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 infrared 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.

• Mean 31.4 GHz sky brightness temperature(tbsky31)
• 23.8 GHz sky brightness temperature(tbsky23)
• Total water vapor along LOS path(vap)
• Water, liquid, total along line-of-sight 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.

• bbn23
• bb23
• tkxc
• wet_window
• tnd_nom23
• tnd_nom31
• sky23
• Mean 31.4 GHz sky brightness temperature(tbsky31)
• tnd23
• 23.8 GHz sky brightness temperature(tbsky23)
• tc31
• base_time
• Sky infrared temperature(sky_ir_temp)
• Water, liquid, total along line-of-sight path(liq)
• tkbb
• tnd31
• sky31
• tc23
• tknd
• time_offset
• bb31
• bbn31
• Total water vapor along LOS path(vap)
• tkair

NSA/MWR/C1 - Temperature Stabilization of Noise Diode Impaired

On 1/17 we had a big spike in the data and lost temperature stabilization. The instrument 
had problems maintaining the Noise Diode (ND) temperature since. At ambient temperatures 
under about -20 C the ND was not maintaining the set temperature of 30 C. This problem 
was reported in P010122.1.

Fred Solheim recommended on 1/22 that we powercycle the instrument as it looked like the 
instrument CPU had lost the temperature reference.

So we powercycled the instrument on 1/22 @ 20:30 and lost all comumnication to it; after a 
second powercycling the instrument came back on line and the temperature stabilized 
quickly (within a couple of minutes) to the set temperature (30 C)

Fred Solheim reported after the system was restored:
"I've never seen this behavior before. I don't think it was due to the RF deck physically 
hanging temperature, because the recorded temp dropped about 30 C in one observation 
cycle. If this happens again, send the MWR down along with data files for us to look at."

Data collected in the periode 1/17/2001 6:00 to 1/22/2001 21:45 are questionable since it 
is uncertain whether the temperature really was unstable and what really caused the 
problem.

• Mean 31.4 GHz sky brightness temperature(tbsky31)
• Water, liquid, total along line-of-sight path(liq)
• Total water vapor along LOS path(vap)
• 23.8 GHz sky brightness temperature(tbsky23)
• Temperature, brightness, longwave(ir_temp)
• wet_window

NSA/MWR/C1 - negative sky brightness temperatures

The data exhibit occasional negative sky brightness temperatures.
The problem was corrected when the site operator cleaned the cable connectors and coated 
the terminals with dielectric grease.

• Mean 31.4 GHz sky brightness temperature(tbsky31)
• Water, liquid, total along line-of-sight path(liq)
• Total water vapor along LOS path(vap)
• 23.8 GHz sky brightness temperature(tbsky23)

NSA/MWR/C1 - negative sky brightness temperatures

The data exhibit occasional negative sky brightness temperatures.
The problem was corrected when the computer was reconfigured following a virus infection.

• Mean 31.4 GHz sky brightness temperature(tbsky31)
• Water, liquid, total along line-of-sight path(liq)
• Total water vapor along LOS path(vap)
• 23.8 GHz sky brightness temperature(tbsky23)

NSA/MWR/C1 - Reprocess: calibration change

The thicker (1/2-inch) insulation was installed on the RF deck and the reference 
temperature was reduced from 50 C to 30 C to prevent thermal instability in winter. A change in 
the mixer temperature affects the instrument's calibration. A new calibration was 
automatically derived and applied after 1500 valid tip curves were acquired. During the period 
after the temperature was reset and before the calibration was updated, the previous 
calibration was used.

• Mean 31.4 GHz sky brightness temperature(tbsky31)
• Water, liquid, total along line-of-sight path(liq)
• Total water vapor along LOS path(vap)
• 23.8 GHz sky brightness temperature(tbsky23)

NSA/MWR/C1 - incorrect flagging of data

The wet window flag is set high more than expected.

• wet_window

NSA/MWR/C1 - incorrect flagging of data

The wet window flag is set high more frequent than expected.

• wet_window

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 infrared temperature(sky_ir_temp)

NSA/MWR/C1 - Reprocess: calibration change

The computer was replaced but not configured correctly for the MWR.

• Mean 31.4 GHz sky brightness temperature(tbsky31)
• Water, liquid, total along line-of-sight path(liq)
• Total water vapor along LOS path(vap)
• 23.8 GHz sky brightness temperature(tbsky23)

NSA/MWR/C1 - Reprocess: wrong calibration

Moisture was found inside the lens of the MWR. Removal of the moisture caused a 
significant change in the calibration, especially in the 23.8 GHz channel. The calibration was 
updated automatically.

• Mean 31.4 GHz sky brightness temperature(tbsky31)
• Water, liquid, total along line-of-sight path(liq)
• Total water vapor along LOS path(vap)
• 23.8 GHz sky brightness temperature(tbsky23)

NSA/MWR/C1 - Contamination or Calibration Effect

A short period of odd data occurs in PWV and the LWP.  Its a sudden offset in the data 
values.  Vic Morris suggests it could be a calibration issue as seen before at SGP.  Data 
make a marked change after the events (suggesting the data were questionable prior to this 
time).  No obvious changes in other instruments occur. Some of these effects may coincide 
with operator's preventive maintenance but others are in the middle of the night local 
time and can not be explained by cleaning.

• Water, liquid, total along line-of-sight path(liq)
• Total water vapor along LOS path(vap)

NSA/MWR/C1 - Frosting

Spike in PWV and LWP
. Operator reports instrument is frosted. Instrument teflon window was cleaned by 
operator.

• Water, liquid, total along line-of-sight path(liq)
• Total water vapor along LOS path(vap)

NSA/MWR/C1 - Instrument maintenance

Installed cold weather insulation on radiometer, required time to thermally stabilize.

• Mean 31.4 GHz sky brightness temperature(tbsky31)
• Water, liquid, total along line-of-sight path(liq)
• 23.8 GHz sky brightness temperature(tbsky23)
• tnd23
• tknd
• tnd31
• bb23
• tnd_nom23
• tc23
• sky31
• tnd_nom31
• bb31
• tc31
• Sky infrared temperature(sky_ir_temp)
• sky23
• tkxc
• Total water vapor along LOS path(vap)
• Temperature, brightness, longwave(ir_temp)
• tkbb
• bbn23
• wet_window
• bbn31
• tkair

NSA/MWR/C1 - MWR moved

The MWR data are unreasonable during this period, because it was shutdown and moved by 
operations at this time.

• Mean 31.4 GHz sky brightness temperature(tbsky31)
• East longitude(lon)
• tnd23
• tknd
• tnd_nom23
• bb31
• sky23
• Sky infrared temperature(sky_ir_temp)
• tkxc
• Total water vapor along LOS path(vap)
• Altitude above mean sea level(alt)
• tkbb
• time_offset
• wet_window
• bbn23
• base_time
• tkair
• North latitude(lat)
• Water, liquid, total along line-of-sight path(liq)
• 23.8 GHz sky brightness temperature(tbsky23)
• tnd31
• bb23
• tc23
• sky31
• tnd_nom31
• actel
• tc31
• Temperature, brightness, longwave(ir_temp)
• actaz
• bbn31

NSA/MWR/C1 - negative PWV (bad calibration?)

During this time, the PWV drops to slightly negative values.  This could be related to 
calibration issues.

• Total water vapor along LOS path(vap)

NSA/MWR/C1 - Heater/blower removed

Note that the heater/blower was removed from the MWR during this time.  This may impact 
snow removal from teflon window, thereby affecting the quality of the data between 
cleanings.

• Mean 31.4 GHz sky brightness temperature(tbsky31)
• Water, liquid, total along line-of-sight path(liq)
• 23.8 GHz sky brightness temperature(tbsky23)
• tnd23
• tknd
• tnd31
• tnd_nom23
• tc23
• sky31
• tnd_nom31
• tc31
• Sky infrared temperature(sky_ir_temp)
• sky23
• tkxc
• Total water vapor along LOS path(vap)
• Temperature, brightness, longwave(ir_temp)
• tkbb
• wet_window
• tkair

NSA/MWR/C1 - Data spikes, possibly due to cleaning events

Unreasonable spikes occurred, which may be due to cleaning of 
the instrument by the operator.  Other cleaning events did
not result in obvious data spikes and have not been included 
in this report.

• Mean 31.4 GHz sky brightness temperature(tbsky31)
• Water, liquid, total along line-of-sight path(liq)
• Total water vapor along LOS path(vap)
• 23.8 GHz sky brightness temperature(tbsky23)

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 infrared temperature(sky_ir_temp)

NSA/MWR/C1 - MWR digital board failure

A power failure at the site apparently damaged some of the components of the digital 
board. The MWR was replaced with a spare unit and returned to the manufacturer for repair.

• Mean 31.4 GHz sky brightness temperature(tbsky31)
• Water, liquid, total along line-of-sight path(liq)
• Total water vapor along LOS path(vap)
• 23.8 GHz sky brightness temperature(tbsky23)

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.

• bbn23
• bb23
• tkxc
• wet_window
• tnd_nom23
• sky23
• tnd_nom31
• Mean 31.4 GHz sky brightness temperature(tbsky31)
• tnd23
• tc31
• 23.8 GHz sky brightness temperature(tbsky23)
• Sky infrared temperature(sky_ir_temp)
• Water, liquid, total along line-of-sight path(liq)
• tkbb
• tnd31
• sky31
• tc23
• tknd
• time_offset
• bb31
• bbn31
• Total water vapor along LOS path(vap)
• tkair

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.

• Mean 31.4 GHz sky brightness temperature(tbsky31)
• 23.8 GHz sky brightness temperature(tbsky23)
• Total water vapor along LOS path(vap)
• Water, liquid, total along line-of-sight path(liq)

SGP/MWR/C1 - Intermittent Negative Sky Brightness Temperatures

Several related and recurring problems with the 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, spikes in the data, 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.

Because these all initially appeared to be hardware-related problems,
the instrument mentor and 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 did 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.

• Mean 31.4 GHz sky brightness temperature(tbsky31)
• Water, liquid, total along line-of-sight path(liq)
• Total water vapor along LOS path(vap)
• 23.8 GHz sky brightness temperature(tbsky23)

NSA/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 and modifying the MWR software to read 
the signal from the appropriate corresponding channel.

• tkair

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
• tkxc

NSA/MWR/C1 - min/max/delta values incorrect

The values of valid_min, valid_max, and valid_delta for fields tkxc and tknd were 
incorrect. They should be 303, 333, and 0.5 K, respectively.

• tkxc
• tknd

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.

• tkair

NSA/MWR/C1 - damaged window

The MWR dielectric window was damaged by snow from a snow blower and replaced.

