| DQR ID | Subject | Data Streams Affected |
|---|---|---|
| D000121.1 | SGP/MWR/B5 - wrong calibration | sgp5mwravgB5.c1, sgpmwrlosB5.00, sgpmwrlosB5.a1, sgpmwrlosB5.b1, sgpmwrtipB5.a1 |
| D001110.4 | SGP/MWR/B4 - Sky Temperatures Noisy | sgpmwrlosB4.a1, sgpmwrlosB4.b1, sgpmwrtipB4.a0 |
| D001114.16 | SGP/MWR/B4 - Sky Temperatures Noisy | sgpmwrlosB4.a1, sgpmwrlosB4.b1, sgpmwrtipB4.a1 |
| D001115.1 | SGP/MWR/B1 - occasional negative brightness temperatures | sgpmwrlosB1.00, sgpmwrlosB1.a1, sgpmwrlosB1.b1, sgpmwrtipB1.00, sgpmwrtipB1.a1 |
| D010111.26 | SGP/MWR/B1 - Spikes in sky temperature data | sgpmwrlosB1.a1, sgpmwrlosB1.b1 |
| D010111.29 | SGP/MWR/B4 - Negtive spikes in sky temperature data | sgpmwrlosB4.a1, sgpmwrlosB4.b1 |
| D010208.2 | SGP/MWR/B4 - noisy data | sgpmwrlosB4.a1, sgpmwrlosB4.b1, sgpmwrtipB4.a1 |
| D010208.4 | SGP/MWR/B1 - noisy data | sgpmwrlosB1.a1, sgpmwrlosB1.b1, sgpmwrtipB1.a1 |
| D010426.1 | SGP/MWR/B4 - spare MWR | sgpmwrlosB4.a0, sgpmwrlosB4.a1, sgpmwrlosB4.b1, sgpmwrtipB4.a0, sgpmwrtipB4.a1 |
| D030214.1 | SGP/MWR/B4/C1 - LOS cycle skipping | sgpmwrlosB4.a1, sgpmwrlosB4.b1, sgpmwrlosC1.a1, sgpmwrlosC1.b1 |
| D030312.2 | SGP/MWR/B1 - Intermittent Negative Sky Brightness Temperatures | sgpmwrlosB1.a1, sgpmwrlosB1.b1 |
| D030312.3 | SGP/MWR/B4 - Intermittent Negative Sky Brightness Temperatures | sgpmwrlosB4.a1, sgpmwrlosB4.b1 |
| D030312.4 | SGP/MWR/B5 - Intermittent Negative Sky Brightness Temperatures | sgpmwrlosB5.a1, sgpmwrlosB5.b1 |
| D030822.2 | SGP/MWR/B1 - min/max/delta values incorrect | sgpmwrlosB1.b1 |
| D030822.3 | SGP/MWR/B4 - min/max/delta values incorrect | sgpmwrlosB4.b1 |
| D030822.4 | SGP/MWR/B5 - min/max/delta values incorrect | sgpmwrlosB5.b1 |
| D030909.1 | SGP/MWR/B1 - thermal instability | sgpmwrlosB1.a1, sgpmwrlosB1.b1 |
| D031106.2 | SGP/MWR/B4 - no air temperature signal | sgpmwrlosB4.b1, sgpmwrtipB4.a1 |
| D040322.2 | SGP/MWR/B5 - thermal instability | sgpmwrlosB5.a1, sgpmwrtipB5.a1 |
| D040819.1 | SGP/MWR/B1/B4/B5 - Data dropouts due to serial comm problems | sgpmwrlosB1.a1, sgpmwrlosB4.a1, sgpmwrlosB5.a1 |
| D040819.3 | SGP/MWR/B1 - Loss of thermal stabilization | sgp5mwravgB1.c1, sgpmwrlosB1.a0, sgpmwrlosB1.a1 |
| D040819.5 | SGP/MWR/B5 - Loss of thermal stabilization | sgp5mwravgB5.c1, sgpmwrlosB5.a0, sgpmwrlosB5.a1 |
| D041021.3 | SGP/MWR/B4 - Heater problem | sgpmwrlosB4.b1, sgpmwrtipB4.a1 |
| D050725.2 | SGP/MWR/B1 - Reprocess: Revised Retrieval Coefficients | sgp5mwravgB1.c1, sgpmwrlosB1.a1, sgpmwrlosB1.b1, sgpmwrtipB1.a1, sgpqmemwrcolB1.c1 |
| D050725.3 | SGP/MWR/B4 - Reprocess: Revised Retrieval Coefficients | sgp5mwravgB4.c1, sgpmwrlosB4.a1, sgpmwrlosB4.b1, sgpmwrtipB4.a1, sgpqmemwrcolB4.c1 |
| D050725.4 | SGP/MWR/B5 - Reprocess: Revised Retrieval Coefficients | sgp5mwravgB5.c1, sgpmwrlosB5.a1, sgpmwrlosB5.b1, sgpmwrtipB5.a1, sgpqmemwrcolB5.c1 |
| D050822.5 | SGP/MWR/B1 - thermal instability | sgpmwrlosB1.b1, sgpmwrtipB1.a1 |
| D050822.6 | SGP/MWR/B1 - Reprocess: mixer temp adjustment | sgpmwrlosB1.b1, sgpmwrtipB1.a1 |
| D050927.2 | SGP/MWR/B1 - New software version (4.15) installed | sgpmwrlosB1.b1, sgpmwrtipB1.a1 |
