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.

• Total liquid water along LOS path(liq)
• bbn23
• 31.4 GHz sky brightness temperature(tbsky31)
• tkair
• tknd
• tnd_nom23
• wet_window
• Radiation, longwave, brightness temperature, 23.8 GHz(tbsky23)
• bbn31
• bb31
• tnd23
• tc23
• sky23
• tc31
• bb23
• tnd_nom31
• IR Brightness Temperature(sky_ir_temp)
• tnd31
• tkxc
• sky31
• Total water vapor along LOS path(vap)
• tkbb

• tknd
• tnd31
• wet_window
• tnd23
• tkair
• 31.4 GHz sky brightness temperature(tbsky31)
• tnd_nom23
• tnd_nom31
• tc23
• bb23
• bbn31
• Total water vapor along LOS path(vap)
• sky31
• Total liquid water along LOS path(liq)
• tkbb
• tc31
• Radiation, longwave, brightness temperature, 23.8 GHz(tbsky23)
• tkxc
• sky23
• bb31
• bbn23
• IR Brightness Temperature(sky_ir_temp)

• wet_window
• bbn31
• tkair
• sky23
• tnd23
• tnd31
• tknd
• bbn23
• tkxc
• tnd_nom31
• Radiation, longwave, brightness temperature, 23.8 GHz(tbsky23)
• tc31
• Total liquid water along LOS path(liq)
• tkbb
• sky31
• tc23
• time_offset
• bb31
• Total water vapor along LOS path(vap)
• bb23
• tnd_nom23
• 31.4 GHz sky brightness temperature(tbsky31)
• IR Brightness Temperature(sky_ir_temp)

• tc23
• tkbb
• Radiation, longwave, brightness temperature, 23.8 GHz(tbsky23)
• sky31
• 31.4 GHz sky brightness temperature(tbsky31)
• tkair
• tknd
• tnd23
• bbn31
• bb31
• Total liquid water along LOS path(liq)
• tkxc
• tnd31
• IR Brightness Temperature(sky_ir_temp)
• tnd_nom31
• sky23
• bbn23
• bb23
• Total water vapor along LOS path(vap)
• tnd_nom23
• tc31
• wet_window

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

SGP/MWR/B1  - 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.

• tknd
• tkxc

SGP/MWR/B4  - 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.

• tknd
• tkxc

SGP/MWR/B5  - 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.

• tknd
• tkxc

SGP/MWR/B6  - 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

• tkair

SGP/MWR/B1 - thermal instability

During periods of high ambient temperature, the instrument may have been thermally 
unstable.

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

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

SGP/MWR/B6  - thermal instability

During periods of high ambient temperature, the instrument may have been thermally 
unstable.

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

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

SGP/MWR/E14  - thermal instability

During periods of high ambient temperature, the instrument may have been thermally 
unstable.

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

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

SGP/MWR/B4 - 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

• tkair

SGP/MWR/B6 - Heater problem

When the heater/blower was replaced, the wet_window flag was constantly set high because 
the "moisture threshold voltage" value in the configuration file was not changed. The 
value was corrected for the new heater and the constant flagging stopped.

• wet_window

• wet_window

• wet_window

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.

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

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

• tc23
• tnd23I
• tkxc
• tknd
• tkbb
• wet_window
• tnd31I
• tnd_nom23
• tkair
• tnd31
• tc31
• tnd_nom31
• tnd23

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

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

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).

• liqtip
• vaptip
• tbsky23tip
• tbsky31tip

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

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

SGP/MWR/B4 - Heater problem

The heater does not appear to be operating properly when moisture is detected. The problem 
was corrected by adjusting the heater sensivity.

• wet_window

• wet_window

SGP/MWR/E14 - Reprocess: wrong retrievals

When MWR#04 was installed at EF14 (replacing MWR#33), out-of-date retrieval coefficients 
were used in the configuration file.
The correct coefficients were applied when the computer, software, and configuration file 
were upgraded.

• vaptip
• liqtip

• Total liquid water along LOS path(liq)
• Total water vapor along LOS path(vap)

• Total liquid water along LOS path(liq)
• Total water vapor along LOS path(vap)

• mean_liq_mwr
• mean_vap_mwr

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.

• liqtip
• vaptip

• mean_liq_mwr
• mean_vap_mwr

• Total water vapor along LOS path(vap)
• Total liquid water along LOS path(liq)

• Total water vapor along LOS path(vap)
• Total liquid water along LOS path(liq)

SGP/MWR/C1 - spare instrument

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

• time_offset
• tipsky23
• tipsky31
• tnd31I
• bbn31
• r23
• tnd_nom23
• tkair
• lon
• actaz
• tbsky31tip
• lat
• tnd23
• tc23
• actel
• liqtip
• tnd23I
• tbsky23tip
• tkxc
• tknd
• tkbb
• wet_window
• bb23
• tnd31
• tc31
• vaptip
• alt
• bbn23
• r31
• tnd_nom31
• base_time
• bb31

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

SGP/MWR/E14 - computer problem

The computer was operating sporadically, requiring frequent reboots and resulting in 
periods of missing data. A warranty replacement of the motherboard corrected the problem.

