TWP/SMET/C1 - Reprocess: Skewed wind direction 1 data

Wind direction 1 data is incorrect. 
Manus SMET wind direction for Wind-1 (upper unit) was apparently skewed
from its original position as a result of checking direction calibration. 

As near as we can tell the position of the sensor was rotated clockwise
Somewhere in the range of 45-90 degrees, most likely in steps 22.5 degrees.

Data comparison performed on 3-2-00, using a small amount of data from 
this instrument.

• Raw data stream - documentation not supported

• wind1_dir_sd
• Wind #1 direction vector average(wind1_dir_vec_avg)
• Wind #1 speed vector average(wind1_spd_vec_avg)

• Wind #1 speed vector average(wind1_spd_vec_avg)
• wind1_dir_sd
• Wind #1 direction vector average(wind1_dir_vec_avg)

TWP/SMET/C1 - Wind Direction alignment method

During RESET10 we discovered a problem with wind direction from WIND1 (upper
anemometer).  During RESET8, WIND1 was corrected by rotating the alignment
ring instead of the anemometer.  This resulted in a better agreement between
the 2 anemometers, but is not the correct way to align an anemometer. The
alignment ring was readjusted for true north and the anemometer reset in
the proper slot (the original problem).

• Raw data stream - documentation not supported

• wind1_dir_sd
• Wind #1 direction vector average(wind1_dir_vec_avg)
• Wind #1 speed vector average(wind1_spd_vec_avg)

• Wind #1 speed vector average(wind1_spd_vec_avg)
• wind1_dir_sd
• Wind #1 direction vector average(wind1_dir_vec_avg)

TWP/SMET/C1 - Incorrect calibration for ARCS1 Wind speed

On 23 OCT 99, during Reset 8, an incorrect slope of was entered for the 
upper, windspeed1, wind speed sensor resulting in a 1% overestimate of
the wind speed.  The correct calibration was entered on 1 APR 2000 during
RESET 10.

• Raw data stream - documentation not supported

• wind1_spd_sd
• Wind #1 speed arithmetic average(wind1_spd_arith_avg)
• Wind #1 speed maximum gust(wind1_spd_max_gust)
• Wind #1 speed vector average(wind1_spd_vec_avg)
• Wind #1 speed maximum(wind1_spd_max)
• Wind #1 speed minimum(wind1_spd_min)

• Wind #1 speed maximum gust(wind1_spd_max_gust)
• Wind #1 speed vector average(wind1_spd_vec_avg)
• Wind #1 speed arithmetic average(wind1_spd_arith_avg)
• wind1_spd_sd
• Wind #1 speed minimum(wind1_spd_min)
• Wind #1 speed maximum(wind1_spd_max)

• Raw data stream - documentation not supported

TWP/C1 - Incorrect elevation reported in Manus Data

(From Bill Clements) We have been using 6m MSL as the station
elevation of Momote (Manus).  This was based on information
posted near the station barometer in the Momote Weather Service
Office.  It turns out that the official WMO station elevation
for Momote is 4m MSL and the upper air elevation is 5m MSL.

All Manus instruments except the sonde station are at 4m MSL.
The sonde launching station is at 5m MSL.

• alt

TWP/MWR/C1 - Rain on window

The data is subject to contamination due to rain on the sensor window
and should be used with caution because the heater/blower assembly that
prevents water from accumulating on the sensor's teflon window was out
of commission.

• r23
• wet_window
• r31
• bbn23
• bb31
• tipsky31
• bb23
• tipsky23
• tipn
• bbn31
• Temperature, brightness, longwave(ir_temp)

• wet_window
• Total liquid water along LOS path(liq)
• 31.4 GHz sky brightness temperature(tbsky31)
• Temperature, brightness, longwave(ir_temp)
• Total water vapor along LOS path(vap)
• 23.8 GHz sky brightness temperature(tbsky23)

TWP/SMET/C1 - Elevated relative humidity

The relative humidity has been exceeding 100% with unusual regularity.
The most dramatic case occured on December 31 when the RH exceeded 100%
for 18 hours and exceeded 103.5% for 6 hours with a maximum value of
103.8%.  A PIF was submitted to propose changing this sensor. This change
occurred on August 12, 1999.