| D050927.3 | SGP/MWR/B4 - New software version (4.15) installed | sgpmwrlosB4.b1, sgpmwrtipB4.a1 |
| D050927.4 | SGP/MWR/B5 - New software version (4.15) installed | sgpmwrlosB5.b1, sgpmwrtipB5.a1 |
| D060420.1 | SGP/MWR/B4 - Reprocess: wrong retrievals | sgpmwrlosB4.a1, sgpmwrlosB4.b1, sgpmwrtipB4.a1, sgpqmemwrcolB4.c1 |
| D060420.3 | SGP/MWR/B5 - Reprocess: wrong retrievals | sgpmwrlosB5.a1, sgpmwrlosB5.b1, sgpmwrtipB5.a1, sgpqmemwrcolB5.c1 |
| D060718.3 | SGP/MWR/B5 - Mixer temp unstable | sgpmwrlosB5.b1, sgpmwrtipB5.a1 |
| D060726.1 | SGP/MWR/B1 - Reprocessed: Corrected calibration | sgpmwrB1.00, sgpmwrlosB1.b1, sgpmwrtipB1.a1 |
| D070801.1 | SGP/MWR/B1 - 23.8-GHz brightness temperature slightly high | sgp5mwravgB1.c1, sgpmwrlosB1.b1, sgpmwrtipB1.a1 |
| D071011.4 | SGP/MWR/B5 - Intermittent missing data | sgpmwrlosB5.b1, sgpmwrtipB5.a1 |
| D071129.1 | SGP/MWR/B1 - Calibration failure | sgpmwrlosB1.b1, sgpmwrtipB1.a1 |
| D080410.3 | SGP/MWR/B5 - Some rain events flagged | sgpmwrlosB5.b1, sgpmwrtipB5.a1 |
| D080701.2 | SGP/MWR/B4 - Missing data | sgpmwrlosB4.b1, sgpmwrtipB4.a1 |
| D080724.1 | SGP/MWR/B5 - Missing data | sgpmwrlosB5.b1 |
| D090114.7 | SGP/MWR/B1 - Noisy data | sgpmwrlosB1.b1, sgpmwrtipB1.a1 |
| D090115.2 | SGP/MWR/B4 - Occasional spikes in data | sgpmwrlosB4.b1, sgpmwrtipB4.a1 |
| D090202.4 | SGP/MWR/B1 - Missing data | sgpmwrlosB1.b1 |
| D090225.7 | SGP/MWR/B1 - Noisy data | sgpmwrlosB1.b1, sgpmwrtipB1.a1 |
| D090512.5 | SGP/MWR/B1 - Increased noise level | sgpmwrlosB1.b1, sgpmwrtipB1.a1 |
| D950110.1 | Reprocess: Effect of BBSS ground check on MWR tuning functions | DsgpmwrlosB1.a0, DsgpmwrlosB1.a1, sgpmwrlosB1.a1 |
| D960115.1 | Precipitable Water Vapor (PWV) values at Hillsboro | sgp5mwravgB1.c1, sgpmwrlosB1.a0, sgpmwrlosB1.a1 |
| D960129.2 | SGP/MWR/B1/B5 - Calibration questionable | sgpmwrlosB1.a0, sgpmwrlosB1.a1, sgpmwrlosB5.a0, sgpmwrlosB5.a1 |
| D960207.1 | MWR serial communications problems at Vici | sgpmwrlosB4.a0, sgpmwrlosB4.a1 |
| D960226.3 | calibration checked, noisy 31 GHz channel | sgpmwrlosB4.a0, sgpmwrlosB4.a1 |
| D960404.1 | SGP/MWR/B1/B4/B5 - Reprocess: Error in MWR calibration | sgpmwrlosB1.a0, sgpmwrlosB1.a1, sgpmwrlosB4.a0, sgpmwrlosB4.a1, sgpmwrlosB5.a0, sgpmwrlosB5.a1 |
| D960404.2 | SGP/MWR/B1/B4/B5 - Reprocess: MWR Tuning Functions | sgpmwrlosB1.a0, sgpmwrlosB1.a1, sgpmwrlosB4.a0, sgpmwrlosB4.a1, sgpmwrlosB5.a0, sgpmwrlosB5.a1 |
| D961117.2 | Loss of thermal stabilization | sgpmwrlosB1.a1 |
| D961117.4 | Loss of thermal stabilization | sgpmwrlosB4.a1 |
| D961117.6 | Loss of thermal stabilization | sgpmwrlosB5.a1 |
| D961120.1 | SGP/MWR/B1/B4/B5/B6/C1 - Thermal Stabilization Adjustment | sgp1mwravgC1.c1, sgp5mwravgB1.c1, sgp5mwravgB4.c1, sgp5mwravgB5.c1, sgp5mwravgB6.c1, sgp5mwravgC1.c1, sgpmwrlosB1.a0, sgpmwrlosB1.a1, sgpmwrlosB4.a0, sgpmwrlosB4.a1, sgpmwrlosB5.a0, sgpmwrlosB5.a1, sgpmwrlosB6.a0, sgpmwrlosB6.a1, sgpmwrlosC1.a1, sgpmwrlosC1.b1 |
| D970102.1 | Reprocess: Incorrect calibration installed | sgpmwrlosB4.a0, sgpmwrlosB4.a1, sgpmwrtipB4.a0 |