• r31
• liqtip
• tnd_nom23
• actaz
• tnd_nom31
• wet_window
• tkxc
• bb23
• r23
• tc23
• tnd23I
• lat
• vaptip
• tkbb
• bbn31
• tc31
• tnd23
• tknd
• tipsky31
• alt
• tkair
• tnd31I
• tbskytip23
• time_offset
• bbn23
• base_time
• tipsky23
• bb31
• tnd31
• lon
• tbskytip31
• actel

• Raw data stream - documentation not supported

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

SGP/MWR/C1 - REPROCESS - Revised Retrieval Coefficients

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

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

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

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

PWV_MONORTM = 0.9695 * PWV_ROSENKRANZ
LWP_MONORTM = 1.026  * LWP_ROSENKRANZ

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

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

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

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

• Total liquid water along LOS path(liq)
• Total water vapor along LOS path(vap)

• liqtip
• vaptip

• mean_liq_mwr
• mean_vap_mwr

• Total water vapor along LOS path(vap)
• Total liquid water along LOS path(liq)

• Total water vapor along LOS path(vap)
• Total liquid water along LOS path(liq)

• Total water vapor along LOS path(vap)
• Total liquid water along LOS path(liq)

SGP/MWR/B1 - Reprocess: Revised Retrieval Coefficients

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

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

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

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

PWV_MONORTM = 0.9695 * PWV_ROSENKRANZ
LWP_MONORTM = 1.026  * LWP_ROSENKRANZ

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

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

• Total water vapor along LOS path(vap)
• Total liquid water along LOS path(liq)

• Total water vapor along LOS path(vap)
• Total liquid water along LOS path(liq)

• vaptip
• liqtip

• Total liquid water along LOS path(liq)
• Total water vapor along LOS path(vap)

• mean_vap_mwr
• mean_liq_mwr

SGP/MWR/B4 - Reprocess: Revised Retrieval Coefficients

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

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

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

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

PWV_MONORTM = 0.9695 * PWV_ROSENKRANZ
LWP_MONORTM = 1.026  * LWP_ROSENKRANZ

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

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

• Total water vapor along LOS path(vap)
• Total liquid water along LOS path(liq)

• vaptip
• liqtip

• mean_vap_mwr
• mean_liq_mwr

• Total water vapor along LOS path(vap)
• Total liquid water along LOS path(liq)

• Total water vapor along LOS path(vap)
• Total liquid water along LOS path(liq)

SGP/MWR/B5 - Reprocess: Revised Retrieval Coefficients

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

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

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

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

PWV_MONORTM = 0.9695 * PWV_ROSENKRANZ
LWP_MONORTM = 1.026  * LWP_ROSENKRANZ

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

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

• Total water vapor along LOS path(vap)
• Total liquid water along LOS path(liq)

• Total liquid water along LOS path(liq)
• Total water vapor along LOS path(vap)

• Total water vapor along LOS path(vap)
• Total liquid water along LOS path(liq)

• mean_liq_mwr
• mean_vap_mwr

• liqtip
• vaptip

SGP/MWR/B6 - Reprocess: Revised Retrieval Coefficients

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

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

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

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

PWV_MONORTM = 0.9695 * PWV_ROSENKRANZ
LWP_MONORTM = 1.026  * LWP_ROSENKRANZ

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

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

• Total water vapor along LOS path(vap)
• Total liquid water along LOS path(liq)

• Total water vapor along LOS path(vap)
• Total liquid water along LOS path(liq)

• vaptip
• liqtip

• Total water vapor along LOS path(vap)
• Total liquid water along LOS path(liq)

• mean_vap_mwr
• mean_liq_mwr

SGP/MWR/E14 - Reprocess: Revised Retrieval Coefficients

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

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

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

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

PWV_MONORTM = 0.9695 * PWV_ROSENKRANZ
LWP_MONORTM = 1.026  * LWP_ROSENKRANZ

The Rosenkranz-based retrieval coefficients became active at SGP.E14 
20020416.0000.  The MONORTM-based retrieval coefficients became active 
at SGP.E14 20050628.2300.

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.

• vaptip
• liqtip

• Total liquid water along LOS path(liq)
• Total water vapor along LOS path(vap)

• Total liquid water along LOS path(liq)
• Total water vapor along LOS path(vap)

• mean_liq_mwr
• mean_vap_mwr

SGP/MWR/E14 - Reprocess: thermal instability

During periods of high ambient temperature, the instrument may have been thermally 
unstable. The problem was corrected by increasing the RF deck temperature from 50 to 56 C.