• Relative humidity mean(relh_mean)
• Relative humidity minimum(relh_min)
• relh_sd
• Relative humidity maximum(relh_max)

• Relative humidity mean(relh_mean)
• Relative humidity minimum(relh_min)
• Relative humidity maximum(relh_max)
• relh_sd

TWP/SMET/C1 - Wind speed calibration errors

Wind speed calibration factors were reversed between wind speed sensors 1 (upper) and 2 
(lower). Results in less than 1% error, but correction factors may be used.

To correct wind speed #1 (upper) add 0.03 m/s.
To correct wind speed #2 (lower) subtract 0.03 m/s.

• lo_spd_max
• up_spd_max
• lo_spd_vec_avg
• lo_spd_min
• up_spd_sd
• up_spd_arith_avg
• up_spd_min
• lo_spd_arith_avg
• up_spd_vec_avg
• lo_spd_sd

• Wind #2 speed arithmetic average(wind2_spd_arith_avg)
• Wind #1 speed maximum gust(wind1_spd_max_gust)
• Wind #1 speed vector average(wind1_spd_vec_avg)
• Wind #2 speed maximum(wind2_spd_max)
• Wind #1 speed arithmetic average(wind1_spd_arith_avg)
• Wind #2 speed minimum(wind2_spd_min)
• Wind #2 speed vector average(wind2_spd_vec_avg)
• wind1_spd_sd
• Wind #1 speed minimum(wind1_spd_min)
• wind2_spd_sd
• Wind #1 speed maximum(wind1_spd_max)
• Wind #2 speed maximum gust(wind2_spd_max_gust)

TWP/C1 - Incorrect elevation reported in Manus Data

(From Bill Clements) We have been using 6m MSL as the station
elevation of Momote (Manus).  This was based on information
posted near the station barometer in the Momote Weather Service
Office.  It turns out that the official WMO station elevation
for Momote is 4m MSL and the upper air elevation is 5m MSL.

All Manus instruments except the sonde station are at 4m MSL.
The sonde launching station is at 5m MSL.

• alt

• alt

• alt

• alt

• alt

TWP/C1 - Incorrect elevation reported in Manus Data

(From Bill Clements) We have been using 6m MSL as the station
elevation of Momote (Manus).  This was based on information
posted near the station barometer in the Momote Weather Service
Office.  It turns out that the official WMO station elevation
for Momote is 4m MSL and the upper air elevation is 5m MSL.

All Manus instruments except the sonde station are at 4m MSL.
The sonde launching station is at 5m MSL.

• alt

TWP/MWR/C1 - wrong azimuth

The MWR was initially installed at an azimuth angle defined as 180 degrees but the value 
in the configuration file was not changed from the default of 0 degrees. In examining 
photos taken during the installation of the AWS tower, I noticed that the MWR was rotated 
opposite the normal orientation. The value in the configuration file was changed to reflect 
the actual azimuth of the instrument.

• actaz

TWP/SMET/C1 - Negative rainfall rates

Due to limitations of the Zeno dataloggers all voltage measurements
from the optical rain gauge (ORG) were converted to rainfall rates. 
This resulted in negative values for rain rates.  Any value below 0.10 mm/hr should be 
considered to be 0 mm/hr.  New dataloggers 
alleviated this problem.  New loggers were installed 03/09/2004 @ 2243 GMT.

• Precipitation minimum(precip_min)
• Precipitation maximum(precip_max)
• precip_sd
• Precipitation mean(precip_mean)

TWP/MWR/C1 - Software Change

The MWR operating software was changed on 27 February 1999 to provide additional
functionality as described below.
   
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.