• Mean 31.4 GHz sky brightness temperature(tbsky31)
• Water, liquid, total along line-of-sight path(liq)
• 23.8 GHz sky brightness temperature(tbsky23)
• tnd23
• tknd
• tnd31
• tnd_nom23
• bb23
• tc23
• sky31
• tnd_nom31
• bb31
• tc31
• sky23
• tkxc
• Total water vapor along LOS path(vap)
• tkbb
• bbn23
• wet_window
• bbn31
• tkair

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.

• wet_window
• Mean 31.4 GHz sky brightness temperature(tbsky31)
• 23.8 GHz sky brightness temperature(tbsky23)
• Total water vapor along LOS path(vap)
• Water, liquid, total along line-of-sight path(liq)

SGP/MWR/C1 - Instrument problem

The MWR mixer temperature, blackbody temperature, and moisture flag are incorrect. This 
began when the instrument was returned to service after the analog board was temporarily 
removed to check the presence and absence of certain resistors. The board must have been 
accidently damaged during this process.

• tkbb
• tnd31
• tc23
• tknd
• tkxc
• wet_window
• tnd_nom23
• tnd_nom31
• tnd23
• tc31
• tkair

SGP/MWR/C1 - thermal instability

The analog board was replaced with a spare (D041001.3) with a reference temperature that 
was set too low (306 K) so that during periods of high ambient temperature, the instrument 
became thermally unstable. The problem was corrected when the temperature setting was 
increased (to 311 K).

• Mean 31.4 GHz sky brightness temperature(tbsky31)
• 23.8 GHz sky brightness temperature(tbsky23)
• Total water vapor along LOS path(vap)
• Water, liquid, total along line-of-sight path(liq)

NSA/MWRP/C1 - Missing data

Data are missing and unrecoverable.

• Pressure, level of free convection(levelFreeConvectionPres)
• Temperature, virtual, vert. prof. sfc-10km, fr. wtr. vap. dens. and temp. prof.(virtualTemperature)
• Pressure, lifting condensation level(liftingCondensationLevelPres)
• dataQualityFlags
• Pressure, equilibrium level(equilibriumLevelPres)
• Density, water vapor, at instrument height (1 or 2 m)(surfaceWaterVaporDensity)
• totalPrecipitableWater2RmsError
• Humidity, relative, prof. from sfc.-10km, from water vap. dens. and temp. prof.(relativeHumidity)
• Liquid water content, cloud, vert. prof. sfc.-10km, from Tbright stat. retrvl.(liquidWaterContent)
• wetWindowFlag
• Liquid water path, from Tbright at 23.835 and 30.0 GHz only, using stat. retrvl.(liquidWaterPath2)
• Height, equilibrium level(equilibriumLevel)
• infraredTemperature
• CAPE, Convective available potential energy(cape)
• time
• time_offset
• liquidWaterPathRmsError
• waterVaporDensityRmsError
• surface pressure(pressure)
• blackbodyTemperature
• Microwave brightness temperature(brightnessTemperature)
• Liquid water path, from brightness temperatures using statistical retrieval(liquidWaterPath)
• Mixing ratio, water vap., vert. prof. sfc-10km, frm retr. water vap. dens. prof(waterVaporMixingRatio)
• Altitude above mean sea level(alt)
• Pressure, barometric. at instrument height (1 or 2 m)(surfacePressure)
• Height, lifting condensation level(liftingCondensationLevel)
• Pressure, associated geometric height, at altitude, NGM model output(height)
• Height, level of free convection(levelFreeConvection)
• elevation
• liquidWaterContentRmsError
• Humidity, relative, at instrument height (1 or 2 m)(surfaceRelativeHumidity)
• liquidWaterPath2RmsError
• Temperature, dew point, vert. prof. sfc-10km, from water vapor density prof.(dewpointTemperature)
• Temperature, air, at instrument height (1 or 2 m)(surfaceTemperature)
• frequency
• temperatureRmsError
• Water vapor, total precipitable, derived from Tbright using stat. retrvl.(totalPrecipitableWater)
• MET air temperature(temperature)
• base_time
• Density, water vapor, prof. from sfc.-10 km, der. from Tbright stat. retrvl.(waterVaporDensity)
• totalPrecipitableWaterRmsError
• East longitude(lon)
• Height, cloud base, height where IR temp. matches retrieved temp. profile(cloudBaseHeight)
• North latitude(lat)
• azimuth
• Water vapor, tot. precipitable, from Tbright, 23.835 & 30.0 GHz, stat. retrvl.(totalPrecipitableWater2)

SGP/MWR/C1 - Reprocess: wrong retrievals

When the computer and core configuration were upgraded, retrieval coefficients for BF1 
were accidently included in the configuration file.
The correct coefficients for CF1 were applied when the configuration file was updated.

• Total water vapor along LOS path(vap)
• Water, liquid, total along line-of-sight path(liq)

NSA/C1 - Site-wide power failure

The Barrow facility experienced a site-wide power failure on 12/13.  Power was restored to 
most instruments between 2250 and 2330 GMT.

• Mean 31.4 GHz sky brightness temperature(tbsky31)
• Sky infrared temperature(sky_ir_temp)
• sky23
• tkxc
• Total water vapor along LOS path(vap)
• Altitude above mean sea level(alt)
• tkbb
• bbn23
• base_time
• tkair
• bb23
• sky31
• tnd_nom31
• Temperature, brightness, longwave(ir_temp)
• bbn31
• East longitude(lon)
• tnd23
• tknd
• tnd_nom23
• bb31
• time_offset
• wet_window
• North latitude(lat)
• Water, liquid, total along line-of-sight path(liq)
• 23.8 GHz sky brightness temperature(tbsky23)
• tnd31
• tc23
• actel
• tc31
• actaz

• Pressure, level of free convection(levelFreeConvectionPres)
• Pressure, lifting condensation level(liftingCondensationLevelPres)
• wetWindowFlag
• Liquid water path, from Tbright at 23.835 and 30.0 GHz only, using stat. retrvl.(liquidWaterPath2)
• infraredTemperature
• time
• liquidWaterPathRmsError
• Liquid water path, from brightness temperatures using statistical retrieval(liquidWaterPath)
• Microwave brightness temperature(brightnessTemperature)
• Mixing ratio, water vap., vert. prof. sfc-10km, frm retr. water vap. dens. prof(waterVaporMixingRatio)
• Altitude above mean sea level(alt)
• Pressure, associated geometric height, at altitude, NGM model output(height)
• Height, lifting condensation level(liftingCondensationLevel)
• liquidWaterContentRmsError
• Temperature, air, at instrument height (1 or 2 m)(surfaceTemperature)
• Temperature, dew point, vert. prof. sfc-10km, from water vapor density prof.(dewpointTemperature)
• temperatureRmsError
• Water vapor, total precipitable, derived from Tbright using stat. retrvl.(totalPrecipitableWater)
• MET air temperature(temperature)
• base_time
• totalPrecipitableWaterRmsError
• East longitude(lon)
• Height, cloud base, height where IR temp. matches retrieved temp. profile(cloudBaseHeight)
• North latitude(lat)
• azimuth
• Temperature, virtual, vert. prof. sfc-10km, fr. wtr. vap. dens. and temp. prof.(virtualTemperature)
• dataQualityFlags
• Pressure, equilibrium level(equilibriumLevelPres)
• Density, water vapor, at instrument height (1 or 2 m)(surfaceWaterVaporDensity)
• totalPrecipitableWater2RmsError
• Humidity, relative, prof. from sfc.-10km, from water vap. dens. and temp. prof.(relativeHumidity)
• Liquid water content, cloud, vert. prof. sfc.-10km, from Tbright stat. retrvl.(liquidWaterContent)
• Height, equilibrium level(equilibriumLevel)
• CAPE, Convective available potential energy(cape)
• time_offset
• waterVaporDensityRmsError
• surface pressure(pressure)
• blackbodyTemperature
• Pressure, barometric. at instrument height (1 or 2 m)(surfacePressure)
• elevation
• Height, level of free convection(levelFreeConvection)
• Humidity, relative, at instrument height (1 or 2 m)(surfaceRelativeHumidity)
• liquidWaterPath2RmsError
• frequency
• Density, water vapor, prof. from sfc.-10 km, der. from Tbright stat. retrvl.(waterVaporDensity)
• Water vapor, tot. precipitable, from Tbright, 23.835 & 30.0 GHz, stat. retrvl.(totalPrecipitableWater2)

NSA/MWR/C1 - poor air temperature values

After the air temperature sensor was rewired due to a change with the new blower 
(D030515.3), the measurement was initially incorrect. There is no apparent cause for the bad 
signal or its improvement.

• tkair

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.

• bbn23
• tkxc
• wet_window
• East longitude(lon)
• tnd_nom31
• tc31
• 23.8 GHz sky brightness temperature(tbsky23)
• Water, liquid, total along line-of-sight path(liq)
• tkbb
• North latitude(lat)
• sky31
• tc23
• time_offset
• bb31
• Total water vapor along LOS path(vap)
• bbn31
• tkair
• bb23
• tnd_nom23
• sky23
• Mean 31.4 GHz sky brightness temperature(tbsky31)
• tnd23
• base_time
• Sky infrared temperature(sky_ir_temp)
• tnd31
• tknd
• Altitude above mean sea level(alt)

SGP/MWR/C1 - REPROCESS - Revised Retrieval Coefficients

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

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

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

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

PWV_MONORTM = 0.9695 * PWV_ROSENKRANZ
LWP_MONORTM = 1.026  * LWP_ROSENKRANZ

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

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

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

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

• Total water vapor along LOS path(vap)
• Water, liquid, total along line-of-sight path(liq)

NSA/MWR/C1 - Reprocess: Revised Calibration Coefficients

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

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

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

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

PWV_MONORTM = 0.9695 * PWV_ROSENKRANZ
LWP_MONORTM = 1.026  * LWP_ROSENKRANZ

The Rosenkranz-based retrieval coefficients became active at NSA.C1 
20020425.1900.  The MONORTM-based retrieval coefficients became active 
at NSA.C1 20050629.0000.

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

• Water, liquid, total along line-of-sight path(liq)
• Total water vapor along LOS path(vap)

NSA/MWR/C1 - Possible loss of accuracy due to missing blower

On 7/09 the MWR blower failed. The blower prevents snow and liquid drop from accumulating 
on the window. Accumulation of snow or liquid results in a loss of accuracy of the 
instrument. The loss of accuracy has consequencies on the retrieved liquid water path and 
precipitable water vapor. Usually there will be an overestimation of liquid and vapor. The 
blower was repaired and reinstalled on 7/20. Between 7/9 and 7/20 the tkair variable is 
unavailable as well.