The data will need to be reprocessed with calibration coefficients derived after the 
reference temperature, tkmx, was adjusted.

• tbskytip23
• vaptip
• liqtip
• tbskytip31

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

SGP/MWR/B1 - thermal instability

During periods of high ambient temperature, the instrument may have been thermally 
unstable. The problem was corrected by increasing the RF deck temperature from 50 to 52 C.

• vaptip
• liqtip
• tbskytip31
• tbskytip23

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

SGP/MWR/B1 - Reprocess: mixer temp adjustment

The RF deck temperature was increased from 50 to 52 C to prevent thermal instability in 
summer.  This resulted in a change in the calibration.  The data need to be reprocessed 
with the calibration coefficients that were automatically derived after the reference 
temperature, tkmx, was adjusted.

• tnd_nom31
• tnd31
• tc31
• tnd23
• tc23
• liqtip
• tbskytip31
• tbskytip23
• vaptip
• tnd_nom23

• Total liquid water along LOS path(liq)
• 31.4 GHz sky brightness temperature(tbsky31)
• tc23
• Radiation, longwave, brightness temperature, 23.8 GHz(tbsky23)
• tc31
• tnd31
• Total water vapor along LOS path(vap)
• tnd_nom23
• tnd_nom31
• tnd23

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.

• vap_sdev
• Temperature, brightness, longwave(ir_temp)
• number_obs_averaged
• 23tbsky
• liq_sdev
• prob_slope_change
• tbsky23_sdev
• ir_temp_sdev
• water_flag_fraction
• tbsky31_sdev
• Total water vapor along LOS path(vap)
• prob_outlier
• 31tbsky
• water_flag
• prob_level_change
• Radiation, longwave, brightness temperature, 23.8 GHz(tbsky23)
• Total liquid water along LOS path(liq)
• 31.4 GHz sky brightness temperature(tbsky31)

• tipsky23
• tipsky31
• tnd31I
• r23
• bbn31
• tnd_nom23
• tkair
• tbsky31tip
• tnd23
• tc23
• liqtip
• tnd23I
• tbsky23tip
• tknd
• tkbb
• tkxc
• wet_window
• bb23
• tnd31
• tc31
• vaptip
• bbn23
• r31
• tnd_nom31
• bb31

• 31.4 GHz sky brightness temperature(tbsky31)
• 31tbsky
• dlm_flag_fraction
• Radiation, longwave, brightness temperature, 23.8 GHz(tbsky23)
• water_flag_periods
• vap_sdev
• Total water vapor along LOS path(vap)
• 23tbsky
• tbsky31_sdev
• Total liquid water along LOS path(liq)
• ir_temp_sdev
• liq_sdev
• tbsky23_sdev
• water_flag_fraction
• Temperature, brightness, longwave(ir_temp)
• dlm_flag_periods

• wet_window
• bbn31
• tkair
• sky23
• tnd23
• tnd31
• tknd
• bbn23
• tkxc
• tnd_nom31
• tc31
• Radiation, longwave, brightness temperature, 23.8 GHz(tbsky23)
• Total liquid water along LOS path(liq)
• tkbb
• sky31
• tc23
• bb31
• Total water vapor along LOS path(vap)
• bb23
• tnd_nom23
• 31.4 GHz sky brightness temperature(tbsky31)
• IR Brightness Temperature(sky_ir_temp)

SGP/MWR/B1 - 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 9/13/2005 at 21:25. As a consequence 
of this upgrade, the tip curve frequency increased. The tip cycle time decreased from 
~60s to ~50s.

• tnd31
• bbn23
• tc23
• tknd
• tbskytip31
• liqtip
• vaptip
• r23
• tipsky23
• bb23
• tnd_nom31
• bbn31
• tc31
• tkbb
• tnd23
• tkxc
• tbskytip23
• r31
• tkair
• tnd23I
• tnd_nom23
• bb31
• tnd31I
• tipsky31

• Total liquid water along LOS path(liq)
• tkair
• sky23
• tc23
• bbn23
• tc31
• bb23
• tnd31
• Total water vapor along LOS path(vap)
• tnd_nom31
• tknd
• 31.4 GHz sky brightness temperature(tbsky31)
• IR Brightness Temperature(sky_ir_temp)
• bbn31
• Radiation, longwave, brightness temperature, 23.8 GHz(tbsky23)
• sky31
• tkbb
• bb31
• tnd_nom23
• tkxc
• Temperature, brightness, longwave(ir_temp)
• tnd23

SGP/MWR/B4 - 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 9/13/2005. As a consequence of this 
upgrade, the tip curve frequency increased. The tip cycle time decreased from ~60s to ~50s.