• actel
• tkair
• Temperature, Sky Infra-Red(sky_ir_temp)
• lon
• actaz
• bb31
• tnd_nom23
• sky23
• bbn23
• tkxc
• tnd31
• Temperature, brightness, longwave(ir_temp)
• sky31
• tc23
• tkbb
• time_offset
• 23.8 GHz sky brightness temperature(tbsky23)
• wet_window
• bbn31
• bb23
• tnd_nom31
• Total liquid water along LOS path(liq)
• 31.4 GHz sky brightness temperature(tbsky31)
• tc31
• tnd23
• lat
• tknd
• base_time
• alt
• Total water vapor along LOS path(vap)

TWP/MWR/C1 - software upgrade (version 3.29)

The MWR operating program was upgraded to version 3.29 on 15 March 1999. This version 
included a beam width correction as well as provided the capability to automatically level 
the elevation mirror (that is, to automatically detect and correct offsets in the elevation 
angle stepper motor position.)
   
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. 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.

• 31.4 GHz sky brightness temperature(tbsky31)
• Total liquid water along LOS path(liq)
• 23.8 GHz sky brightness temperature(tbsky23)
• Total water vapor along LOS path(vap)

TWP/SMET/C1 - Reprocess: Barometric pressure units change

Barometric pressure data during this time period is reported in hPa.  After this time, the 
data have been converted to kPa to standardize the measurement units among ARM sites and 
to conform to accepted standard units determined by the scientific community.

• Atmospheric pressure(atmos_pressure)

TWP/SMET/C1 - Reprocess: Tipping bucket rain gauge added

A tipping bucket rain gauge was added to the TWP.C1 SMET suite of instruments on 20061017. 
 Effective 20060926, two new variables (count and rain amount) were added to the end of 
the twpsmet60sC1.b1 datastream.  Between 9/26 and 10/17, the data for these two variables 
are filled with zeros.  Users should not use the data during this period as the zeros 
are not representative of the rain fall at the site.  When reprocessing of this datastream 
occurs these variables will be added for the 19961009-20060926 and data from 
19961009-20061017 will be filled with -9999 (missing).

• base_time

TWP/MWR/C1 - Missing data

Data are missing and unrecoverable.

• actel
• tkair
• Temperature, Sky Infra-Red(sky_ir_temp)
• lon
• actaz
• bb31
• tnd_nom23
• sky23
• bbn23
• tkxc
• tnd31
• Temperature, brightness, longwave(ir_temp)
• sky31
• tc23
• tkbb
• time_offset
• 23.8 GHz sky brightness temperature(tbsky23)
• wet_window
• bbn31
• bb23
• tnd_nom31
• Total liquid water along LOS path(liq)
• 31.4 GHz sky brightness temperature(tbsky31)
• tc31
• tnd23
• lat
• tknd
• base_time
• alt
• Total water vapor along LOS path(vap)

TWP/SMET/C1 - Missing data

Data are missing and unrecoverable.

• up_dir_sd
• lo_spd_vec_avg
• up_spd_max
• lo_dir_vec_avg
• logger_temp
• up_dir_vec_avg
• Precipitation maximum(precip_max)
• time_offset
• up_spd_min
• Temperature mean(temp_mean)
• Precipitation minimum(precip_min)
• time
• relh_sd
• internal_voltage
• lat
• alt
• lo_spd_sd
• base_time
• lo_spd_max
• lo_spd_min
• Relative humidity mean(relh_mean)
• vappress_sd
• up_spd_sd
• tbrg_count_total
• Atmospheric pressure(atmos_pressure)
• up_spd_arith_avg
• precip_sd
• tbrg_total
• temp_sd
• Precipitation mean(precip_mean)
• lo_spd_arith_avg
• lon
• lo_dir_sd
• Vapor pressure mean(vappress_mean)
• up_spd_vec_avg

TWP/SMET/C1 - Wind Speed data contain offset due to induced voltage

The marine model of the RM Young wind sensor needs twisted pair shielded cable.  The 
manufacturer did not originally supply the pigtail with twisted pair shielded cable.  Use of 
twisted pair shielded cable for the rest of the cable run to the logger was also not 
specified.  This caused an induced voltage in the wind speed line from the wind direction 
excitation.  The induced voltage varied from sensor to sensor and probably changed anytime 
the cable was replaced or parts of the wind sensor were repaired or replaced. The induced 
voltage has been seen to vary from 0.15 m/s to as much as 1.08 m/s.

