DQR ID | Subject | Data Streams Affected |
---|
D000717.1 | TWP/MWR/C1 - Rain on window | twpmwrlosC1.b1, twpmwrtipC1.a1 |
D030312.9 | TWP/MWR/C1 - Intermittent Negative Sky Brightness Temperatures | twpmwrlosC1.b1 |
D040220.1 | TWP/MWR/C1 - wrong azimuth | twpmwrlosC1.b1 |
D050725.9 | TWP/MWR/C1 - Reprocessed: Revised Retrieval Coefficients | twp5mwravgC1.c1, twpmwrlosC1.b1, twpmwrtipC1.a1 |
D050928.1 | TWP/MWR/C1 - New software version (4.15) installed | twpmwrtipC1.a1, twpmwrlosC1.b1 |
D060420.6 | TWP/MWR/C1 - Software Change | twpmwrlosC1.b1 |
D060420.9 | TWP/MWR/C1 - software upgrade (version 3.29) | twpmwrlosC1.b1 |
D061114.2 | TWP/MWR/C1 - Radiometer failure | twpmwrC1.00, twpmwrlosC1.b1, twpmwrtipC1.a1 |
D070105.1 | TWP/MWR/C1 - Missing data | twpmwrlosC1.b1, twpmwrtipC1.a1 |
D070412.3 | TWP/MWR/C1/C2 - Sun in the field of view | twpmwrlosC1.b1, twpmwrlosC2.b1, twpmwrtipC1.a1, twpmwrtipC2.a1 |
D070613.1 | TWP/MWR/C1 - Intermittent data | twpmwrlosC1.b1, twpmwrtipC1.a1 |
D071208.1 | TWP/MWR/C1 - Incorrect ambient temperature readings | twpmwrlosC1.b1, twpmwrtipC1.a1 |
D081013.2 | TWP/MWR/C1 - Short periods of wrong ambient temperature | twpmwrlosC1.b1, twpmwrtipC1.a1 |
D090114.4 | TWP/MWR/C1 - Ambient temperature data missing | twpmwrlosC1.b1, twpmwrtipC1.a1 |
D110221.2 | TWP/MWR/C1 - Intermittent data due to computer problems | twpmwrtipC1.a1, twpmwrlosC1.b1 |
D111214.1 | TWP/MWR/C1 - Rain events not flagged | twpmwrlosC1.b1, twpmwrtipC1.a1 |
Subject: | TWP/MWR/C1 - Rain on window |
DataStreams: | twpmwrlosC1.b1, twpmwrtipC1.a1
|
Description: | The data is subject to contamination due to rain on the sensor window
and should be used with caution because the heater/blower assembly that
prevents water from accumulating on the sensor's teflon window was out
of commission. |
Measurements: | twpmwrtipC1.a1: - r23
- wet_window
- r31
- bbn23
- bb31
- tipsky31
- bb23
- tipsky23
- tipn
- bbn31
- Temperature, brightness, longwave(ir_temp)
twpmwrlosC1.b1: - wet_window
- Total liquid water along LOS path(liq)
- 31.4 GHz sky brightness temperature(tbsky31)
- Temperature, brightness, longwave(ir_temp)
- Radiation, longwave, brightness temperature, 23.8 GHz(tbsky23)
- Total water vapor along LOS path(vap)
|
Subject: | TWP/MWR/C1 - Intermittent Negative Sky Brightness Temperatures |
DataStreams: | twpmwrlosC1.b1
|
Description: | 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 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 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. |
Measurements: | twpmwrlosC1.b1: - 31.4 GHz sky brightness temperature(tbsky31)
- Total liquid water along LOS path(liq)
- Total water vapor along LOS path(vap)
- Radiation, longwave, brightness temperature, 23.8 GHz(tbsky23)
|
Subject: | TWP/MWR/C1 - Reprocessed: Revised Retrieval Coefficients |
DataStreams: | twp5mwravgC1.c1, twpmwrlosC1.b1, twpmwrtipC1.a1
|
Description: | 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).