• tbskytip23
• bbn31
• liqtip
• tc31
• tkxc
• tnd_nom31
• bb23
• tnd31I
• bb31
• tnd31
• tnd23I
• tkair
• tipsky23
• r31
• tnd_nom23
• tc23
• tbskytip31
• vaptip
• tnd23
• tknd
• tkbb
• r23
• tipsky31
• bbn23

• tnd23
• tc23
• sky23
• Total liquid water along LOS path(liq)
• tc31
• bbn23
• bb23
• tnd_nom31
• 31.4 GHz sky brightness temperature(tbsky31)
• tkair
• tknd
• IR Brightness Temperature(sky_ir_temp)
• tnd31
• tnd_nom23
• Temperature, brightness, longwave(ir_temp)
• sky31
• tkxc
• Total water vapor along LOS path(vap)
• Radiation, longwave, brightness temperature, 23.8 GHz(tbsky23)
• tkbb
• bbn31
• bb31

SGP/MWR/B5 - 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 9/13/2005. As a consequence of this 
upgrade, the tip curve frequency increased. The tip cycle time decreased from ~60s to ~50s.

• bb31
• sky23
• tc31
• Radiation, longwave, brightness temperature, 23.8 GHz(tbsky23)
• sky31
• bbn23
• tnd23
• tkxc
• Total liquid water along LOS path(liq)
• Temperature, brightness, longwave(ir_temp)
• tnd_nom23
• bbn31
• tkair
• 31.4 GHz sky brightness temperature(tbsky31)
• tknd
• tnd31
• bb23
• IR Brightness Temperature(sky_ir_temp)
• Total water vapor along LOS path(vap)
• tc23
• tnd_nom31
• tkbb

• bb31
• liqtip
• bbn31
• vaptip
• tc31
• tnd23I
• tnd31I
• tnd31
• tipsky31
• bb23
• tbskytip23
• tnd_nom31
• tnd23
• r31
• bbn23
• tknd
• tc23
• tipsky23
• tbskytip31
• tkxc
• tkair
• tkbb
• tnd_nom23
• r23

SGP/MWR/B6 - 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 9/23/2005. As a consequence of this 
upgrade, the tip curve frequency increased. The tip cycle time decreased from ~60s to ~50s.

• Total water vapor along LOS path(vap)
• 31.4 GHz sky brightness temperature(tbsky31)
• tnd_nom23
• IR Brightness Temperature(sky_ir_temp)
• Temperature, brightness, longwave(ir_temp)
• tkbb
• tc23
• tc31
• sky31
• tnd31
• tkxc
• tnd_nom31
• bbn31
• bb23
• Radiation, longwave, brightness temperature, 23.8 GHz(tbsky23)
• Total liquid water along LOS path(liq)
• tknd
• tkair
• tnd23
• bbn23
• sky23
• bb31

• tnd23I
• tknd
• tkxc
• tnd_nom23
• tipsky23
• bb31
• tc23
• tbskytip31
• tkair
• tnd31
• tkbb
• bbn23
• r23
• bb23
• tnd23
• vaptip
• tipsky31
• tbskytip23
• tnd_nom31
• r31
• tc31
• bbn31
• tnd31I
• liqtip

SGP/MWR/E14 - New software version (4.15) installed

A problem began with the installation of MWR.EXE version 4.12 in May 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 8/1/2005. As a consequence of this 
upgrade, the tip curve frequency increased. The tip cycle time decreased from ~60s to ~50s.

• vaptip
• r31
• tkbb
• liqtip
• bbn31
• tnd_nom23
• tc31
• tnd23
• tnd_nom31
• tknd
• tipsky31
• bb23
• tkxc
• tkair
• tnd31I
• tbskytip23
• r23
• tc23
• bbn23
• tnd23I
• tipsky23
• bb31
• tnd31
• tbskytip31

• Total liquid water along LOS path(liq)
• tknd
• Radiation, longwave, brightness temperature, 23.8 GHz(tbsky23)
• bbn23
• 31.4 GHz sky brightness temperature(tbsky31)
• bb23
• tnd23
• Total water vapor along LOS path(vap)
• sky23
• tkair
• tc23
• IR Brightness Temperature(sky_ir_temp)
• bbn31
• tnd31
• tkbb
• bb31
• tnd_nom31
• tnd_nom23
• sky31
• tc31
• tkxc

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.