• Mean 31.4 GHz sky brightness temperature(tbsky31)
• sky23
• Water, liquid, total along line-of-sight path(liq)
• Total water vapor along LOS path(vap)
• 23.8 GHz sky brightness temperature(tbsky23)
• wet_window
• tkair
• sky31

NSA/MWRP/C1 - Blower assembly failure

The MWRP had a problem with the ambient temperature sensor situated in the blower 
assembly. This caused corrupted data files and software crashes. The blower assembly was removed 
and sent to the vendor for repair on 9/21, and re-installed on 10/12.

• Pressure, level of free convection(levelFreeConvectionPres)
• Temperature, virtual, vert. prof. sfc-10km, fr. wtr. vap. dens. and temp. prof.(virtualTemperature)
• Pressure, lifting condensation level(liftingCondensationLevelPres)
• Pressure, equilibrium level(equilibriumLevelPres)
• dataQualityFlags
• Density, water vapor, at instrument height (1 or 2 m)(surfaceWaterVaporDensity)
• totalPrecipitableWater2RmsError
• Humidity, relative, prof. from sfc.-10km, from water vap. dens. and temp. prof.(relativeHumidity)
• Liquid water content, cloud, vert. prof. sfc.-10km, from Tbright stat. retrvl.(liquidWaterContent)
• wetWindowFlag
• Liquid water path, from Tbright at 23.835 and 30.0 GHz only, using stat. retrvl.(liquidWaterPath2)
• Height, equilibrium level(equilibriumLevel)
• infraredTemperature
• CAPE, Convective available potential energy(cape)
• liquidWaterPathRmsError
• waterVaporDensityRmsError
• surface pressure(pressure)
• blackbodyTemperature
• Microwave brightness temperature(brightnessTemperature)
• Liquid water path, from brightness temperatures using statistical retrieval(liquidWaterPath)
• Mixing ratio, water vap., vert. prof. sfc-10km, frm retr. water vap. dens. prof(waterVaporMixingRatio)
• Pressure, barometric. at instrument height (1 or 2 m)(surfacePressure)
• Height, lifting condensation level(liftingCondensationLevel)
• Pressure, associated geometric height, at altitude, NGM model output(height)
• Height, level of free convection(levelFreeConvection)
• elevation
• liquidWaterContentRmsError
• Humidity, relative, at instrument height (1 or 2 m)(surfaceRelativeHumidity)
• liquidWaterPath2RmsError
• Temperature, dew point, vert. prof. sfc-10km, from water vapor density prof.(dewpointTemperature)
• Temperature, air, at instrument height (1 or 2 m)(surfaceTemperature)
• frequency
• temperatureRmsError
• Water vapor, total precipitable, derived from Tbright using stat. retrvl.(totalPrecipitableWater)
• MET air temperature(temperature)
• Density, water vapor, prof. from sfc.-10 km, der. from Tbright stat. retrvl.(waterVaporDensity)
• totalPrecipitableWaterRmsError
• Height, cloud base, height where IR temp. matches retrieved temp. profile(cloudBaseHeight)
• azimuth
• Water vapor, tot. precipitable, from Tbright, 23.835 & 30.0 GHz, stat. retrvl.(totalPrecipitableWater2)

SGP/MWR/C1 - Instrument noise problem

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

• bbn23
• bb23
• tkxc
• wet_window
• tnd_nom23
• tnd_nom31
• sky23
• Mean 31.4 GHz sky brightness temperature(tbsky31)
• tnd23
• tc31
• 23.8 GHz sky brightness temperature(tbsky23)
• Sky infrared temperature(sky_ir_temp)
• Water, liquid, total along line-of-sight path(liq)
• tkbb
• tnd31
• sky31
• tc23
• tknd
• bb31
• Total water vapor along LOS path(vap)
• bbn31
• tkair

NSA/MWR/C1 - Instrument problem, Heater problem

The heater of the MWR was ON all the time even when the moisture sensor was dry. Jim 
Liljegren suspected a problem with the relay that activates the heater. The suggested action 
was to send the faulty assembly to SGP for repair and get a spare unit from SGP.
The spare unit was sent on 9/15 and was installed on 10/18.

• Mean 31.4 GHz sky brightness temperature(tbsky31)
• East longitude(lon)
• tnd23
• tknd
• tnd_nom23
• bb31
• sky23
• Sky infrared temperature(sky_ir_temp)
• tkxc
• Total water vapor along LOS path(vap)
• Altitude above mean sea level(alt)
• tkbb
• time_offset
• wet_window
• bbn23
• base_time
• tkair
• North latitude(lat)
• Water, liquid, total along line-of-sight path(liq)
• 23.8 GHz sky brightness temperature(tbsky23)
• tnd31
• bb23
• tc23
• sky31
• tnd_nom31
• actel
• tc31
• Temperature, brightness, longwave(ir_temp)
• actaz
• bbn31

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

A problem began with the installation of MWR.EXE version 4.12 in September 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 9/15/2005. As a consequence of this 
upgrade, the tip curve frequency increased. The tip cycle time decreased from ~60s to ~50s.

• Mean 31.4 GHz sky brightness temperature(tbsky31)
• Water, liquid, total along line-of-sight path(liq)
• 23.8 GHz sky brightness temperature(tbsky23)
• tnd23
• tknd
• tnd31
• tnd_nom23
• bb23
• tc23
• sky31
• tnd_nom31
• bb31
• tc31
• Sky infrared temperature(sky_ir_temp)
• sky23
• tkxc
• Total water vapor along LOS path(vap)
• Temperature, brightness, longwave(ir_temp)
• tkbb
• bbn23
• bbn31
• tkair

NSA/MWR/C1 - Reprocessed and Corrected:wrong calibration

DATA REPROCESSED and CORRECTED: 

The calibration had changed as a result of the repairs made by Radiometrics and the RF 
deck temperature had been set to 325K for testing. The temperature was decreased to 307K to 
prevent thermal instability in winter and the calibration was changed in the 
configuration file with the values supplied on the repair report. The calibration coefficients were 
derived automatically after the changes were put into affect. The data were reprocessed 
using the derived calibration coefficients.

ORIGINAL DQR CATEGORY: Red( Incorrect)

REPROCESSED and CORRECTED DATA ARCHIVED:2016-03-29

REPROCESS IDENTIFICATION NUMBER: RID 209
 
---------------------------------------------------
--- ORIGINAL DQR DESCRIPTION ---
---------------------------------------------------
When MWR#20 was returned to service on 9/1/2005, the calibration had changed as a result 
of the repairs made by Radiometrics and the RF deck temperature had been set to 325K for 
testing. On 9/2, the temperature was decreased to 307K to prevent thermal instability in 
winter and the calibration was changed in the configuration file with the values supplied 
on the repair report.  

The data need to be reprocessed with the calibration coefficients that were automatically 
derived after these changes were put into affect. They are: tnd_nom23=185.621, 
tnd_nom31=158.801, tc23=-0.022, tc31=-0.039.

• Mean 31.4 GHz sky brightness temperature(tbsky31)
• Water, liquid, total along line-of-sight path(liq)
• Total water vapor along LOS path(vap)
• 23.8 GHz sky brightness temperature(tbsky23)

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.

• bbn23
• bb23
• tkxc
• tnd_nom23
• tnd_nom31
• sky23
• Mean 31.4 GHz sky brightness temperature(tbsky31)
• tnd23
• tc31
• 23.8 GHz sky brightness temperature(tbsky23)
• Sky infrared temperature(sky_ir_temp)
• Water, liquid, total along line-of-sight path(liq)
• tkbb
• tnd31
• sky31
• tc23
• tknd
• bb31
• bbn31
• Total water vapor along LOS path(vap)
• tkair

NSA/MWR/C1 -  Incorrect time stamp

On Sept 27 the motherboard of the MWR computer was replaced. Following the replacement, 
the date on the computer was not set to the correct time of day, therefore the date and 
time in the files were wrong. The time on the computer was reset on Sept. 30. Time stamps 
between Sept. 27 and Sept. 30 were later corrected based on gathered information, however 
they may have as much as 5 minutes of uncertainty.

• Mean 31.4 GHz sky brightness temperature(tbsky31)
• East longitude(lon)
• tnd23
• tknd
• tnd_nom23
• bb31
• sky23
• Sky infrared temperature(sky_ir_temp)
• tkxc
• Total water vapor along LOS path(vap)
• Altitude above mean sea level(alt)
• tkbb
• time_offset
• wet_window
• bbn23
• base_time
• tkair
• North latitude(lat)
• Water, liquid, total along line-of-sight path(liq)
• 23.8 GHz sky brightness temperature(tbsky23)
• tnd31
• bb23
• tc23
• sky31
• tnd_nom31
• actel
• tc31
• Temperature, brightness, longwave(ir_temp)
• actaz
• bbn31

NSA/MWRP/C1 - Incorrect calibration

On 4/12 a calibration was attempted but the calibration was not successful. A new 
calibration was completed on 4/13 20:00 UTC.  Data between the two calibration attempts are 
incorrect and should be disregarded.

• Pressure, level of free convection(levelFreeConvectionPres)
• Temperature, virtual, vert. prof. sfc-10km, fr. wtr. vap. dens. and temp. prof.(virtualTemperature)
• Pressure, lifting condensation level(liftingCondensationLevelPres)
• dataQualityFlags
• Pressure, equilibrium level(equilibriumLevelPres)
• Density, water vapor, at instrument height (1 or 2 m)(surfaceWaterVaporDensity)
• totalPrecipitableWater2RmsError
• Humidity, relative, prof. from sfc.-10km, from water vap. dens. and temp. prof.(relativeHumidity)
• Liquid water content, cloud, vert. prof. sfc.-10km, from Tbright stat. retrvl.(liquidWaterContent)
• wetWindowFlag
• Liquid water path, from Tbright at 23.835 and 30.0 GHz only, using stat. retrvl.(liquidWaterPath2)
• Height, equilibrium level(equilibriumLevel)
• infraredTemperature
• CAPE, Convective available potential energy(cape)
• time
• time_offset
• liquidWaterPathRmsError
• waterVaporDensityRmsError
• surface pressure(pressure)
• blackbodyTemperature
• Microwave brightness temperature(brightnessTemperature)
• Liquid water path, from brightness temperatures using statistical retrieval(liquidWaterPath)
• Mixing ratio, water vap., vert. prof. sfc-10km, frm retr. water vap. dens. prof(waterVaporMixingRatio)
• Altitude above mean sea level(alt)
• Pressure, barometric. at instrument height (1 or 2 m)(surfacePressure)
• Height, lifting condensation level(liftingCondensationLevel)
• Pressure, associated geometric height, at altitude, NGM model output(height)
• Height, level of free convection(levelFreeConvection)
• elevation
• liquidWaterContentRmsError
• Humidity, relative, at instrument height (1 or 2 m)(surfaceRelativeHumidity)
• liquidWaterPath2RmsError
• Temperature, dew point, vert. prof. sfc-10km, from water vapor density prof.(dewpointTemperature)
• Temperature, air, at instrument height (1 or 2 m)(surfaceTemperature)
• frequency
• temperatureRmsError
• Water vapor, total precipitable, derived from Tbright using stat. retrvl.(totalPrecipitableWater)
• MET air temperature(temperature)
• base_time
• Density, water vapor, prof. from sfc.-10 km, der. from Tbright stat. retrvl.(waterVaporDensity)
• totalPrecipitableWaterRmsError
• East longitude(lon)
• Height, cloud base, height where IR temp. matches retrieved temp. profile(cloudBaseHeight)
• North latitude(lat)
• azimuth
• Water vapor, tot. precipitable, from Tbright, 23.835 & 30.0 GHz, stat. retrvl.(totalPrecipitableWater2)

NSA/MWR/C1 - software upgrade (version 3.28)

The MWR operating program was upgraded to version 3.28 on 3 February 1999. This version 
includes a beam width correction 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.)