• lo_spd_max
• lo_spd_vec_avg
• up_spd_max
• lo_spd_arith_avg
• lo_spd_min
• up_spd_sd
• up_spd_arith_avg
• up_spd_vec_avg
• up_spd_min
• lo_spd_sd

Calibration interruption at TWP Nauru

Occasional calibration interuption occured while calibration SMET instruments

• logger_temp
• Wind #1 speed arithmetic average(wind1_spd_arith_avg)
• Wind #2 speed maximum gust(wind2_spd_max_gust)
• time_offset
• Relative humidity maximum(relh_max)
• Wind #2 speed arithmetic average(wind2_spd_arith_avg)
• Temperature mean(temp_mean)
• Wind #1 speed minimum(wind1_spd_min)
• Wind #1 direction vector average(wind1_dir_vec_avg)
• Wind #2 speed maximum(wind2_spd_max)
• external_voltage
• lat
• wind1_dir_sd
• Atmospheric pressure(atmos_pressure)
• Wind #1 speed vector average(wind1_spd_vec_avg)
• Temperature maximum(temp_max)
• wind2_spd_sd
• wind2_dir_sd
• bit_data
• Wind #1 speed maximum(wind1_spd_max)
• lon
• filename
• Relative humidity minimum(relh_min)
• Wind #1 speed maximum gust(wind1_spd_max_gust)
• Precipitation maximum(precip_max)
• Wind #2 direction vector average(wind2_dir_vec_avg)
• Precipitation minimum(precip_min)
• relh_sd
• internal_voltage
• Wind #2 speed minimum(wind2_spd_min)
• alt
• base_time
• Temperature minimum(temp_min)
• Relative humidity mean(relh_mean)
• vappress_sd
• wind1_spd_sd
• precip_sd
• Wind #2 speed vector average(wind2_spd_vec_avg)
• temp_sd
• Precipitation mean(precip_mean)
• Vapor pressure mean(vappress_mean)

• Raw data stream - documentation not supported

• Atmospheric pressure(atmos_pressure)
• Temperature mean(temp_mean)
• Temperature minimum(temp_min)
• Wind #2 speed minimum(wind2_spd_min)
• lon
• Precipitation maximum(precip_max)
• lat
• Wind #1 speed maximum(wind1_spd_max)
• Wind #2 speed maximum gust(wind2_spd_max_gust)
• Precipitation mean(precip_mean)
• precip_sd
• Wind #1 speed maximum gust(wind1_spd_max_gust)
• vappress_sd
• relh_sd
• time_offset
• Vapor pressure mean(vappress_mean)
• Precipitation minimum(precip_min)
• logger_temp
• bit_data
• Wind #2 speed arithmetic average(wind2_spd_arith_avg)
• temp_sd
• internal_voltage
• Wind #2 speed maximum(wind2_spd_max)
• Wind #1 speed arithmetic average(wind1_spd_arith_avg)
• Relative humidity mean(relh_mean)
• Relative humidity maximum(relh_max)
• wind2_spd_sd
• alt
• Wind #2 direction vector average(wind2_dir_vec_avg)
• Wind #1 speed vector average(wind1_spd_vec_avg)
• filename
• base_time
• Wind #2 speed vector average(wind2_spd_vec_avg)
• external_voltage
• Relative humidity minimum(relh_min)
• Wind #1 speed minimum(wind1_spd_min)
• wind1_spd_sd
• wind2_dir_sd
• Temperature maximum(temp_max)
• wind1_dir_sd
• Wind #1 direction vector average(wind1_dir_vec_avg)