• tc23
• liqtip
• tnd23I
• tbsky23tip
• tipsky23
• tipsky31
• tkxc
• tknd
• tkbb
• tnd31I
• r23
• bbn31
• tnd_nom23
• bb23
• tkair
• tnd31
• tc31
• vaptip
• tbsky31tip
• bbn23
• r31
• tnd_nom31
• bb31
• tnd23

• bbn23
• tkxc
• tnd_nom31
• tc31
• Radiation, longwave, brightness temperature, 23.8 GHz(tbsky23)
• Total liquid water along LOS path(liq)
• tkbb
• sky31
• tc23
• bb31
• bbn31
• Total water vapor along LOS path(vap)
• tkair
• bb23
• tnd_nom23
• sky23
• 31.4 GHz sky brightness temperature(tbsky31)
• tnd23
• IR Brightness Temperature(sky_ir_temp)
• tnd31
• tknd

SGP/MWR/E14 - Instrument maintenance

The MWR teflon cover was replaced with an old one that is not hydrophobic. This affected 
the measurements during and immediately after rain. A new teflon window was placed on 3/29

• r31
• liqtip
• tnd_nom23
• actaz
• tnd_nom31
• wet_window
• tkxc
• bb23
• r23
• tc23
• tnd23I
• lat
• vaptip
• tkbb
• bbn31
• tc31
• tnd23
• tknd
• tipsky31
• alt
• tkair
• tnd31I
• tbskytip23
• time_offset
• bbn23
• base_time
• tipsky23
• bb31
• tnd31
• lon
• tbskytip31
• actel

• Raw data stream - documentation not supported

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

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

SGP/MWR/B4 - 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 BF4 were applied when the software was upgraded to ver. 4.14 
and the configuration file was updated.

• vaptip
• liqtip

• mean_vap_mwr
• mean_liq_mwr

• Total water vapor along LOS path(vap)
• Total liquid water along LOS path(liq)

• Total water vapor along LOS path(vap)
• Total liquid water along LOS path(liq)

SGP/MWR/B5 - 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 BF5 were applied when the software was upgraded to ver. 4.14 
and the configuration file was updated.

• Total liquid water along LOS path(liq)
• Total water vapor along LOS path(vap)

• Total water vapor along LOS path(vap)
• Total liquid water along LOS path(liq)

• mean_liq_mwr
• mean_vap_mwr

• liqtip
• vaptip

SGP/MWR/B6  - 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 BF6 were applied when the software was upgraded to ver. 4.14 
and the configuration file was updated.

• Total water vapor along LOS path(vap)
• Total liquid water along LOS path(liq)

• Total water vapor along LOS path(vap)
• Total liquid water along LOS path(liq)

• vaptip
• liqtip

• mean_vap_mwr
• mean_liq_mwr

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

• tkair

SGP/MWR/B5 - Mixer temp unstable

The radiometer mixer temperature was unstable during this time interval. The instability 
will slightly affect calibration.  On 8/21, the instrument was sent to the vendor for 
repair.

June and July data are suspect, the calibration may be slightly incorrect. August data 
should not be used.

• sky23
• tc31
• Radiation, longwave, brightness temperature, 23.8 GHz(tbsky23)
• sky31
• tnd23
• tkxc
• Total liquid water along LOS path(liq)
• tnd_nom23
• 31.4 GHz sky brightness temperature(tbsky31)
• tnd31
• tknd
• Total water vapor along LOS path(vap)
• tnd_nom31
• tc23

• liqtip
• vaptip
• tc31
• tnd23I
• tnd31I
• tnd31
• tipsky31
• tbskytip23
• tnd_nom31
• tnd23
• r31
• tknd
• tc23
• tbskytip31
• tipsky23
• tkxc
• tnd_nom23
• r23

SGP/MWR/B1 - Reprocessed: Corrected calibration

The radiometer was thermally unstable. Calibration coefficients for the time interval were 
re-derived after screening for bad values of TKxc and the data were reprocessed.  
Reprocessed MWRLOS data were archived January 2007.  MWRTIP data will not be reprocessed.

• tnd31
• tc23
• tknd
• liqtip
• tbskytip31
• vaptip
• r23
• tipsky23
• tnd_nom31
• tc31
• tnd23
• tkxc
• tbskytip23
• r31
• tnd23I
• tnd_nom23
• tnd31I
• tipsky31

• Raw data stream - documentation not supported

• tc23
• tc31
• tnd31
• Total water vapor along LOS path(vap)
• tnd_nom31
• tknd
• 31.4 GHz sky brightness temperature(tbsky31)
• Radiation, longwave, brightness temperature, 23.8 GHz(tbsky23)
• tnd_nom23
• tkxc
• tnd23

SGP/MWR/B6 - Reprocessed: Corrected calibration

The instrument was overheating so the radiometer temperature set point was increased from 
52 C to 56.5 C. The period between 7/20 and 7/22 has been reprocessed with corrected 
calibration coefficients.  Reprocessed MWRLOS data were archived January 2007.  MWRTIP data 
will not be reprocessed.