The Rosenkranz-based retrieval coefficients became active at TWP.C1
20020504.0200. The MONORTM-based retrieval coefficients became active
at TWP.C1 20050630.2100.
Note: The TWP.C1 data for 19961011-20050630 have been reprocessed to apply the |
Measurements: | twp5mwravgC1.c1: - Total liquid water along LOS path(liq)
- Total water vapor along LOS path(vap)
twpmwrtipC1.a1:
twpmwrlosC1.b1: - Total liquid water along LOS path(liq)
- Total water vapor along LOS path(vap)
|
Subject: | TWP/MWR/C1 - New software version (4.15) installed |
DataStreams: | twpmwrtipC1.a1, twpmwrlosC1.b1
|
Description: | A problem began with the installation of MWR.EXE version 4.12 in October 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. |
Measurements: | twpmwrtipC1.a1: - tnd31
- tipsky31
- bbn31
- tbskytip31
- Temperature, brightness, longwave(ir_temp)
- tnd23
- r23
- tnd31I
- tnd_nom23
- tknd
- tbskytip23
- tc23
- tkbb1
- tkbb2
- r31
- liqtip
- bb31
- tkxc
- tc31
- tnd_nom31
- tkbb
- tipn
- vaptip
- tnd23I
- tkair
- bbn23
- bb23
- tipsky23
twpmwrlosC1.b1: - tkair
- IR Brightness Temperature(sky_ir_temp)
- bbn23
- Temperature, brightness, longwave(ir_temp)
- tnd31
- Radiation, longwave, brightness temperature, 23.8 GHz(tbsky23)
- tnd_nom31
- Total liquid water along LOS path(liq)
- tc31
- tknd
- bb31
- tnd_nom23
- sky23
- tkxc
- sky31
- tc23
- tkbb
- bbn31
- bb23
- 31.4 GHz sky brightness temperature(tbsky31)
- tnd23
- Total water vapor along LOS path(vap)
|
Subject: | TWP/MWR/C1 - Software Change |
DataStreams: | twpmwrlosC1.b1
|
Description: | The MWR operating software was changed on 27 February 1999 to provide additional
functionality as described below.
NEW FEATURES
1. Faster sampling rate
Standard line-of-sight (LOS) observations can now be acquired at 15-second intervals vs.
20-second intervals previously. (The standard LOS cycle is comprised of one sky sample per
blackbody sample and gain update.)
2. More flexible sampling strategy
Multiple sky observations can be acquired during a LOS cycle, up to 1024 per gain update.
This permits sky samples to be acquired at intervals of 2.67 seconds for improved
temporal resolution of cloud liquid water variations and better coordination with the millimeter
cloud radar during IOPs.
3. Separation of zenith LOS observations from TIP data
When the radiometer is in TIP mode, the zenith LOS observations are now extracted, the PWV
and LWP computed and reported separately in the output file. This eliminates the periods
of missing LOS data during calibration checks/updates.
4. Automatic self-calibration
The software now permits the calibration to be updated at specified intervals or
continuously. In the first case, LOS mode is automatically changed to TIP mode at user-specified
intervals or whenever clear sky conditions occur, the tip data reduced, the calibration
updated, and the radiometer returned to LOS mode without operator intervention. In the
second case, the radiometer is continuously is TIP mode until changed by the operator.