| D980205.2 | Manually corrected error in header files | sgpmwrlosB1.a0, sgpmwrlosB1.a1, sgpmwrlosB5.a0, sgpmwrlosB5.a1, sgpmwrtipB5.a0 |
| D980209.3 | SGP/MWR/B5 - Reprocess: Calibration update | sgpmwrlosB5.a0, sgpmwrlosB5.a1, sgpmwrtipB5.a0 |
| D980211.1 | SGP/MWR/B5 - Incorrect serial number | sgpmwrlosB5.a0, sgpmwrlosB5.a1, sgpmwrtipB5.a0 |
| D990106.1 | SGP/MWR/B1/B4/B6/C1 - software change | sgpmwrlosB1.a0, sgpmwrlosB1.a1, sgpmwrlosB4.a0, sgpmwrlosB4.a1, sgpmwrlosB6.a0, sgpmwrlosB6.a1, sgpmwrlosC1.a1, sgpmwrlosC1.b1, sgpmwrtipB1.a0, sgpmwrtipB4.a0, sgpmwrtipB6.a0 |
| D990106.2 | SGP/MWR/B5 - Software Change | sgpmwrlosB5.a1 |
| D990108.1 | SGP/MWR/B1 out of calibration | sgpmwrlosB1.a0, sgpmwrlosB1.a1 |
| D990113.1 | SGP/MWR/B1/B4/B5/B6/C1 - software upgrade (version 3.27) | sgpmwrlosB1.a1, sgpmwrlosB4.a1, sgpmwrlosB5.a1, sgpmwrlosB6.a1, sgpmwrlosC1.a1, sgpmwrlosC1.b1, sgpmwrtipB1.a0, sgpmwrtipB4.a0, sgpmwrtipB5.a0, sgpmwrtipB6.a0 |
| D990127.16 | SGP/MWR/B1/B4/B6 - Reprocess: Data Ingest Problem | sgpmwrlosB1.a0, sgpmwrlosB1.a1, sgpmwrlosB4.a0, sgpmwrlosB4.a1, sgpmwrlosB6.a0, sgpmwrlosB6.a1 |
| D990916.1 | SGP/MWR/B1/B4/B5/B6 - data file split at 23:59 | sgpmwrlosB1.a1, sgpmwrlosB1.b1, sgpmwrlosB4.a1, sgpmwrlosB4.b1, sgpmwrlosB5.a1, sgpmwrlosB5.b1, sgpmwrlosB6.a1, sgpmwrlosB6.b1, sgpmwrtipB1.a1, sgpmwrtipB4.a1, sgpmwrtipB5.a1, sgpmwrtipB6.a1 |
| D991102.1 | SGP/MWR/B4 - power lines in field of view | sgp5mwravgB4.c1, sgpmwrlosB4.00, sgpmwrlosB4.a1, sgpmwrlosB4.b1, sgpmwrtipB4.00, sgpmwrtipB4.a1 |
| Start Date | Start Time | End Date | End Time |
|---|---|---|---|
| 10/27/1999 | 1716 | 11/15/1999 | 1500 |
| Subject: | SGP/MWR/B5 - wrong calibration |
| DataStreams: | sgp5mwravgB5.c1, sgpmwrlosB5.00, sgpmwrlosB5.a1, sgpmwrlosB5.b1, sgpmwrtipB5.a1 |
| Description: | An upgrade of the instrument by the manufacturer significantly changed its calibration and the configuration file was not updated with the new calibration values when the instrument was returned to service. |
| Measurements: | sgpmwrlosB5.00:
sgpmwrlosB5.a1:
sgpmwrtipB5.a1:
sgp5mwravgB5.c1:
sgpmwrlosB5.b1:
|
| Start Date | Start Time | End Date | End Time |
|---|---|---|---|
| 06/07/2000 | 0000 | 08/09/2000 | 2359 |
| Subject: | SGP/MWR/B4 - Sky Temperatures Noisy |
| DataStreams: | sgpmwrlosB4.a1, sgpmwrlosB4.b1, sgpmwrtipB4.a0 |
| Description: | The sky temperature data are very noisy, per Victor Morris. |
| Measurements: | sgpmwrlosB4.b1:
sgpmwrtipB4.a0:
sgpmwrlosB4.a1:
|
| Start Date | Start Time | End Date | End Time |
|---|---|---|---|
| 09/20/2000 | 0000 | 09/30/2000 | 2359 |
| Subject: | SGP/MWR/B4 - Sky Temperatures Noisy |
| DataStreams: | sgpmwrlosB4.a1, sgpmwrlosB4.b1, sgpmwrtipB4.a1 |
| Description: | The sky temperature data are very noisy, per Victor Morris. |
| Measurements: | sgpmwrlosB4.b1:
sgpmwrtipB4.a1:
sgpmwrlosB4.a1:
|
| Start Date | Start Time | End Date | End Time |
|---|---|---|---|
| 02/27/2000 | 0000 | 06/07/2000 | 2359 |
| Subject: | SGP/MWR/B1 - occasional negative brightness temperatures |
| DataStreams: | sgpmwrlosB1.00, sgpmwrlosB1.a1, sgpmwrlosB1.b1, sgpmwrtipB1.00, sgpmwrtipB1.a1 |