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

• tknd
• tkxc
• bb31
• tc23
• tkair
• tkbb
• bbn23
• alt
• r23
• bb23
• lon
• tipsky31
• r31
• base_time
• bbn31
• tnd23I
• tnd_nom23
• tipsky23
• tbskytip31
• actaz
• tnd31
• wet_window
• lat
• tnd23
• vaptip
• tbskytip23
• tnd_nom31
• time_offset
• tc31
• actel
• tnd31I
• liqtip

SGP/MWR/B6 - Reprocessed: Corrected calibration

The instrument was overheating so the radiometer temperature set point was increased from 
56.3 C to 57.8 C.  The data have been reprocessed with corrected calibration 
coefficients.  Reprocessed MWRLOS data were archived January 2007.  MWRTIP data will not be 
reprocessed.

• Total water vapor along LOS path(vap)
• 31.4 GHz sky brightness temperature(tbsky31)
• tnd_nom23
• tc23
• tc31
• tnd31
• tkxc
• tnd_nom31
• Radiation, longwave, brightness temperature, 23.8 GHz(tbsky23)
• Total liquid water along LOS path(liq)
• tknd
• tnd23

• tnd23I
• tknd
• tkxc
• tnd_nom23
• tipsky23
• tbskytip31
• tc23
• tnd31
• r23
• tnd23
• vaptip
• tbskytip23
• tipsky31
• tnd_nom31
• r31
• tc31
• tnd31I
• liqtip

SGP/MWR/E14 - Radiometer testing

The radiometer was removed and taken inside for testing

• r31
• liqtip
• tnd_nom23
• actaz
• tnd_nom31
• wet_window
• tkxc
• bb23
• r23
• tc23
• tnd23I
• lat
• vaptip
• tkbb
• bbn31
• tc31
• tnd23
• tknd
• tipsky31
• alt
• tkair
• tnd31I
• tbskytip23
• time_offset
• bbn23
• base_time
• tipsky23
• bb31
• tnd31
• lon
• tbskytip31
• actel

• Raw data stream - documentation not supported

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

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

• wet_window

• wet_window

• wet_window

SGP/MWR/E14 - Power supply failure

On 3/20 the instrument suffered a power supply failure and was removed for repairs

• r31
• liqtip
• tnd_nom23
• actaz
• tnd_nom31
• wet_window
• bb23
• tkxc
• r23
• tc23
• tnd23I
• lat
• vaptip
• tkbb
• bbn31
• tc31
• tnd23
• tknd
• tipsky31
• alt
• tkair
• tnd31I
• tbskytip23
• time_offset
• bbn23
• base_time
• tipsky23
• bb31
• tnd31
• lon
• tbskytip31
• actel

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

SGP/MWR/B1 - 23.8-GHz brightness temperature slightly high

The radiometer was refurbished and tested at the central facility in 2007. During testing 
the 23.8-GHz brightness temperature was found to be about 1.5 K higher than the 
measurements of the C1 radiometer. 

On 6/19/07 the radiometer was installed at BF1. A comparison with model calculation showed 
that the measured 23.8-GHz brightness temperature is slightly higher than the model. 
This offset will affect the PWV retrieval that is on an average about 1.3 mm higher than the 
radiosonde measurements. The rms error of the retrieved PWV is about 1 mm higher than 
specified in the netcdf file.

On 10/16/2009 the radiometer was removed because of shut down of the boundary facility.

• Total water vapor along LOS path(vap)
• Radiation, longwave, brightness temperature, 23.8 GHz(tbsky23)
• 23tbsky

• vaptip
• tbskytip23

• Radiation, longwave, brightness temperature, 23.8 GHz(tbsky23)
• Total water vapor along LOS path(vap)

SGP/MWR/C1 - Noisy data

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

• liqtip
• vaptip
• tbsky23tip
• tbsky31tip
• tipsky23
• bbn23
• tipsky31
• bbn31
• bb23
• bb31

• bbn23
• bb23
• sky23
• 31.4 GHz sky brightness temperature(tbsky31)
• Radiation, longwave, brightness temperature, 23.8 GHz(tbsky23)
• Total liquid water along LOS path(liq)
• sky31
• bb31
• Total water vapor along LOS path(vap)
• bbn31

SGP/MWR/E14 - Bias in 23.8-GHz measurements

Since the instrument was returned after a power supply failure the 23.8-GHz channel is 
constantly 3 K higher than the other co-located radiometer (C1). Since the instrument was 
just returned after extensive refurbishing at the manufacturer the cause of the bias is not 
clear.