5. Graphical user display
The graphical display is comprised of a status display, a message display, a temperature
plot, a plot of the retrieved PWV and LWP, and (in TIP mode) a plot of the latest tip
curves. |
Measurements: | twpmwrlosC1.b1: - actel
- tkair
- IR Brightness Temperature(sky_ir_temp)
- lon
- actaz
- bb31
- tnd_nom23
- sky23
- bbn23
- tkxc
- tnd31
- Temperature, brightness, longwave(ir_temp)
- sky31
- tc23
- tkbb
- time_offset
- Radiation, longwave, brightness temperature, 23.8 GHz(tbsky23)
- wet_window
- bbn31
- bb23
- tnd_nom31
- Total liquid water along LOS path(liq)
- 31.4 GHz sky brightness temperature(tbsky31)
- tc31
- tnd23
- lat
- tknd
- base_time
- alt
- Total water vapor along LOS path(vap)
|
Subject: | TWP/MWR/C1 - Radiometer failure |
DataStreams: | twpmwrC1.00, twpmwrlosC1.b1, twpmwrtipC1.a1
|
Description: | The instrument stopped responding and had to be powered off. Suspect cause of failure is a
faulty digital board. |
Measurements: | twpmwrC1.00: - Raw data stream - documentation not supported
twpmwrtipC1.a1: - 31bb
- tnd31
- alt
- 31expave
- tipsky31
- tbskytip31
- bbn31
- 23expave
- Temperature, brightness, longwave(ir_temp)
- 23ndiode
- 31tipsky
- base_time
- airm
- actel
- 23tipskynd
- tnd23
- 31gain
- actaz
- r23
- 31tipbb
- wet_window
- 23bbn
- 23tbzenith
- 31bbn
- 31tipskynd
- tnd31I
- 31r
- tnd_nom23
- 23tipbb
- tknd
- tbskytip23
- tc23
- 23bb
- tkbb1
- tkbb2
- 23gain
- 23tipsky
- r31
- liqtip
- bb31
- tkxc
- tc31
- tnd_nom31
- tkbb
- tipn
- vaptip
- lon
- tnd23I
- time_offset
- tkair
- bbn23
- 31ndiode
- lat
- bb23
- tipsky23
- 31tbzenith
- 23r
twpmwrlosC1.b1: - tkair
- IR Brightness Temperature(sky_ir_temp)
- lon
- actaz
- bbn23
- Temperature, brightness, longwave(ir_temp)
- tnd31
- Radiation, longwave, brightness temperature, 23.8 GHz(tbsky23)
- wet_window
- tnd_nom31
- Total liquid water along LOS path(liq)
- tc31
- lat
- tknd
- alt
- actel
- bb31
- tnd_nom23
- sky23
- tkxc
- sky31
- tc23
- tkbb
- time_offset
- bbn31
- bb23
- 31.4 GHz sky brightness temperature(tbsky31)
- tnd23
- base_time
- Total water vapor along LOS path(vap)
|
Subject: | TWP/MWR/C1/C2 - Sun in the field of view |
DataStreams: | twpmwrlosC1.b1, twpmwrlosC2.b1, twpmwrtipC1.a1, twpmwrtipC2.a1
|
Description: | Every day between around noon local time (usually between 1 and 2 AM UTC time) there is an
increase in the brightness temperatures due to the sun in the field of view of the
radiometer.