| Description: | Occasional spikes in the MWR data were observed. Inspection of the data indicates that these are due to spikes in the gain that result from either unrealistically low values of the blackbody target temperature (~150 K) or unrealistically low values of the microwave signal counts when viewing the blackbody target. Unrealistically low values of the mixer temperature have also been observed. |
| Measurements: | sgpmwrlosB1.00:
sgpmwrlosB1.a1:
sgpmwrlosB1.b1:
sgpmwrtipB1.00:
sgpmwrtipB1.a1:
|
| Start Date | Start Time | End Date | End Time |
|---|---|---|---|
| 12/01/2000 | 0000 | 12/31/2000 | 2359 |
| Subject: | SGP/MWR/B1 - Spikes in sky temperature data |
| DataStreams: | sgpmwrlosB1.a1, sgpmwrlosB1.b1 |
| Description: | There are negative spikes in the sky temperature data, per Victor Morris. |
| Measurements: | sgpmwrlosB1.a1:
sgpmwrlosB1.b1:
|
| Start Date | Start Time | End Date | End Time |
|---|---|---|---|
| 12/01/2000 | 0000 | 12/31/2000 | 2359 |
| Subject: | SGP/MWR/B4 - Negtive spikes in sky temperature data |
| DataStreams: | sgpmwrlosB4.a1, sgpmwrlosB4.b1 |
| Description: | There are negative spikes in the sky temperature data, per Victor Morris. |
| Measurements: | sgpmwrlosB4.b1:
sgpmwrlosB4.a1:
|
| Start Date | Start Time | End Date | End Time |
|---|---|---|---|
| 04/05/2000 | 1800 | 01/25/2001 | 2016 |
| Subject: | SGP/MWR/B4 - noisy data |
| DataStreams: | sgpmwrlosB4.a1, sgpmwrlosB4.b1, sgpmwrtipB4.a1 |
| Description: | The MWR exhibited occasional negative sky brightness temperatures that were resolved, after eliminating the instrument and communication lines as the source of the problem, by reformatting and reconfiguring the laptop computer. |
| Measurements: | sgpmwrlosB4.b1:
sgpmwrtipB4.a1:
sgpmwrlosB4.a1:
|
| Start Date | Start Time | End Date | End Time |
|---|---|---|---|
| 11/24/2000 | 0000 | 01/30/2001 | 2050 |
| Subject: | SGP/MWR/B1 - noisy data |
| DataStreams: | sgpmwrlosB1.a1, sgpmwrlosB1.b1, sgpmwrtipB1.a1 |
| Description: | The MWR exhibited occasional negative sky brightness temperatures that were resolved, after eliminating the instrument and communication lines as the source of the problem, by reformatting and reconfiguring the laptop computer. |
| Measurements: | sgpmwrlosB1.a1:
sgpmwrtipB1.a1:
sgpmwrlosB1.b1:
|
| Start Date | Start Time | End Date | End Time |
|---|---|---|---|
| 01/09/2001 | 1800 | 01/23/2001 | 1755 |
| Subject: | SGP/MWR/B4 - spare MWR |
| DataStreams: | sgpmwrlosB4.a0, sgpmwrlosB4.a1, sgpmwrlosB4.b1, sgpmwrtipB4.a0, sgpmwrtipB4.a1 |
| Description: | A spare MWR (s.n.38) was temporarily installed at Vici to help resolve problems with the occurance of negative sky brightness temperatures (see BCR-310 and P000712.1). |
| Measurements: | sgpmwrlosB4.b1:
sgpmwrlosB4.a0:
sgpmwrtipB4.a1:
sgpmwrtipB4.a0:
sgpmwrlosB4.a1:
|
| Start Date | Start Time | End Date | End Time |
|---|---|---|---|
| 07/31/2002 | 2034 | 11/05/2002 | 1815 |
| Subject: | SGP/MWR/B4/C1 - LOS cycle skipping |
| DataStreams: | sgpmwrlosB4.a1, sgpmwrlosB4.b1, sgpmwrlosC1.a1, sgpmwrlosC1.b1 |
