHz derived from this tip(tnd31I)

• Noise injection temp at 23.8 GHz derived from this tip(tnd23I)
• Noise injection temp at 31.4 GHz derived from this tip(tnd31I)

• (tknd)
• Noise injection temp at 31.4 GHz adjusted to tkbb(tnd31)
• Noise injection temp at 23.8 GHz adjusted to tkbb(tnd23)
• Ambient temperature(tkair)

• Ambient temperature(tkair)
• Noise injection temp at 23.8 GHz adjusted to tkbb(tnd23)
• Noise injection temp at 31.4 GHz adjusted to tkbb(tnd31)
• (tknd)

• Noise injection temp at 31.4 GHz adjusted to tkbb(tnd31)
• Ambient temperature(tkair)
• (tknd)
• Noise injection temp at 23.8 GHz adjusted to tkbb(tnd23)

SGP/MWR/B1/B4/B5/B6/C1 - software upgrade (version 3.27)

At 00:00 GMT on 7 January version 3.27 of the MWR operating program was installed and made 
operational at the SGP central facility (C1).  No problems were noted over the next few 
days and the boundary facility MWRs (B1, B4, B5, B6) were upgraded at 20:00 GMT on 11 
January.  This version includes a beam width correction I developed as well as providing the 
capability to automatically level the elevation mirror (that is, to automatically detect 
and correct offsets in the elevation angle stepper motor position.)

On 12 January I discovered that the '486-based MWR computers at B1, B4 and B6 were not 
executing the system command to move and rename the data files so that the ARM data system 
could retrieve them.  Reducing the length of the storage arrays in the auto-leveling 
feature from 1000 to 250 resolved the problem.  This results in the auto-leveling being based 
on only 4 hours of clear sky data rather than 16 hours at B5 and C1.  This version of the 
program is 3.28. Version 3.27 (running at B5 and C1) can be installed if and when these 
computers are upgraded to Pentium-class machines.

The improvement in the quality of the tip curves resulting from the auto-leveling has been 
dramatic: differences in the brightness temperatures at 3 airmasses (19.5 and 160.5 
degrees) have been reduced from +/- 5 K to +/- 0.5 K.  The goodness-of-fit coefficient for 
the tip curves has improved from about 0.995 to over 0.998.  In order to take full 
advantage of this improvement to detect and reject cloudy tip curves, the minimum value of the 
goodness-of-fit coefficient for a valid tip curve has been increased from 0.995 to 0.998.

Editor's Note: The SGP.C1 data were reprocessed in 2004 to produce a common DOD for all 
time.  The 1996-1998 data reprocessing included beam width and mirror-leveling corrections, 
but the data prior to that range did not have these corrections applied.

• 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)

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

• 23.8 GHz sky signal(23tipsky)
• 31.4 GHz sky signal(31tipsky)

• 31.4 GHz sky signal(31tipsky)
• 23.8 GHz sky signal(23tipsky)

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

• 31.4 GHz sky signal(31tipsky)
• 23.8 GHz sky signal(23tipsky)

• 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)

• 31.4 GHz sky signal(31tipsky)
• 23.8 GHz sky signal(23tipsky)

• 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)
• 31.4 GHz sky brightness temperature(31tbsky)

SGP/MWR/B1/B4/B6 - Reprocess: Data Ingest Problem

The first version of the new ingest produced incorrect values of variables tbsky23 and 
ir_temp and global attribute elevation_angle. 
In evaluating this file, I found that tbsky23 is actually tnd31, ir_temp is 
noise_injection_temp_31, and elevation is '1079410688 deg' instead of 90. All other variables and 
global attributes are ok. 

Note, the SGP.C1 data were also originally affected by this problem, but they were 
subsequently reprocessed.  This DQR will be removed when the SGP.BF data have also been 
reprocessed.

• IR Brightness Temperature(ir_temp)
• Sky brightness temperature at 23.8 GHz(tbsky23)

• Sky brightness temperature at 23.8 GHz(tbsky23)
• IR Brightness Temperature(ir_temp)

• IR Brightness Temperature(ir_temp)
• Sky brightness temperature at 23.8 GHz(tbsky23)

• Sky brightness temperature at 23.8 GHz(tbsky23)
• IR Brightness Temperature(ir_temp)

• Sky brightness temperature at 23.8 GHz(tbsky23)
• IR Brightness Temperature(ir_temp)

• IR Brightness Temperature(ir_temp)
• Sky brightness temperature at 23.8 GHz(tbsky23)

SGP/MWR/B1/B4/B5/B6 - data file split at 23:59

A problem with the MWR operating software has been corrected.  However, several files were 
generated that contain one record of data collected at midnight but labeled with the 
previous day's date.

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

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

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

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

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

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

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

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

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

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

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

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