The effect lasts less than an hour around local noon (usually between 1 and 2 AM UTC
time). The effect appears as a smooth increase and decrease in brightness temperature. |
Measurements: | twpmwrtipC2.a1:
twpmwrtipC1.a1: - vaptip
- liqtip
- tbskytip23
- tbskytip31
twpmwrlosC1.b1: - Total liquid water along LOS path(liq)
- sky23
- 31.4 GHz sky brightness temperature(tbsky31)
- sky31
- Radiation, longwave, brightness temperature, 23.8 GHz(tbsky23)
- Total water vapor along LOS path(vap)
twpmwrlosC2.b1: - sky31
- 31.4 GHz sky brightness temperature(tbsky31)
- sky23
- Total liquid water along LOS path(liq)
- Total water vapor along LOS path(vap)
- Radiation, longwave, brightness temperature, 23.8 GHz(tbsky23)
|
Subject: | TWP/MWR/C1 - Intermittent data |
DataStreams: | twpmwrlosC1.b1, twpmwrtipC1.a1
|
Description: | After a computer change the MWR program did not restart properly. Data are intermittent
between 6/12 and 6/17. |
Measurements: | twpmwrtipC1.a1: - 31bb
- tnd31
- alt
- 31expave
- tipsky31
- tbskytip31
- bbn31
- 23expave
- Temperature, brightness, longwave(ir_temp)
- 23ndiode
- 31tipsky
- base_time
- airm
- actel
- 23tipskynd
- tnd23
- 31gain
- actaz
- r23
- 31tipbb
- wet_window
- 23bbn
- 23tbzenith
- 31bbn
- 31tipskynd
- tnd31I
- 31r
- tnd_nom23
- 23tipbb
- tknd
- tbskytip23
- tc23
- 23bb
- tkbb1
- tkbb2
- 23gain
- 23tipsky
- r31
- liqtip
- bb31
- tkxc
- tc31
- tnd_nom31
- tkbb
- tipn
- vaptip
- lon
- tnd23I
- time_offset
- tkair
- bbn23
- 31ndiode
- lat
- bb23
- tipsky23
- 31tbzenith
- 23r
twpmwrlosC1.b1: - tkair
- IR Brightness Temperature(sky_ir_temp)
- lon
- actaz
- bbn23
- Temperature, brightness, longwave(ir_temp)
- tnd31
- Radiation, longwave, brightness temperature, 23.8 GHz(tbsky23)
- wet_window
- tnd_nom31
- Total liquid water along LOS path(liq)
- tc31
- lat
- tknd
- alt
- actel
- bb31
- tnd_nom23
- sky23
- tkxc
- sky31
- tc23
- tkbb
- time_offset
- bbn31
- bb23
- 31.4 GHz sky brightness temperature(tbsky31)
- tnd23
- base_time
- Total water vapor along LOS path(vap)
|
Subject: | TWP/MWR/C1 - Intermittent data due to computer problems |
DataStreams: | twpmwrtipC1.a1, twpmwrlosC1.b1
|
Description: | Between 1/7 and 1/9 there are large segments of data missing because of a computer
problem. |
Measurements: | twpmwrtipC1.a1: - 31bb
- tnd31
- alt
- 31expave
- tipsky31
- bbn31
- 23expave
- tbskytip31
- Temperature, brightness, longwave(ir_temp)
- 23ndiode
- 31tipsky
- base_time
- airm
- actel
- 23tipskynd
- tnd23
- 31gain
- actaz
- r23
- 31tipbb
- 31bbn
- 23tbzenith
- 23bbn
- wet_window
- 31tipskynd
- tnd31I
- 31r
- tnd_nom23
- 23tipbb
- tknd
- tbskytip23
- tc23
- 23bb
- tkbb1
- tkbb2
- 23tipsky
- 23gain
- r31
- liqtip
- bb31
- tkxc
- tc31
- tnd_nom31
- tkbb
- tipn
- lon
- vaptip
- tnd23I
- time_offset
- tkair
- bbn23
- 31ndiode
- lat
- bb23
- tipsky23
- 31tbzenith
- 23r
twpmwrlosC1.b1: - tkair
- IR Brightness Temperature(sky_ir_temp)
- lon
- actaz
- bbn23
- tnd31
- Temperature, brightness, longwave(ir_temp)
- Radiation, longwave, brightness temperature, 23.8 GHz(tbsky23)
- wet_window
- tnd_nom31
- Total liquid water along LOS path(liq)
- tc31
- lat
- tknd
- alt
- actel
- bb31
- tnd_nom23
- sky23
- tkxc
- sky31
- tc23
- tkbb
- time_offset
- bbn31
- bb23
- 31.4 GHz sky brightness temperature(tbsky31)
- tnd23
- base_time
- Total water vapor along LOS path(vap)
|