| Description: | 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. |
| Measurements: | sgpmwrlosB4.b1:
sgpmwrlosC1.b1:
sgpmwrlosC1.a1:
sgpmwrlosB4.a1:
|
| Start Date | Start Time | End Date | End Time |
|---|---|---|---|
| 02/28/2000 | 0300 | 07/16/2002 | 2200 |
| Subject: | SGP/MWR/B1 - Intermittent Negative Sky Brightness Temperatures |
| DataStreams: | sgpmwrlosB1.a1, sgpmwrlosB1.b1 |
| Description: | Several related and recurring problems with the SGP MWRs have been reported dating back to 1999. These problems were due to the occurrence of blackbody signals (in counts) that were half of those expected. The symptoms included noisy data (especially at Purcell), spikes in the data (especially at Vici), negative brightness temperatures, and apparent loss of serial communication between the computer and the radiometer, which results in a self-termination of the MWR program (especially at the CF). Because these all initially appeared to be hardware-related problems, the instrument mentor and SGP site operations personnel (1) repeatedly cleaned and replaced the fiber optic comm. components, (2) swapped radiometers, (3) sent radiometers back to Radiometrics for evaluation (which has not revealed any instrument problems), and (4) reconfigured the computer's operating system. Despite several attempts to isolate and correct it, the problem persisted. It became apparent that some component of the Windows98 configuration conflicted with the DOS-based MWR program or affected the serial port or the contents of the serial port buffer. This problem was finally corrected by upgrading the MWR software with a new Windows-compatible program. |
| Measurements: | sgpmwrlosB1.a1:
sgpmwrlosB1.b1:
|
| Start Date | Start Time | End Date | End Time |
|---|---|---|---|
| 02/01/2000 | 2100 | 07/09/2002 | 1700 |
| Subject: | SGP/MWR/B4 - Intermittent Negative Sky Brightness Temperatures |
| DataStreams: | sgpmwrlosB4.a1, sgpmwrlosB4.b1 |
| Description: | Several related and recurring problems with the SGP MWRs have been reported dating back to 1999. These problems were due to the occurrence of blackbody signals (in counts) that were half of those expected. The symptoms included noisy data (especially at Purcell), spikes in the data (especially at Vici), negative brightness temperatures, and apparent loss of serial communication between the computer and the radiometer, which results in a self-termination of the MWR program (especially at the CF). Because these all initially appeared to be hardware-related problems, the instrument mentor and SGP site operations personnel (1) repeatedly cleaned and replaced the fiber optic comm. components, (2) swapped radiometers, (3) sent radiometers back to Radiometrics for evaluation (which has not revealed any instrument problems), and (4) reconfigured the computer's operating system. Despite several attempts to isolate and correct it, the problem persisted. It became apparent that some component of the Windows98 configuration conflicted with the DOS-based MWR program or affected the serial port or the contents of the serial port buffer. This problem was finally corrected by upgrading the MWR software with a new Windows-compatible program. |