• tbskytip23
• vaptip

• Radiation, longwave, brightness temperature, 23.8 GHz(tbsky23)
• Total water vapor along LOS path(vap)

SGP/MWR/B6 - Incorrect rain flag

The rain flag indicator is coming up too often. On 9/11 the SGP technicians checked and 
adjusted the rain sensor sensitivity. The operation seemed successful, bu on 9/18 the flag 
indicator came back up and stayed on too much since.

• wet_window

• wet_window

SGP/MWR/B5 - Intermittent missing data

Starting on 9/2/07 data have been intermittent due to frequent software crash. Large 
chunks (several days in duration) of data are missing. In March 2008 the fiber optics 
connections were checked and several faulty points were identified. The connections were 
repaired. Since then the instances of software crashes are much reduced.

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

• actel
• liqtip
• vaptip
• tc31
• tnd31
• tipsky31
• tbskytip23
• bbn23
• r31
• tbskytip31
• tkxc
• alt
• tnd_nom23
• r23
• lon
• bb31
• bbn31
• tnd23I
• tnd31I
• bb23
• wet_window
• tnd_nom31
• base_time
• tnd23
• tknd
• tc23
• time_offset
• tipsky23
• actaz
• tkair
• tkbb
• lat

SGP/MWR/C1 - Reprocess: Radiometer reinstalled- Please reprocess

After the radiometer was reinstalled it had to update the calibration coefficients.
Data will be reprocessed

• Total water vapor along LOS path(vap)
• 31tbsky
• Radiation, longwave, brightness temperature, 23.8 GHz(tbsky23)
• Total liquid water along LOS path(liq)
• 23tbsky
• 31.4 GHz sky brightness temperature(tbsky31)

• tc23
• liqtip
• tbsky23tip
• tipsky23
• tipsky31
• tnd_nom23
• tnd31
• tc31
• vaptip
• tbsky31tip
• tnd_nom31
• tnd23

• tnd_nom31
• tc31
• Radiation, longwave, brightness temperature, 23.8 GHz(tbsky23)
• Total liquid water along LOS path(liq)
• tc23
• Total water vapor along LOS path(vap)
• tnd_nom23
• 31.4 GHz sky brightness temperature(tbsky31)
• tnd23
• tnd31

SGP/MWR/B1 - Calibration failure

The radiometer suddenly stopped performing successful tip curve calibrations. Brightness 
temperatures are inaccurate during this time. The instrument was removed from service 
20071126.  Reprocessing is not possible.

• tnd31
• tc23
• tbskytip31
• vaptip
• r23
• tipsky23
• tnd_nom31
• tc31
• tnd23
• tbskytip23
• r31
• tnd23I
• tnd31I
• tnd_nom23
• tipsky31

• sky23
• tc23
• tc31
• tnd31
• Total water vapor along LOS path(vap)
• tnd_nom31
• 31.4 GHz sky brightness temperature(tbsky31)
• Radiation, longwave, brightness temperature, 23.8 GHz(tbsky23)
• sky31
• tnd_nom23
• tnd23

SGP/MWR/B6 - Incorrect mixer kinetic temperature

The mixer kinetic temperature values are incorrect. The mixer temp sensor was on an open 
circuit.

This is a diagnostic variable. The noise diode mount temperature Tknd can be used to 
monitor the thermal stabilization of the instrument

• tkxc

• tkxc

SGP/MWR/C1 - Missing data

Data are missing and unrecoverable.

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

SGP/MWR/B5 - Some rain events flagged

March 18 there was a strong rain event. During this time the brightness temperatures where 
> 100 K due to water accumulating on the radiometer, however the wet window flag 
indicator was not tripped.  Users should not rely on the wet window flag to screen 
rain-contaminated data.  Instead, apply a brightness temperature threshold of 100 K instead to both 
channels.

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

• tbskytip31
• tbskytip23
• liqtip
• vaptip
• wet_window

SGP/MWR/B6 - Reprocessed: Re-calibration

There was a slight change in the calibration of the instrument after it recovered from a 
data outage. 

Data were reprocessed with the following calibration coefficients:
Tnd23_nom = 238.29; Tc23 = 0.024
Tnd31_nom = 221.78; Tc31 = 0.013

The reprocessed data were archived June 2008.

• Radiation, longwave, brightness temperature, 23.8 GHz(tbsky23)
• Total water vapor along LOS path(vap)
• Total liquid water along LOS path(liq)
• 31.4 GHz sky brightness temperature(tbsky31)
• tnd_nom23
• tc23
• tc31
• tnd_nom31

• vaptip
• tbskytip23
• tnd_nom23
• tnd_nom31
• tbskytip31
• tc23
• tc31
• liqtip

SGP/MWR/B4 - Missing data

Data are missing and unrecoverable.

