DQR ID | Subject | Data Streams Affected |
---|
D010201.1 | NSA/MWR/C1 - Temperature Stabilization of Noise Diode Impaired | nsamwrlosC1.a1, nsa5mwravgC1.c1, nsamwrlosC1.b1 |
D010202.2 | NSA/MWR/C1 - negative sky brightness temperatures | nsamwrlosC1.a1, nsamwrlosC1.b1 |
D010202.3 | NSA/MWR/C1 - negative sky brightness temperatures | nsamwrlosC1.a1, nsamwrlosC1.b1 |
D010202.5 | NSA/MWR/C1 - Reprocess: calibration change | nsamwrlosC1.a1, nsamwrlosC1.b1 |
D010202.6 | NSA/MWR/C1 - incorrect flagging of data | nsamwrlosC1.b1, nsamwrlosC1.a1, nsamwrtipC1.a1 |
D010202.7 | NSA/MWR/C1 - incorrect flagging of data | nsamwrlosC1.b1, nsamwrlosC1.a1, nsamwrtipC1.a1 |
D010504.4 | NSA/MWR/C1 - Reprocess: calibration change | nsamwrlosC1.a1, nsamwrlosC1.b1, nsamwrtipC1.a1 |
D020122.1 | NSA/MWR/C1 - Reprocess: wrong calibration | nsamwrlosC1.a1, nsamwrlosC1.b1 |
D020823.36 | NSA/MWR/C1 - Data spikes, possibly due to cleaning events | nsamwrlosC1.a1, nsamwrlosC1.b1 |
D021017.1 | NSA/MWR/C1 - MWR digital board failure | nsamwrlosC1.a1, nsamwrlosC1.b1 |
D030312.6 | SGP/MWR/C1 - Intermittent Negative Sky Brightness Temperatures | nsamwrlosC1.a1, nsamwrlosC1.b1 |
D030515.3 | NSA/MWR/C1 - no air temperature signal | nsamwrC1.00, nsamwrlosC1.b1, nsamwrtipC1.a1 |
D030822.7 | NSA/MWR/C1 - min/max/delta values incorrect | nsamwrlosC1.b1 |
D050725.7 | NSA/MWR/C1 - Reprocess: Revised Calibration Coefficients | nsa5mwravgC1.c1, nsamwrlosC1.a1, nsamwrlosC1.b1, nsamwrtipC1.a1, nsaqmemwrcolC1.c1 |
D050928.3 | NSA/MWR/C1 - New software version (4.15) installed | nsamwrlosC1.b1, nsamwrtipC1.a1 |
D101025.1 | NSA/MWR/C1 - Missing data | nsamwrtipC1.a1, nsamwrlosC1.b1 |
Subject: | NSA/MWR/C1 - Temperature Stabilization of Noise Diode Impaired |
DataStreams: | nsamwrlosC1.a1, nsa5mwravgC1.c1, nsamwrlosC1.b1
|
Description: | 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. |
Measurements: | nsa5mwravgC1.c1: - tbsky31_sdev
- tbsky23_sdev
- Total liquid water along LOS path(liq)
- ir_temp_sdev
- num_obs_irt
- liq_sdev
- num_obs
- Radiation, longwave, brightness temperature, 23.8 GHz(tbsky23)
- Temperature, brightness, longwave(ir_temp)
- Total water vapor along LOS path(vap)
- water_flag_fraction
- vap_sdev
- 31.4 GHz sky brightness temperature(tbsky31)
nsamwrlosC1.a1: - bb31
- tnd_nom23
- 31.4 GHz sky brightness temperature(tbsky31)
- tnd23
- Total liquid water along LOS path(liq)
- Total water vapor along LOS path(vap)
- bbn31
- tkair
- tkxc
- sky23
- bb23
- tkbb
- sky31
- tnd31
- tc23
- tnd_nom31
- Temperature, brightness, longwave(ir_temp)
- Radiation, longwave, brightness temperature, 23.8 GHz(tbsky23)
- tc31
- bbn23
- tknd
- wet_window
nsamwrlosC1.b1: - 31.4 GHz sky brightness temperature(tbsky31)
- Total water vapor along LOS path(vap)
- wet_window
- Total liquid water along LOS path(liq)
- Radiation, longwave, brightness temperature, 23.8 GHz(tbsky23)
- Temperature, brightness, longwave(ir_temp)
|
Subject: | NSA/MWR/C1 - negative sky brightness temperatures |
DataStreams: | nsamwrlosC1.a1, nsamwrlosC1.b1
|
Description: | 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. |
Measurements: | nsamwrlosC1.a1: - 31.4 GHz sky brightness temperature(tbsky31)
- Total liquid water along LOS path(liq)
- tkxc
- Total water vapor along LOS path(vap)
- Radiation, longwave, brightness temperature, 23.8 GHz(tbsky23)
nsamwrlosC1.b1: - 31.4 GHz sky brightness temperature(tbsky31)
- Total water vapor along LOS path(vap)
- Total liquid water along LOS path(liq)
- Radiation, longwave, brightness temperature, 23.8 GHz(tbsky23)
|
Subject: | NSA/MWR/C1 - negative sky brightness temperatures |
DataStreams: | nsamwrlosC1.a1, nsamwrlosC1.b1
|
Description: | The data exhibit occasional negative sky brightness temperatures.