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.

• Mean 31.4 GHz sky brightness temperature(tbsky31)
• Water, liquid, total along line-of-sight path(liq)
• Total water vapor along LOS path(vap)
• 23.8 GHz sky brightness temperature(tbsky23)

NSA/MWRP/C1 - Bad calibration values

After calibration was completed on 4/26/2006 the last value in the V-band calibration file 
was corrupted. V-band data are wrong between 4/26 19:30 and 4/27 15:27 when the 
corrupted values were removed.

• waterVaporDensityRmsError
• Temperature, virtual, vert. prof. sfc-10km, fr. wtr. vap. dens. and temp. prof.(virtualTemperature)
• MET air temperature(temperature)
• Density, water vapor, prof. from sfc.-10 km, der. from Tbright stat. retrvl.(waterVaporDensity)
• Humidity, relative, prof. from sfc.-10km, from water vap. dens. and temp. prof.(relativeHumidity)
• Height, cloud base, height where IR temp. matches retrieved temp. profile(cloudBaseHeight)
• Liquid water content, cloud, vert. prof. sfc.-10km, from Tbright stat. retrvl.(liquidWaterContent)
• Microwave brightness temperature(brightnessTemperature)
• Mixing ratio, water vap., vert. prof. sfc-10km, frm retr. water vap. dens. prof(waterVaporMixingRatio)
• Temperature, dew point, vert. prof. sfc-10km, from water vapor density prof.(dewpointTemperature)

SGP/MWR/C1 - Spikes in ambient temperature readings

There are intermittent spikes in the Tkair temperature (T ~ 400 K). On 7/28 the sensor 
was cleaned and the instrument power cycled following a power outage. Readings came back to 
normal.

• tkair

NSA/MWR/C1 - TKAIR sensor failure

Between 7/14 and 7/28 the tkair variable is missing most of the time and sometimes has 
large negative spikes.  On 7/28, the sensor was cleaned of corrosion and the readings came 
back to normal.

• tkair

NSA/MWRP/C1 - Reprocessed: Re-calibration

After being re-installed the radiometer was calibrated with liquid nitrogen.
Data between 8/8 and 9/6 have been reprocessed to apply the revised calibrations.

• Pressure, level of free convection(levelFreeConvectionPres)
• Temperature, virtual, vert. prof. sfc-10km, fr. wtr. vap. dens. and temp. prof.(virtualTemperature)
• Pressure, lifting condensation level(liftingCondensationLevelPres)
• Pressure, equilibrium level(equilibriumLevelPres)
• totalPrecipitableWater2RmsError
• Density, water vapor, at instrument height (1 or 2 m)(surfaceWaterVaporDensity)
• Liquid water content, cloud, vert. prof. sfc.-10km, from Tbright stat. retrvl.(liquidWaterContent)
• Liquid water path, from Tbright at 23.835 and 30.0 GHz only, using stat. retrvl.(liquidWaterPath2)
• Height, equilibrium level(equilibriumLevel)
• infraredTemperature
• CAPE, Convective available potential energy(cape)
• liquidWaterPathRmsError
• waterVaporDensityRmsError
• blackbodyTemperature
• Microwave brightness temperature(brightnessTemperature)
• Liquid water path, from brightness temperatures using statistical retrieval(liquidWaterPath)
• Mixing ratio, water vap., vert. prof. sfc-10km, frm retr. water vap. dens. prof(waterVaporMixingRatio)
• Height, lifting condensation level(liftingCondensationLevel)
• Height, level of free convection(levelFreeConvection)
• liquidWaterContentRmsError
• Temperature, dew point, vert. prof. sfc-10km, from water vapor density prof.(dewpointTemperature)
• liquidWaterPath2RmsError
• Water vapor, total precipitable, derived from Tbright using stat. retrvl.(totalPrecipitableWater)
• Density, water vapor, prof. from sfc.-10 km, der. from Tbright stat. retrvl.(waterVaporDensity)
• totalPrecipitableWaterRmsError
• Height, cloud base, height where IR temp. matches retrieved temp. profile(cloudBaseHeight)
• Water vapor, tot. precipitable, from Tbright, 23.835 & 30.0 GHz, stat. retrvl.(totalPrecipitableWater2)

NSA/MWR/C1 - Rain sensor always on

The rain sensor was always on between 10/5 and 10/23 2006.
The user should be aware that not all data flagged as rainy are actually rainy. The 
problem was caused by a shift in the sensitivity of the rain sensor and was corrected by 
changing the sensor threshold in the configuration file.

• wet_window

NSA/MWRP/C1 - Reprocessed: K-Band calibration drift

At the beginning of November, the K-band channel calibration started to drift. The MWRP 
brightness temperatures were about 1.5 K higher than the MWR-measured brightness 
temperatures. By the half of the month the differences were more than 2 K to become about 4 K by 
the end of November. On Nov 27 new calibration coefficients were derived and uploaded.

Data for 20061101-20061127 have been reprocessed with the revised calibrations and are 
available from the ARM Archive effective January 2007.

• Pressure, level of free convection(levelFreeConvectionPres)
• Height, lifting condensation level(liftingCondensationLevel)
• Pressure, lifting condensation level(liftingCondensationLevelPres)
• Height, level of free convection(levelFreeConvection)
• Humidity, relative, prof. from sfc.-10km, from water vap. dens. and temp. prof.(relativeHumidity)
• Liquid water content, cloud, vert. prof. sfc.-10km, from Tbright stat. retrvl.(liquidWaterContent)
• Liquid water path, from Tbright at 23.835 and 30.0 GHz only, using stat. retrvl.(liquidWaterPath2)
• CAPE, Convective available potential energy(cape)
• Temperature, dew point, vert. prof. sfc-10km, from water vapor density prof.(dewpointTemperature)
• Water vapor, total precipitable, derived from Tbright using stat. retrvl.(totalPrecipitableWater)
• Density, water vapor, prof. from sfc.-10 km, der. from Tbright stat. retrvl.(waterVaporDensity)
• Microwave brightness temperature(brightnessTemperature)
• Liquid water path, from brightness temperatures using statistical retrieval(liquidWaterPath)
• Mixing ratio, water vap., vert. prof. sfc-10km, frm retr. water vap. dens. prof(waterVaporMixingRatio)
• Water vapor, tot. precipitable, from Tbright, 23.835 & 30.0 GHz, stat. retrvl.(totalPrecipitableWater2)

NSA/MWRP/C1 - Incorrect surface measurements

Surface measurements are spiking and not comparing well with the co-located METTWR 
measurements.

On 2/13 site operators cleaned a filter in the heater housing resolving the problem.

• Density, water vapor, at instrument height (1 or 2 m)(surfaceWaterVaporDensity)
• Pressure, barometric. at instrument height (1 or 2 m)(surfacePressure)
• Humidity, relative, at instrument height (1 or 2 m)(surfaceRelativeHumidity)
• Temperature, air, at instrument height (1 or 2 m)(surfaceTemperature)

SGP/MWR/C1/E14 - Freezing rain-Incorrect rain flag

Between 01/12 and 01/15 brightness temperatures show high values (Tb > 100 K) indicative 
of rain, however the wet_window flag is 0 (indicative of no rain). During that time there 
where freezing conditions with ice pellets that were not detected by the sensor. The high 
brightness temperatures may be due to melting ice on the window.

• wet_window

NSA/MWRP/C1 - Incorrect surface measurements

The MWRP surface temperature and pressure readings were in disagreement with those from 
other instruments. The possible cause of the disagreement was ice buildup around the 
sensors.  Readings returned to normal March 29.

The temperature readings were more affected. Since the readings are erratic, with large 
oscillations, it is not possible to correct them. Disregard the surface temperature and 
humidity readings during this time. The wrong readings will affect the first layer of the 
temperature and humidity profiles as well.

• Density, water vapor, at instrument height (1 or 2 m)(surfaceWaterVaporDensity)
• Pressure, barometric. at instrument height (1 or 2 m)(surfacePressure)
• Humidity, relative, at instrument height (1 or 2 m)(surfaceRelativeHumidity)
• Temperature, air, at instrument height (1 or 2 m)(surfaceTemperature)

NSA/MWRP/C1 - Reprocessed: 6-channel retrieval replaced by 5-channel retrieval

Due to repeated failure of the V-band receiver and calibration problems, the 6-channel 
retrieval was retired and a new 5-channel retrieval which uses only the K-band channels was 
implemented.

All data previously processed with the 6-channel retrieval have been reprocessed.

Please note that the 7 channels (brightness temperatures) in the V-band range (51 to 60 
GHz) should not be used.  See D080331.1 and D080331.2.

• Microwave brightness temperature(brightnessTemperature)
• Liquid water path, from brightness temperatures using statistical retrieval(liquidWaterPath)
• Liquid water path, from Tbright at 23.835 and 30.0 GHz only, using stat. retrvl.(liquidWaterPath2)

SGP/MWR/C1 - Noisy data

Since 7/14 the MWR is experiencing intermittent periods of increased noise. The cause for 
this is under investigation.

• sky31
• bbn23
• bb23
• sky23
• bb31
• Mean 31.4 GHz sky brightness temperature(tbsky31)
• 23.8 GHz sky brightness temperature(tbsky23)
• Total water vapor along LOS path(vap)
• bbn31
• Water, liquid, total along line-of-sight path(liq)

SGP/MWR/C1 - Reprocessed: Radiometer reinstalled

After the radiometer was reinstalled it had to update the calibration coefficients.

Data reprocessed 20071217.