• actaz
• bbn31
• tc31
• lon
• tnd31I
• tipsky23
• tkair
• actel
• tkbb
• tknd
• time_offset
• bbn23
• tbskytip23
• liqtip
• base_time
• tkxc
• tnd_nom31
• bb23
• bb31
• tnd31
• tnd23I
• lat
• r31
• alt
• tnd_nom23
• tc23
• tbskytip31
• vaptip
• tnd23
• r23
• wet_window
• tipsky31

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

SGP/MWR/B5 - Missing data

Data are missing and unrecoverable.

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

SGP/MWR/B1 - Thermal instability-- Missing data

The radiometer had problem keeping the thermal stabilization when the ambient temperature 
exceeded 34.5 degree C. Data are missing during the times indicated.

• tc23
• tknd
• base_time
• wet_window
• tipsky23
• lon
• bbn31
• actaz
• tnd23
• alt
• r31
• tnd_nom23
• tnd31I
• bb31
• time_offset
• tnd31
• bbn23
• tbskytip31
• liqtip
• vaptip
• actel
• r23
• bb23
• tnd_nom31
• tkbb
• tc31
• tkxc
• tbskytip23
• lat
• tnd23I
• tkair
• tipsky31

• Radiation, longwave, brightness temperature, 23.8 GHz(tbsky23)
• time_offset
• vap_sdev
• liq_sdev
• num_obs_irt
• 31.4 GHz sky brightness temperature(tbsky31)
• lon
• Temperature, brightness, longwave(ir_temp)
• base_time
• tbsky31_sdev
• dlm_flag_periods
• num_obs_ir
• water_flag_periods
• Total water vapor along LOS path(vap)
• tbsky23_sdev
• 31tbsky
• 23tbsky
• alt
• ir_temp_sdev
• num_obs
• Total liquid water along LOS path(liq)
• dlm_flag_fraction
• lat
• water_flag_fraction

• Raw data stream - documentation not supported

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

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.

• liqtip
• tbsky31tip

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

SGP/MWR/B1 - Noisy data

After the instrument was returned to service, the brightness temperature data came up 
extremely noisy.  Disregard brightness temperature data as well as PWV and LWP retrievals 
collected during the indicated time.

• vaptip
• tbskytip31
• liqtip
• tbskytip23

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

SGP/MWR/B4 - Occasional spikes in data

Between 12/7 and 12/29 the 23.8-GHz brightness temperature was affected by the presence of 
spikes due to interference that was more active between 12/7 and 12/15 and then 
diminished. The spikes affect the PWV and the LWP as well.

Spikes happen two or three times a day. Review the data to determine where the spikes 
happen and disregard or filter out the affected points.

• vaptip
• tbskytip23
• liqtip
• tbskytip31

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

SGP/MWR/B1 - Missing data

Data are missing and unrecoverable.

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

SGP/MWR/B6 - Loss of thermal stabilization

Data are erratic due to loss of thermal stabilization of the instrument.

• Radiation, longwave, brightness temperature, 23.8 GHz(tbsky23)
• Total water vapor along LOS path(vap)
• Total liquid water along LOS path(liq)
• 31.4 GHz sky brightness temperature(tbsky31)
• tnd_nom23
• tc23
• tnd23
• sky31
• tc31
• tnd31
• tnd_nom31

• tnd23
• tnd23I
• vaptip
• tbskytip23
• tnd_nom23
• tnd_nom31
• tc23
• tbskytip31
• tnd31
• tc31
• tnd31I
• liqtip

SGP/MWR/B1 - Noisy data

After a software crash data were very noisy.

• vaptip
• tbskytip31
• liqtip
• tipsky23
• tbskytip23
• tipsky31

• Total liquid water along LOS path(liq)
• Radiation, longwave, brightness temperature, 23.8 GHz(tbsky23)
• sky31
• sky23
• Total water vapor along LOS path(vap)
• 31.4 GHz sky brightness temperature(tbsky31)

SGP/MWR/B1 - Increased noise level

The radiometer was experiencing intermittent increase in the noise level of the two 
channels. Although it looks like the radiometer was still able to calibrate, the increased 
noise level may have resulted in a reduced number of tip curves collected. The increased 
noise was intermittent and lasted for a few hours at a time.

• vaptip
• tbskytip31
• liqtip
• tbskytip23

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

SGP/MWR/B6 - Missing data

Data are missing and unrecoverable.

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

• tknd
• tkxc
• bb31
• tc23
• tkair
• tkbb
• bbn23
• alt
• r23
• bb23
• lon
• tipsky31
• r31
• base_time
• bbn31
• tnd23I
• tnd_nom23
• tipsky23
• tbskytip31
• actaz
• tnd31
• wet_window
• lat
• tnd23
• vaptip
• tbskytip23
• tnd_nom31
• time_offset
• tc31
• actel
• tnd31I
• liqtip