| Measurements: | sgpmwrlosB4.b1:
sgpmwrlosB4.a1:
|
| Start Date | Start Time | End Date | End Time |
|---|---|---|---|
| 12/23/1999 | 0600 | 07/10/2002 | 1700 |
| Subject: | SGP/MWR/B5 - Intermittent Negative Sky Brightness Temperatures |
| DataStreams: | sgpmwrlosB5.a1, sgpmwrlosB5.b1 |
| Description: | Several related and recurring problems with the SGP MWRs have been reported dating back to 1999. These problems were due to the occurrence of blackbody signals (in counts) that were half of those expected. The symptoms included noisy data (especially at Purcell), spikes in the data (especially at Vici), negative brightness temperatures, and apparent loss of serial communication between the computer and the radiometer, which results in a self-termination of the MWR program (especially at the CF). Because these all initially appeared to be hardware-related problems, the instrument mentor and SGP site operations personnel (1) repeatedly cleaned and replaced the fiber optic comm. components, (2) swapped radiometers, (3) sent radiometers back to Radiometrics for evaluation (which has not revealed any instrument problems), and (4) reconfigured the computer's operating system. Despite several attempts to isolate and correct it, the problem persisted. It became apparent that some component of the Windows98 configuration conflicted with the DOS-based MWR program or affected the serial port or the contents of the serial port buffer. This problem was finally corrected by upgrading the MWR software with a new Windows-compatible program. |
| Measurements: | sgpmwrlosB5.a1:
sgpmwrlosB5.b1:
|
| Start Date | Start Time | End Date | End Time |
|---|---|---|---|
| 10/28/1998 | 0000 | 01/24/2003 | 1659 |
| Subject: | SGP/MWR/B1 - min/max/delta values incorrect |
| DataStreams: | sgpmwrlosB1.b1 |
| Description: | 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. |
| Measurements: | sgpmwrlosB1.b1:
|
| Start Date | Start Time | End Date | End Time |
|---|---|---|---|
| 10/28/1998 | 0000 | 02/10/2003 | 2359 |
| Subject: | SGP/MWR/B4 - min/max/delta values incorrect |
| DataStreams: | sgpmwrlosB4.b1 |
| Description: | 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. |
| Measurements: | sgpmwrlosB4.b1:
|
| Start Date | Start Time | End Date | End Time |
|---|---|---|---|
| 01/16/1998 | 0000 | 02/10/2003 | 2359 |
| Subject: | SGP/MWR/B5 - min/max/delta values incorrect |
| DataStreams: | sgpmwrlosB5.b1 |
| Description: | 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. |
| Measurements: | sgpmwrlosB5.b1:
|
| Start Date | Start Time | End Date | End Time |
|---|---|---|---|
| 07/03/2003 | 0000 | 08/27/2003 | 2359 |
| Subject: | SGP/MWR/B1 - thermal instability |
| DataStreams: | sgpmwrlosB1.a1, sgpmwrlosB1.b1 |
| Description: | During periods of high ambient temperature, the instrument may have been thermally unstable. |
| Measurements: | sgpmwrlosB1.a1:
sgpmwrlosB1.b1:
|
| Start Date | Start Time | End Date | End Time |
|---|---|---|---|
| 10/14/2003 | 1741 | 12/23/2004 | 2025 |