• tnd31
• tc23
• tnd_nom23
• tnd_nom31
• Mean 31.4 GHz sky brightness temperature(tbsky31)
• tnd23
• 23.8 GHz sky brightness temperature(tbsky23)
• tc31
• Total water vapor along LOS path(vap)
• Water, liquid, total along line-of-sight path(liq)

SGP/MWR/C1 - Missing data

Data are missing and unrecoverable.

• bbn23
• tkxc
• wet_window
• East longitude(lon)
• tnd_nom31
• 23.8 GHz sky brightness temperature(tbsky23)
• tc31
• Water, liquid, total along line-of-sight path(liq)
• tkbb
• North latitude(lat)
• sky31
• tc23
• time_offset
• bb31
• Total water vapor along LOS path(vap)
• bbn31
• tkair
• bb23
• tnd_nom23
• sky23
• Mean 31.4 GHz sky brightness temperature(tbsky31)
• tnd23
• Sky infrared temperature(sky_ir_temp)
• base_time
• tnd31
• tknd
• Altitude above mean sea level(alt)

NSA/MWRP/C1 - Radiometer thermally unstable

Between Dec 21 and Dec 23 the external temperature dropped to - 38 C. This caused a 
problem with the stability of the noise diode mount temperature and consequent problem with 
calibration.

• Water vapor, total precipitable, derived from Tbright using stat. retrvl.(totalPrecipitableWater)
• Temperature, virtual, vert. prof. sfc-10km, fr. wtr. vap. dens. and temp. prof.(virtualTemperature)
• MET air temperature(temperature)
• Density, water vapor, prof. from sfc.-10 km, der. from Tbright stat. retrvl.(waterVaporDensity)
• Humidity, relative, prof. from sfc.-10km, from water vap. dens. and temp. prof.(relativeHumidity)
• Liquid water content, cloud, vert. prof. sfc.-10km, from Tbright stat. retrvl.(liquidWaterContent)
• Microwave brightness temperature(brightnessTemperature)
• Liquid water path, from brightness temperatures using statistical retrieval(liquidWaterPath)
• Liquid water path, from Tbright at 23.835 and 30.0 GHz only, using stat. retrvl.(liquidWaterPath2)
• Mixing ratio, water vap., vert. prof. sfc-10km, frm retr. water vap. dens. prof(waterVaporMixingRatio)
• Water vapor, tot. precipitable, from Tbright, 23.835 & 30.0 GHz, stat. retrvl.(totalPrecipitableWater2)
• Temperature, dew point, vert. prof. sfc-10km, from water vapor density prof.(dewpointTemperature)

NSA/MWRP/C1 - Radiometer thermally unstable

During January the radiometer was thermally unstable during several days of cold weather. 
The worst days of thermal instability were between Jan 12 and Jan 17.

• Water vapor, total precipitable, derived from Tbright using stat. retrvl.(totalPrecipitableWater)
• Temperature, virtual, vert. prof. sfc-10km, fr. wtr. vap. dens. and temp. prof.(virtualTemperature)
• MET air temperature(temperature)
• Density, water vapor, prof. from sfc.-10 km, der. from Tbright stat. retrvl.(waterVaporDensity)
• Liquid water content, cloud, vert. prof. sfc.-10km, from Tbright stat. retrvl.(liquidWaterContent)
• Microwave brightness temperature(brightnessTemperature)
• Liquid water path, from brightness temperatures using statistical retrieval(liquidWaterPath)
• Liquid water path, from Tbright at 23.835 and 30.0 GHz only, using stat. retrvl.(liquidWaterPath2)
• Mixing ratio, water vap., vert. prof. sfc-10km, frm retr. water vap. dens. prof(waterVaporMixingRatio)
• Water vapor, tot. precipitable, from Tbright, 23.835 & 30.0 GHz, stat. retrvl.(totalPrecipitableWater2)

NSA/MWRP/C1 - Hardware failure- Intermittent data

Data are intermittent during this time due to a failure of the analog board.
The calibration of V-band data may have slightly drifted due to power outages.

• Temperature, virtual, vert. prof. sfc-10km, fr. wtr. vap. dens. and temp. prof.(virtualTemperature)
• MET air temperature(temperature)
• Humidity, relative, prof. from sfc.-10km, from water vap. dens. and temp. prof.(relativeHumidity)
• Microwave brightness temperature(brightnessTemperature)
• Temperature, dew point, vert. prof. sfc-10km, from water vapor density prof.(dewpointTemperature)

NSA/MWRP/C1 - Thermal instability- TKnd test

During this time the radiometer was thermally unstable . The noise diode physical 
temperature had sudden drops of more than 5 degree in several ccasions between 2/1 and 2/11. On 
2/12 the radiometer temperature set point was lowered of about 10 degree as a test. On 
2/27 a new analog board was installed in the instrument. Data after 2/27 show a slight 
change in calibration.

• Water vapor, total precipitable, derived from Tbright using stat. retrvl.(totalPrecipitableWater)
• waterVaporDensityRmsError
• Temperature, virtual, vert. prof. sfc-10km, fr. wtr. vap. dens. and temp. prof.(virtualTemperature)
• MET air temperature(temperature)
• Density, water vapor, prof. from sfc.-10 km, der. from Tbright stat. retrvl.(waterVaporDensity)
• Humidity, relative, prof. from sfc.-10km, from water vap. dens. and temp. prof.(relativeHumidity)
• Liquid water content, cloud, vert. prof. sfc.-10km, from Tbright stat. retrvl.(liquidWaterContent)
• Microwave brightness temperature(brightnessTemperature)
• Liquid water path, from brightness temperatures using statistical retrieval(liquidWaterPath)
• Liquid water path, from Tbright at 23.835 and 30.0 GHz only, using stat. retrvl.(liquidWaterPath2)
• Mixing ratio, water vap., vert. prof. sfc-10km, frm retr. water vap. dens. prof(waterVaporMixingRatio)
• Water vapor, tot. precipitable, from Tbright, 23.835 & 30.0 GHz, stat. retrvl.(totalPrecipitableWater2)

NSA/MWRP/C1 - V-band Noise diode unstable

Sometimes between Jan and March 2007 the V-band noise diode started to be unstable. V-band 
channels during this period show large discrepancies with model computations. The 
problem was evident during the month of January. During February and March the problem was less 
visible, however measurement model comparisons show an increased bias. The instrument 
was calibrated with LN2 on March 15 and the calibration results showed a large drift in the 
calibration parameters.  The hardware failure will have consequences in the retrievals 
of temperature and relative humidity profiles. 

It is difficult to establish when the failure started. Disregard the V-band channels 
during this period. Vertical profiles of temperature and humidity are affected as well. Please 
note that this DQR only covers the 7 channels (brightness temperatures) in the V-band 
range (51 to 60 GHz). The 5 K-band channels (20-31 GHz) are not affected.

• Temperature, virtual, vert. prof. sfc-10km, fr. wtr. vap. dens. and temp. prof.(virtualTemperature)
• Density, water vapor, prof. from sfc.-10 km, der. from Tbright stat. retrvl.(waterVaporDensity)
• Humidity, relative, prof. from sfc.-10km, from water vap. dens. and temp. prof.(relativeHumidity)
• Microwave brightness temperature(brightnessTemperature)
• Mixing ratio, water vap., vert. prof. sfc-10km, frm retr. water vap. dens. prof(waterVaporMixingRatio)
• Temperature, dew point, vert. prof. sfc-10km, from water vapor density prof.(dewpointTemperature)

NSA/MWRP/C1 - V-band Noise diode failure

The LN2 calibration on 3/15 showed a large drift of the V-band calibration parameters. The 
radiometer was calibrated again in June and was sent out for repairs in July 2007.

Between 3/15 and 7/13 2007 the V-band data are incorrect and should be disregarded. The 
failure affects the retrieved vertical profiles of temperature and humidity as well.

Please note that the hardware failure affected the 7 V-band channels only (51-60 GHz). 
Channels in the frequency range between 20 and 30 GHz are not affected. Integrated liquid 
water (LWP) and water vapor (PWV) are not affected since they use K-band channels only.

• Temperature, virtual, vert. prof. sfc-10km, fr. wtr. vap. dens. and temp. prof.(virtualTemperature)
• MET air temperature(temperature)
• Density, water vapor, prof. from sfc.-10 km, der. from Tbright stat. retrvl.(waterVaporDensity)
• Humidity, relative, prof. from sfc.-10km, from water vap. dens. and temp. prof.(relativeHumidity)
• Microwave brightness temperature(brightnessTemperature)
• Mixing ratio, water vap., vert. prof. sfc-10km, frm retr. water vap. dens. prof(waterVaporMixingRatio)

NSA/MWRP/C1 - Spare radiometer installed

A spare radiometer was provided by Radiometrics while they try to fix our MWRP. The spare 
radiometer is of the same family as the one we have in Barrow and it will stay at the 
site until our radiometer is repaired.
A LN2 calibration will be performed next week.

• Pressure, level of free convection(levelFreeConvectionPres)
• Temperature, virtual, vert. prof. sfc-10km, fr. wtr. vap. dens. and temp. prof.(virtualTemperature)
• Pressure, lifting condensation level(liftingCondensationLevelPres)
• dataQualityFlags
• Pressure, equilibrium level(equilibriumLevelPres)
• Density, water vapor, at instrument height (1 or 2 m)(surfaceWaterVaporDensity)
• totalPrecipitableWater2RmsError
• Humidity, relative, prof. from sfc.-10km, from water vap. dens. and temp. prof.(relativeHumidity)
• Liquid water content, cloud, vert. prof. sfc.-10km, from Tbright stat. retrvl.(liquidWaterContent)
• wetWindowFlag
• Liquid water path, from Tbright at 23.835 and 30.0 GHz only, using stat. retrvl.(liquidWaterPath2)
• Height, equilibrium level(equilibriumLevel)
• infraredTemperature
• CAPE, Convective available potential energy(cape)
• time
• time_offset
• liquidWaterPathRmsError
• waterVaporDensityRmsError
• surface pressure(pressure)
• blackbodyTemperature
• Microwave brightness temperature(brightnessTemperature)
• Liquid water path, from brightness temperatures using statistical retrieval(liquidWaterPath)
• Mixing ratio, water vap., vert. prof. sfc-10km, frm retr. water vap. dens. prof(waterVaporMixingRatio)
• Altitude above mean sea level(alt)
• Pressure, barometric. at instrument height (1 or 2 m)(surfacePressure)
• Height, lifting condensation level(liftingCondensationLevel)
• Pressure, associated geometric height, at altitude, NGM model output(height)
• Height, level of free convection(levelFreeConvection)
• elevation
• liquidWaterContentRmsError
• Humidity, relative, at instrument height (1 or 2 m)(surfaceRelativeHumidity)
• liquidWaterPath2RmsError
• Temperature, dew point, vert. prof. sfc-10km, from water vapor density prof.(dewpointTemperature)
• Temperature, air, at instrument height (1 or 2 m)(surfaceTemperature)
• frequency
• temperatureRmsError
• Water vapor, total precipitable, derived from Tbright using stat. retrvl.(totalPrecipitableWater)
• MET air temperature(temperature)
• base_time
• Density, water vapor, prof. from sfc.-10 km, der. from Tbright stat. retrvl.(waterVaporDensity)
• totalPrecipitableWaterRmsError
• East longitude(lon)
• Height, cloud base, height where IR temp. matches retrieved temp. profile(cloudBaseHeight)
• North latitude(lat)
• azimuth
• Water vapor, tot. precipitable, from Tbright, 23.835 & 30.0 GHz, stat. retrvl.(totalPrecipitableWater2)

NSA/MWRP/C1 - Radiometer in mixed scanning-zenith mode

After installing the spare radiometer (D080409.2), the data started to be intermittent and 
the software froze several times. To test if the problem was due to the scanning 
procedure used with the other radiometer, the instrument was run with a zenith-only procedure at 
times and with the usual scanning procedure at restart. When restarted with the scanning 
procedure the software had problems, so it was decided to run the spare instrument only 
with the zenith-viewing mode until our instrument comes back.