The problem was corrected when the computer was reconfigured following a virus infection. |
Measurements: | nsamwrlosC1.a1: - 31.4 GHz sky brightness temperature(tbsky31)
- Total liquid water along LOS path(liq)
- tkxc
- Total water vapor along LOS path(vap)
- Radiation, longwave, brightness temperature, 23.8 GHz(tbsky23)
nsamwrlosC1.b1: - 31.4 GHz sky brightness temperature(tbsky31)
- Total water vapor along LOS path(vap)
- Total liquid water along LOS path(liq)
- Radiation, longwave, brightness temperature, 23.8 GHz(tbsky23)
|
Subject: | NSA/MWR/C1 - Reprocess: calibration change |
DataStreams: | nsamwrlosC1.a1, nsamwrlosC1.b1
|
Description: | 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. |
Measurements: | nsamwrlosC1.a1: - 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)
nsamwrlosC1.b1: - 31.4 GHz sky brightness temperature(tbsky31)
- Total water vapor along LOS path(vap)
- Total liquid water along LOS path(liq)
- Radiation, longwave, brightness temperature, 23.8 GHz(tbsky23)
|
Subject: | NSA/MWR/C1 - Reprocess: calibration change |
DataStreams: | nsamwrlosC1.a1, nsamwrlosC1.b1, nsamwrtipC1.a1
|
Description: | The computer was replaced but not configured correctly for the MWR. |
Measurements: | nsamwrlosC1.a1: - tnd_nom23
- 31.4 GHz sky brightness temperature(tbsky31)
- tc23
- tnd_nom31
- Total liquid water along LOS path(liq)
- Total water vapor along LOS path(vap)
- Radiation, longwave, brightness temperature, 23.8 GHz(tbsky23)
- tc31
nsamwrlosC1.b1: - 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)
nsamwrtipC1.a1: - tnd_nom31
- tnd_nom23
- tipsky31
- tc31
- tc23
- tipsky23
|
Subject: | NSA/MWR/C1 - Reprocess: wrong calibration |
DataStreams: | nsamwrlosC1.a1, nsamwrlosC1.b1
|
Description: | 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. |
Measurements: | nsamwrlosC1.a1: - 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)
nsamwrlosC1.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: | NSA/MWR/C1 - Data spikes, possibly due to cleaning events |
DataStreams: | nsamwrlosC1.a1, nsamwrlosC1.b1
|
Description: | 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. |
Measurements: | nsamwrlosC1.a1: - 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)
nsamwrlosC1.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: | NSA/MWR/C1 - MWR digital board failure |
DataStreams: | nsamwrlosC1.a1, nsamwrlosC1.b1
|
Description: | 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. |
Measurements: | nsamwrlosC1.a1: - 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)
nsamwrlosC1.b1: - 31.4 GHz sky brightness temperature(tbsky31)
- Total water vapor along LOS path(vap)
- Total liquid water along LOS path(liq)
- Radiation, longwave, brightness temperature, 23.8 GHz(tbsky23)
|
Subject: | SGP/MWR/C1 - Intermittent Negative Sky Brightness Temperatures |
DataStreams: | nsamwrlosC1.a1, nsamwrlosC1.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 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: | nsamwrlosC1.a1: - 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)
nsamwrlosC1.b1: - 31.4 GHz sky brightness temperature(tbsky31)
- Total water vapor along LOS path(vap)
- Total liquid water along LOS path(liq)
- Radiation, longwave, brightness temperature, 23.8 GHz(tbsky23)
|
Subject: | NSA/MWR/C1 - Reprocess: Revised Calibration Coefficients |
DataStreams: | nsa5mwravgC1.c1, nsamwrlosC1.a1, nsamwrlosC1.b1, nsamwrtipC1.a1, nsaqmemwrcolC1.c1
|
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).
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. |
Measurements: | nsa5mwravgC1.c1: - Total water vapor along LOS path(vap)
- Total liquid water along LOS path(liq)
nsamwrlosC1.a1: - Total liquid water along LOS path(liq)
- Total water vapor along LOS path(vap)
nsamwrlosC1.b1: - Total water vapor along LOS path(vap)
- Total liquid water along LOS path(liq)
nsaqmemwrcolC1.c1:
nsamwrtipC1.a1:
|
Subject: | NSA/MWR/C1 - New software version (4.15) installed |
DataStreams: | nsamwrlosC1.b1, nsamwrtipC1.a1
|
Description: | 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. |
Measurements: | nsamwrlosC1.b1: - 31.4 GHz sky brightness temperature(tbsky31)
- tnd23
- tknd
- tnd_nom23
- bb31
- IR Brightness Temperature(sky_ir_temp)
- sky23
- tkxc
- Total water vapor along LOS path(vap)
- tkbb
- bbn23
- tkair
- Total liquid water along LOS path(liq)
- Radiation, longwave, brightness temperature, 23.8 GHz(tbsky23)
- tnd31
- bb23
- tc23
- sky31
- tnd_nom31
- tc31
- Temperature, brightness, longwave(ir_temp)
- bbn31
nsamwrtipC1.a1: - tnd23
- tkxc
- tnd_nom23
- bb31
- tc31
- tnd31I
- tkbb
- liqtip
- bbn31
- tbskytip31
- r31
- tkair
- vaptip
- bb23
- tnd_nom31
- tnd23I
- tknd
- tipsky31
- tc23
- tipsky23
- r23
- tbskytip23
- bbn23
- tnd31
|