The quality of the data should be unaffected. The only difference is that only data 
collected at 90 degree angle will be available until our instrument comes back.

• Pressure, level of free convection(levelFreeConvectionPres)
• Temperature, virtual, vert. prof. sfc-10km, fr. wtr. vap. dens. and temp. prof.(virtualTemperature)
• Pressure, lifting condensation level(liftingCondensationLevelPres)
• dataQualityFlags
• Pressure, equilibrium level(equilibriumLevelPres)
• Density, water vapor, at instrument height (1 or 2 m)(surfaceWaterVaporDensity)
• totalPrecipitableWater2RmsError
• Humidity, relative, prof. from sfc.-10km, from water vap. dens. and temp. prof.(relativeHumidity)
• Liquid water content, cloud, vert. prof. sfc.-10km, from Tbright stat. retrvl.(liquidWaterContent)
• wetWindowFlag
• Liquid water path, from Tbright at 23.835 and 30.0 GHz only, using stat. retrvl.(liquidWaterPath2)
• Height, equilibrium level(equilibriumLevel)
• infraredTemperature
• CAPE, Convective available potential energy(cape)
• time
• time_offset
• liquidWaterPathRmsError
• waterVaporDensityRmsError
• surface pressure(pressure)
• blackbodyTemperature
• Microwave brightness temperature(brightnessTemperature)
• Liquid water path, from brightness temperatures using statistical retrieval(liquidWaterPath)
• Mixing ratio, water vap., vert. prof. sfc-10km, frm retr. water vap. dens. prof(waterVaporMixingRatio)
• Altitude above mean sea level(alt)
• Pressure, barometric. at instrument height (1 or 2 m)(surfacePressure)
• Height, lifting condensation level(liftingCondensationLevel)
• Pressure, associated geometric height, at altitude, NGM model output(height)
• Height, level of free convection(levelFreeConvection)
• elevation
• liquidWaterContentRmsError
• Humidity, relative, at instrument height (1 or 2 m)(surfaceRelativeHumidity)
• liquidWaterPath2RmsError
• Temperature, dew point, vert. prof. sfc-10km, from water vapor density prof.(dewpointTemperature)
• Temperature, air, at instrument height (1 or 2 m)(surfaceTemperature)
• frequency
• temperatureRmsError
• Water vapor, total precipitable, derived from Tbright using stat. retrvl.(totalPrecipitableWater)
• MET air temperature(temperature)
• base_time
• Density, water vapor, prof. from sfc.-10 km, der. from Tbright stat. retrvl.(waterVaporDensity)
• totalPrecipitableWaterRmsError
• East longitude(lon)
• Height, cloud base, height where IR temp. matches retrieved temp. profile(cloudBaseHeight)
• North latitude(lat)
• azimuth
• Water vapor, tot. precipitable, from Tbright, 23.835 & 30.0 GHz, stat. retrvl.(totalPrecipitableWater2)

NSA/MWR/C1 - Spikes in air temperature readings

During this month there are occasional negative spikes in the Tkair variable. The problem 
may be corrosion in the temperature sensor or the infiltration of water from melting snow.
The dewblower was replaced and a new sensor installed

• tkair

NSA/MWRP/C1 - Intermittent data

A spare radiometer was installed a the site to substitute the malfunctioning radiometer 
(see DQRs D080409.2 and D080421.1). During this time the spare radiometer had problems 
starting and was stopping collection suddenly. Data during this time are very intermittent 
with large gaps.

• Pressure, level of free convection(levelFreeConvectionPres)
• Temperature, virtual, vert. prof. sfc-10km, fr. wtr. vap. dens. and temp. prof.(virtualTemperature)
• Pressure, lifting condensation level(liftingCondensationLevelPres)
• dataQualityFlags
• Pressure, equilibrium level(equilibriumLevelPres)
• Density, water vapor, at instrument height (1 or 2 m)(surfaceWaterVaporDensity)
• totalPrecipitableWater2RmsError
• Humidity, relative, prof. from sfc.-10km, from water vap. dens. and temp. prof.(relativeHumidity)
• Liquid water content, cloud, vert. prof. sfc.-10km, from Tbright stat. retrvl.(liquidWaterContent)
• wetWindowFlag
• Liquid water path, from Tbright at 23.835 and 30.0 GHz only, using stat. retrvl.(liquidWaterPath2)
• Height, equilibrium level(equilibriumLevel)
• infraredTemperature
• CAPE, Convective available potential energy(cape)
• time
• time_offset
• liquidWaterPathRmsError
• waterVaporDensityRmsError
• surface pressure(pressure)
• blackbodyTemperature
• Microwave brightness temperature(brightnessTemperature)
• Liquid water path, from brightness temperatures using statistical retrieval(liquidWaterPath)
• Mixing ratio, water vap., vert. prof. sfc-10km, frm retr. water vap. dens. prof(waterVaporMixingRatio)
• Altitude above mean sea level(alt)
• Pressure, barometric. at instrument height (1 or 2 m)(surfacePressure)
• Height, lifting condensation level(liftingCondensationLevel)
• Pressure, associated geometric height, at altitude, NGM model output(height)
• Height, level of free convection(levelFreeConvection)
• elevation
• liquidWaterContentRmsError
• Humidity, relative, at instrument height (1 or 2 m)(surfaceRelativeHumidity)
• liquidWaterPath2RmsError
• Temperature, dew point, vert. prof. sfc-10km, from water vapor density prof.(dewpointTemperature)
• Temperature, air, at instrument height (1 or 2 m)(surfaceTemperature)
• frequency
• temperatureRmsError
• Water vapor, total precipitable, derived from Tbright using stat. retrvl.(totalPrecipitableWater)
• MET air temperature(temperature)
• base_time
• Density, water vapor, prof. from sfc.-10 km, der. from Tbright stat. retrvl.(waterVaporDensity)
• totalPrecipitableWaterRmsError
• East longitude(lon)
• Height, cloud base, height where IR temp. matches retrieved temp. profile(cloudBaseHeight)
• North latitude(lat)
• azimuth
• Water vapor, tot. precipitable, from Tbright, 23.835 & 30.0 GHz, stat. retrvl.(totalPrecipitableWater2)

NSA/MWRP/C1 - Reprocessed: LN2 calibration

On 4/9 a spare radiometer was installed at the site. On 4/18 a LN2 calibration was 
conducted. Upon examination of the data it appeared that the LN2 calibration was generally 
successful, however the 30-GHz channel was not calibrated properly.
New calibration coefficients for all K-band channels were derived and data for the whole 
month should be reprocessed with these newly derived coefficients. I will provide the new 
configuration file.

An explanation of the effects of the poor calibration is given in the Instrument Mentor 
Monthly Summary report. The poor calibration affected the LWP in particular. Re-calibration 
will correct the problem.

Data reprocessed 20080610.

• Water vapor, total precipitable, derived from Tbright using stat. retrvl.(totalPrecipitableWater)
• Humidity, relative, prof. from sfc.-10km, from water vap. dens. and temp. prof.(relativeHumidity)
• Liquid water content, cloud, vert. prof. sfc.-10km, from Tbright stat. retrvl.(liquidWaterContent)
• Microwave brightness temperature(brightnessTemperature)
• Liquid water path, from brightness temperatures using statistical retrieval(liquidWaterPath)
• Liquid water path, from Tbright at 23.835 and 30.0 GHz only, using stat. retrvl.(liquidWaterPath2)
• Mixing ratio, water vap., vert. prof. sfc-10km, frm retr. water vap. dens. prof(waterVaporMixingRatio)
• Water vapor, tot. precipitable, from Tbright, 23.835 & 30.0 GHz, stat. retrvl.(totalPrecipitableWater2)

NSA/MWRP/C1 - Increased RF intereference

The spare radiometer experienced increased levels of RF interference. The interference is 
prominent on the 30-GHz channel and LWP retrievals that appear particularly noisy.

• Microwave brightness temperature(brightnessTemperature)
• Liquid water path, from brightness temperatures using statistical retrieval(liquidWaterPath)
• Liquid water path, from Tbright at 23.835 and 30.0 GHz only, using stat. retrvl.(liquidWaterPath2)

NSA/MWR/C1 - Missing surface air temperature data

Some wires in the dewblower were not correctly configured.

• tkair

NSA/MWRP/C1 - Reprocessed: LN2 calibrations applied

The V-band measurements were incorrect. The quantities affected were the temperature and 
humidity profiles.

The instrument was re-calibrated on July 18.  The new calibrations have been applied to 
the data for this time period.  The reprocessed data were archived in January 2009.

• Water vapor, total precipitable, derived from Tbright using stat. retrvl.(totalPrecipitableWater)
• Temperature, virtual, vert. prof. sfc-10km, fr. wtr. vap. dens. and temp. prof.(virtualTemperature)
• MET air temperature(temperature)
• Density, water vapor, prof. from sfc.-10 km, der. from Tbright stat. retrvl.(waterVaporDensity)
• Humidity, relative, prof. from sfc.-10km, from water vap. dens. and temp. prof.(relativeHumidity)
• Liquid water content, cloud, vert. prof. sfc.-10km, from Tbright stat. retrvl.(liquidWaterContent)
• Microwave brightness temperature(brightnessTemperature)
• Liquid water path, from brightness temperatures using statistical retrieval(liquidWaterPath)
• Liquid water path, from Tbright at 23.835 and 30.0 GHz only, using stat. retrvl.(liquidWaterPath2)
• Mixing ratio, water vap., vert. prof. sfc-10km, frm retr. water vap. dens. prof(waterVaporMixingRatio)
• Water vapor, tot. precipitable, from Tbright, 23.835 & 30.0 GHz, stat. retrvl.(totalPrecipitableWater2)
• Temperature, dew point, vert. prof. sfc-10km, from water vapor density prof.(dewpointTemperature)

NSA/MWRP/C1 - V-band noise diode failure

The V-band noise diode is showing signs of instability. Starting about August 5 the 
comparison of brightness temperatures with model showed an increased divergence resulting from 
a downward trend in the brightness temperatures of frequencies > 50 GHz.

Disregard brightness temperatures and retrieved products associated with the V-band 
channels. These include all profiles. Integrated water vapor and liquid water path are not 
affected.

• Pressure, level of free convection(levelFreeConvectionPres)
• Temperature, virtual, vert. prof. sfc-10km, fr. wtr. vap. dens. and temp. prof.(virtualTemperature)
• Height, lifting condensation level(liftingCondensationLevel)
• MET air temperature(temperature)
• Pressure, lifting condensation level(liftingCondensationLevelPres)
• Height, level of free convection(levelFreeConvection)
• Density, water vapor, prof. from sfc.-10 km, der. from Tbright stat. retrvl.(waterVaporDensity)
• Humidity, relative, prof. from sfc.-10km, from water vap. dens. and temp. prof.(relativeHumidity)
• Microwave brightness temperature(brightnessTemperature)
• Mixing ratio, water vap., vert. prof. sfc-10km, frm retr. water vap. dens. prof(waterVaporMixingRatio)
• Temperature, dew point, vert. prof. sfc-10km, from water vapor density prof.(dewpointTemperature)

SGP/MWR/C1 - Increased noise in 31.4 GHz channel

The 31.4 GHz channel has been showing an increased level of noise which results in 
increased noise in the LWP retrievals. The instrument is tipping and all other parameters seem 
to be in the range. The elevate noise started in May, but it seems to have become slightly 
worse after summer. After November the noise level seems to have gone back to normal.

• Mean 31.4 GHz sky brightness temperature(tbsky31)
• Water, liquid, total along line-of-sight path(liq)

NSA/MWRP/C1 - Incorrect V-band data

The V-band channels show a drift during this time.

• Pressure, level of free convection(levelFreeConvectionPres)
• Temperature, virtual, vert. prof. sfc-10km, fr. wtr. vap. dens. and temp. prof.(virtualTemperature)
• Height, lifting condensation level(liftingCondensationLevel)
• MET air temperature(temperature)
• Pressure, lifting condensation level(liftingCondensationLevelPres)
• Height, level of free convection(levelFreeConvection)
• Density, water vapor, prof. from sfc.-10 km, der. from Tbright stat. retrvl.(waterVaporDensity)
• Humidity, relative, prof. from sfc.-10km, from water vap. dens. and temp. prof.(relativeHumidity)
• Liquid water content, cloud, vert. prof. sfc.-10km, from Tbright stat. retrvl.(liquidWaterContent)
• Microwave brightness temperature(brightnessTemperature)
• Mixing ratio, water vap., vert. prof. sfc-10km, frm retr. water vap. dens. prof(waterVaporMixingRatio)

NSA/MWR/C1 - Incorrect brightness temperatures and retrievals

The brightness temperatures and retrieved PWV and LWP show a sudden jump and have values 
that are too high. The suddenly jump back to normal at around 1800 UTC. All other 
parameters seem reasonable so the cause of the jump may just be due to accumulation of either 
snow or melting ice on the radome.

• Mean 31.4 GHz sky brightness temperature(tbsky31)
• Water, liquid, total along line-of-sight path(liq)
• Total water vapor along LOS path(vap)
• 23.8 GHz sky brightness temperature(tbsky23)
• tkair

NSA/MWRP/C1 - Reprocessed: Negative bias in LWP

After the radiometer was installed at the site following extensive refurbishing the 
retrieved LWP had a large negative bias (~-0.07 mm). The calibration coefficients were modified 
and that resolved the problem. Data for February, March and part of April were 
reprocessed with the revised calibrations and archived in July.

• Water vapor, total precipitable, derived from Tbright using stat. retrvl.(totalPrecipitableWater)
• Microwave brightness temperature(brightnessTemperature)
• Liquid water path, from brightness temperatures using statistical retrieval(liquidWaterPath)
• Liquid water path, from Tbright at 23.835 and 30.0 GHz only, using stat. retrvl.(liquidWaterPath2)
• Water vapor, tot. precipitable, from Tbright, 23.835 & 30.0 GHz, stat. retrvl.(totalPrecipitableWater2)

NSA/MWR/C1 - RFI screening test

The instrument was covered with a shield to test the effect on the RF interference that is 
affecting the measurements since February. The test was performed on 4/15 and 4/16 for a 
few hours.

• Mean 31.4 GHz sky brightness temperature(tbsky31)
• Water, liquid, total along line-of-sight path(liq)
• 23.8 GHz sky brightness temperature(tbsky23)
• tnd23
• tknd
• tnd31
• tnd_nom23
• bb23
• tc23
• sky31
• tnd_nom31
• bb31
• actel
• tc31
• Sky infrared temperature(sky_ir_temp)
• sky23
• tkxc
• Total water vapor along LOS path(vap)
• Temperature, brightness, longwave(ir_temp)
• tkbb
• actaz
• bbn23
• wet_window
• bbn31
• tkair

NSA/MWR/C1 - High noise in 23.8-GHz channel

Starting approximately on February 13 the MWR experienced high level of noise in the 23.8 
GHz channel. The spikes became more prominent around Feb 17 and increased after that date 
as well. The cause of the interference was identified as the nearby MWRP on Oct 13 and 
the instruments were realigned.

• sky23
• Total water vapor along LOS path(vap)
• 23.8 GHz sky brightness temperature(tbsky23)

NSA/MWR/C1 - Intermittent air temperature readings

Starting on 5/23 the air temperature readings (tkair) were intermittent and had negative 
spikes

• tkair

NSA/MWR/C1 - Air temperature readings missing

The air temperature readings (tkair) dropped on 5/26. The signal was restored on 6/10.

• tkair

NSA/MWRP/C1 - Reprocessed: V-band channels too cold

The calibrations of 7/20 and 7/29 were slightly affected by high humidity at the site. As 
a result the V-band channels were calibrated too cold.

On 8/26 the mentor modified the configuration file and reinstated the calibration 
coefficients derived on 3/20/2009.

Data were reprocessed 20100118.

• Temperature, virtual, vert. prof. sfc-10km, fr. wtr. vap. dens. and temp. prof.(virtualTemperature)
• MET air temperature(temperature)
• Microwave brightness temperature(brightnessTemperature)

NSA/MWR/C1 - Elevated noise

The data have high noise levels.

• Mean 31.4 GHz sky brightness temperature(tbsky31)
• sky23
• Total water vapor along LOS path(vap)
• 23.8 GHz sky brightness temperature(tbsky23)
• sky31

NSA/MWRP/C1 - Reprocessed: LN2 calibration

The instrument was calibrated on 3/5/2010. These latest calibration coefficients have been 
applied to February data as well to mitigate the high bias in LWP observed in February.  
Reprocessed data were archived April 2010.

• Pressure, level of free convection(levelFreeConvectionPres)
• Height, lifting condensation level(liftingCondensationLevel)
• Temperature, virtual, vert. prof. sfc-10km, fr. wtr. vap. dens. and temp. prof.(virtualTemperature)
• Pressure, lifting condensation level(liftingCondensationLevelPres)
• Height, level of free convection(levelFreeConvection)
• Pressure, equilibrium level(equilibriumLevelPres)
• Liquid water content, cloud, vert. prof. sfc.-10km, from Tbright stat. retrvl.(liquidWaterContent)
• Liquid water path, from Tbright at 23.835 and 30.0 GHz only, using stat. retrvl.(liquidWaterPath2)
• Height, equilibrium level(equilibriumLevel)
• Temperature, dew point, vert. prof. sfc-10km, from water vapor density prof.(dewpointTemperature)
• Water vapor, total precipitable, derived from Tbright using stat. retrvl.(totalPrecipitableWater)
• Density, water vapor, prof. from sfc.-10 km, der. from Tbright stat. retrvl.(waterVaporDensity)
• Microwave brightness temperature(brightnessTemperature)
• Liquid water path, from brightness temperatures using statistical retrieval(liquidWaterPath)
• Mixing ratio, water vap., vert. prof. sfc-10km, frm retr. water vap. dens. prof(waterVaporMixingRatio)
• Water vapor, tot. precipitable, from Tbright, 23.835 & 30.0 GHz, stat. retrvl.(totalPrecipitableWater2)

NSA/MWRP/C1 - IRT readings bias

The MWRP IRT appeared to not be reaching its lower limit (-50 C / 223.15 K). The readings 
stayed around 230 K although the sky was clear. On 6/16 the site technicians noticed that 
the gold mirror was scratched and appeared to have a deposit on it. The mirror was 
replaced and on 6/17 the lens was cleaned. These actions solved the problem.

• infraredTemperature

NSA/MWR/C1 - Missing data

Data are missing and unrecoverable.

• Mean 31.4 GHz sky brightness temperature(tbsky31)
• East longitude(lon)
• tnd23
• tknd
• tnd_nom23
• bb31
• sky23
• Sky infrared temperature(sky_ir_temp)
• tkxc
• Total water vapor along LOS path(vap)
• Altitude above mean sea level(alt)
• tkbb
• time_offset
• wet_window
• bbn23
• base_time
• tkair
• North latitude(lat)
• Water, liquid, total along line-of-sight path(liq)
• 23.8 GHz sky brightness temperature(tbsky23)
• tnd31
• bb23
• tc23
• sky31
• tnd_nom31
• actel
• tc31
• Temperature, brightness, longwave(ir_temp)
• actaz
• bbn31

NSA/MWRP/C1 - Reprocessed: Incorrect calibration

The calibration of the MWRP drifted starting on September 21. The drift caused a negative 
LWP. On 10/21 I modified the calibration of the 30 GHz channel in an attempt to correct 
for the negative bias in LWP. The change in the calibration however caused an excessive 
increase in the PWV retrievals. The original calibration values were reinstated on 10/29. I 
then recomputed the temperature coefficients as well as the noise diode injection 
temperature from tip curves and uploaded the new values on Nov 15 2010. 

Reprocess the data from 9/21 to 11/15 with the newly computed coefficients.

Reprocessing completed 20110111.

• Water vapor, total precipitable, derived from Tbright using stat. retrvl.(totalPrecipitableWater)
• Density, water vapor, prof. from sfc.-10 km, der. from Tbright stat. retrvl.(waterVaporDensity)
• Humidity, relative, prof. from sfc.-10km, from water vap. dens. and temp. prof.(relativeHumidity)
• Liquid water content, cloud, vert. prof. sfc.-10km, from Tbright stat. retrvl.(liquidWaterContent)
• Microwave brightness temperature(brightnessTemperature)
• Liquid water path, from brightness temperatures using statistical retrieval(liquidWaterPath)
• Liquid water path, from Tbright at 23.835 and 30.0 GHz only, using stat. retrvl.(liquidWaterPath2)
• Mixing ratio, water vap., vert. prof. sfc-10km, frm retr. water vap. dens. prof(waterVaporMixingRatio)
• Water vapor, tot. precipitable, from Tbright, 23.835 & 30.0 GHz, stat. retrvl.(totalPrecipitableWater2)

NSA/MWRP/C1 - Calibration drift

The radiometer showed increased drift in the K-band calibration. Several attempts to 
correct for the drift did not return the expected result.  

Instrument was removed from service 20110201 and returned to vendor for repair.

Data are erratic; data use during the indicated time is not recommended.

• Water vapor, total precipitable, derived from Tbright using stat. retrvl.(totalPrecipitableWater)
• Temperature, virtual, vert. prof. sfc-10km, fr. wtr. vap. dens. and temp. prof.(virtualTemperature)
• Height, lifting condensation level(liftingCondensationLevel)
• Height, level of free convection(levelFreeConvection)
• Density, water vapor, prof. from sfc.-10 km, der. from Tbright stat. retrvl.(waterVaporDensity)
• Humidity, relative, prof. from sfc.-10km, from water vap. dens. and temp. prof.(relativeHumidity)
• Liquid water content, cloud, vert. prof. sfc.-10km, from Tbright stat. retrvl.(liquidWaterContent)
• Microwave brightness temperature(brightnessTemperature)
• Liquid water path, from brightness temperatures using statistical retrieval(liquidWaterPath)
• Liquid water path, from Tbright at 23.835 and 30.0 GHz only, using stat. retrvl.(liquidWaterPath2)
• Water vapor, tot. precipitable, from Tbright, 23.835 & 30.0 GHz, stat. retrvl.(totalPrecipitableWater2)

NSA/MWRP/C1 - Incorrect brightness temperatures

The radiometer was reinstalled on 4/3/2011 but the 30 GHz data immediately appeared 
extremely noisy. The problem appears related to noise diode instability.

• Pressure, level of free convection(levelFreeConvectionPres)
• Height, lifting condensation level(liftingCondensationLevel)
• Temperature, virtual, vert. prof. sfc-10km, fr. wtr. vap. dens. and temp. prof.(virtualTemperature)
• Pressure, lifting condensation level(liftingCondensationLevelPres)
• Height, level of free convection(levelFreeConvection)
• Pressure, equilibrium level(equilibriumLevelPres)
• Humidity, relative, prof. from sfc.-10km, from water vap. dens. and temp. prof.(relativeHumidity)
• Liquid water content, cloud, vert. prof. sfc.-10km, from Tbright stat. retrvl.(liquidWaterContent)
• Liquid water path, from Tbright at 23.835 and 30.0 GHz only, using stat. retrvl.(liquidWaterPath2)
• Height, equilibrium level(equilibriumLevel)
• Temperature, dew point, vert. prof. sfc-10km, from water vapor density prof.(dewpointTemperature)
• Water vapor, total precipitable, derived from Tbright using stat. retrvl.(totalPrecipitableWater)
• MET air temperature(temperature)
• Density, water vapor, prof. from sfc.-10 km, der. from Tbright stat. retrvl.(waterVaporDensity)
• Microwave brightness temperature(brightnessTemperature)
• Liquid water path, from brightness temperatures using statistical retrieval(liquidWaterPath)
• Mixing ratio, water vap., vert. prof. sfc-10km, frm retr. water vap. dens. prof(waterVaporMixingRatio)
• Water vapor, tot. precipitable, from Tbright, 23.835 & 30.0 GHz, stat. retrvl.(totalPrecipitableWater2)

NSA/MWRP/C1 - Reprocess: Incorrect calibration coefficients

The radiometer data need to be reprocessed with new calibrations.

• Pressure, level of free convection(levelFreeConvectionPres)
• Height, lifting condensation level(liftingCondensationLevel)
• Temperature, virtual, vert. prof. sfc-10km, fr. wtr. vap. dens. and temp. prof.(virtualTemperature)
• Pressure, lifting condensation level(liftingCondensationLevelPres)
• Height, level of free convection(levelFreeConvection)
• Pressure, equilibrium level(equilibriumLevelPres)
• Humidity, relative, prof. from sfc.-10km, from water vap. dens. and temp. prof.(relativeHumidity)
• Liquid water content, cloud, vert. prof. sfc.-10km, from Tbright stat. retrvl.(liquidWaterContent)
• Liquid water path, from Tbright at 23.835 and 30.0 GHz only, using stat. retrvl.(liquidWaterPath2)
• Height, equilibrium level(equilibriumLevel)
• Temperature, dew point, vert. prof. sfc-10km, from water vapor density prof.(dewpointTemperature)
• Water vapor, total precipitable, derived from Tbright using stat. retrvl.(totalPrecipitableWater)
• MET air temperature(temperature)
• Density, water vapor, prof. from sfc.-10 km, der. from Tbright stat. retrvl.(waterVaporDensity)
• Height, cloud base, height where IR temp. matches retrieved temp. profile(cloudBaseHeight)
• Microwave brightness temperature(brightnessTemperature)
• Liquid water path, from brightness temperatures using statistical retrieval(liquidWaterPath)
• Mixing ratio, water vap., vert. prof. sfc-10km, frm retr. water vap. dens. prof(waterVaporMixingRatio)
• Water vapor, tot. precipitable, from Tbright, 23.835 & 30.0 GHz, stat. retrvl.(totalPrecipitableWater2)

NSA/MWRP/C1 - Rapid calibration drift

The radiometer calibration was rapidly drifting. Brightness temperatures as well as 
retrievals are incorrect.

• Pressure, level of free convection(levelFreeConvectionPres)
• Height, lifting condensation level(liftingCondensationLevel)
• Temperature, virtual, vert. prof. sfc-10km, fr. wtr. vap. dens. and temp. prof.(virtualTemperature)
• Pressure, lifting condensation level(liftingCondensationLevelPres)
• Height, level of free convection(levelFreeConvection)
• Pressure, equilibrium level(equilibriumLevelPres)
• Liquid water content, cloud, vert. prof. sfc.-10km, from Tbright stat. retrvl.(liquidWaterContent)
• Liquid water path, from Tbright at 23.835 and 30.0 GHz only, using stat. retrvl.(liquidWaterPath2)
• Height, equilibrium level(equilibriumLevel)
• CAPE, Convective available potential energy(cape)
• Temperature, dew point, vert. prof. sfc-10km, from water vapor density prof.(dewpointTemperature)
• Water vapor, total precipitable, derived from Tbright using stat. retrvl.(totalPrecipitableWater)
• MET air temperature(temperature)
• Density, water vapor, prof. from sfc.-10 km, der. from Tbright stat. retrvl.(waterVaporDensity)
• Height, cloud base, height where IR temp. matches retrieved temp. profile(cloudBaseHeight)
• Microwave brightness temperature(brightnessTemperature)
• Liquid water path, from brightness temperatures using statistical retrieval(liquidWaterPath)
• Mixing ratio, water vap., vert. prof. sfc-10km, frm retr. water vap. dens. prof(waterVaporMixingRatio)
• Water vapor, tot. precipitable, from Tbright, 23.835 & 30.0 GHz, stat. retrvl.(totalPrecipitableWater2)

NSA/MWRP/C1 - Calibration temperature dependence

The calibration was showing a noticeable temperature dependence that was not corrected by 
the calibration coefficients. Between 2/26 and 3/23 the quality of the data and of the 
retrievals is degraded.

• Water vapor, total precipitable, derived from Tbright using stat. retrvl.(totalPrecipitableWater)
• Temperature, virtual, vert. prof. sfc-10km, fr. wtr. vap. dens. and temp. prof.(virtualTemperature)
• MET air temperature(temperature)
• Density, water vapor, prof. from sfc.-10 km, der. from Tbright stat. retrvl.(waterVaporDensity)
• Humidity, relative, prof. from sfc.-10km, from water vap. dens. and temp. prof.(relativeHumidity)
• Liquid water content, cloud, vert. prof. sfc.-10km, from Tbright stat. retrvl.(liquidWaterContent)
• Microwave brightness temperature(brightnessTemperature)
• Liquid water path, from brightness temperatures using statistical retrieval(liquidWaterPath)
• Liquid water path, from Tbright at 23.835 and 30.0 GHz only, using stat. retrvl.(liquidWaterPath2)
• Mixing ratio, water vap., vert. prof. sfc-10km, frm retr. water vap. dens. prof(waterVaporMixingRatio)
• Water vapor, tot. precipitable, from Tbright, 23.835 & 30.0 GHz, stat. retrvl.(totalPrecipitableWater2)

NSA/MWRP/C1 - Reprocessed: Incorrect calibration

The LN2 calibration was only partially successful, some the K-band channels did not 
calibrate properly. On 4/25 new coefficients were derived from tip curves and were uploaded. 

The data for 4/13-4/25 were reprocessed to apply the 4/25 calibrations.  Reprocessed data 
were archived in July 2012.

• Water vapor, total precipitable, derived from Tbright using stat. retrvl.(totalPrecipitableWater)
• Temperature, virtual, vert. prof. sfc-10km, fr. wtr. vap. dens. and temp. prof.(virtualTemperature)
• Density, water vapor, prof. from sfc.-10 km, der. from Tbright stat. retrvl.(waterVaporDensity)
• Liquid water content, cloud, vert. prof. sfc.-10km, from Tbright stat. retrvl.(liquidWaterContent)
• Microwave brightness temperature(brightnessTemperature)
• Liquid water path, from brightness temperatures using statistical retrieval(liquidWaterPath)
• Liquid water path, from Tbright at 23.835 and 30.0 GHz only, using stat. retrvl.(liquidWaterPath2)
• Mixing ratio, water vap., vert. prof. sfc-10km, frm retr. water vap. dens. prof(waterVaporMixingRatio)
• Water vapor, tot. precipitable, from Tbright, 23.835 & 30.0 GHz, stat. retrvl.(totalPrecipitableWater2)

NSA/MWRP/C1 - IRT data suspect

The IRT readings are mostly incorrect between 12/04/2012 and 11/20/2013.

• infraredTemperature