| Subject: | SGP/MWR/B4 - no air temperature signal |
| DataStreams: | sgpmwrlosB4.b1, sgpmwrtipB4.a1 |
| Description: | 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. |
| Measurements: | sgpmwrlosB4.b1:
sgpmwrtipB4.a1:
|
| Start Date | Start Time | End Date | End Time |
|---|---|---|---|
| 03/18/2004 | 1747 | 03/18/2004 | 2338 |
| 03/20/2004 | 1808 | 03/20/2004 | 1952 |
| Subject: | SGP/MWR/B5 - thermal instability |
| DataStreams: | sgpmwrlosB5.a1, sgpmwrtipB5.a1 |
| Description: | The mixer kinetic temperature oscillated with an amplitude of about 3 to 5K. This effected the water vapor and liquid content fields. It is not known what caused this behavior. The instrument was returned for upgrades on 4/2 and the problem has not since been observed. |
| Measurements: | sgpmwrlosB5.a1:
sgpmwrtipB5.a1:
|
| Start Date | Start Time | End Date | End Time |
|---|---|---|---|
| 02/12/1994 | 0000 | 12/31/1994 | 2359 |
| Subject: | SGP/MWR/B1/B4/B5 - Data dropouts due to serial comm problems |
| DataStreams: | sgpmwrlosB1.a1, sgpmwrlosB4.a1, sgpmwrlosB5.a1 |
| Description: | Conflicts between the drop shipper program and the MWR operation program resulted in serial communication problems which ultimately manifested as spikes and dropouts in the data. |
| Measurements: | sgpmwrlosB5.a1:
sgpmwrlosB1.a1:
sgpmwrlosB4.a1:
|
| Start Date | Start Time | End Date | End Time |
|---|---|---|---|
| 08/14/1995 | 0000 | 08/15/1995 | 2359 |
| 08/20/1995 | 0000 | 08/20/1995 | 2359 |
| 08/28/1995 | 0000 | 08/31/1995 | 2359 |
| 09/02/1995 | 0000 | 09/04/1995 | 2359 |
| 09/13/1995 | 0000 | 09/13/1995 | 2359 |
| Subject: | SGP/MWR/B1 - Loss of thermal stabilization |
| DataStreams: | sgp5mwravgB1.c1, sgpmwrlosB1.a0, sgpmwrlosB1.a1 |
| Description: | Periodically during August and September 1995 all microwave radiometers at the SGP CART generated error messages in the Site Operations Log like: Time: Sat Aug 19 18:41:20 1995 MWRLOS.C1, tkxc: Value above Maximum. This indicates that the temperature of the microwave hardware (specifically, the cross-coupler or "xc") exceeded its controlled temperature (47-52 deg C) at which point it was no longer thermally stabilized and the gain was uncontrolled. During these periods which typically last about 8 hours from about local noon until about sunset the data behave anomalously and should be considered invalid. Specifically the precipitable water vapor increases and the liquid water path decreases (and becomes SIGNIFICANTLY NEGATIVE (-0.1 mm) on clear sky days). The RMS noise level in the data also increases sharply. The 'Tkxc' field appears ONLY in the a0-level data and does NOT appear in either the a1 (mwrlos) or c1 (mwr5avg) files. Therefore THESE ANOMALOUS VALUES HAVE BEEN INCLUDED IN THE 5-MINUTE AVERAGES. The microwave hardware is thermally stabilized to about +/- 0.1 deg C by resistive heating. When the internal temperature rises above the set point the thermal stabilization of the instrument gain is lost. >From an examination of the component temperature data it appears that increasing the set point temperature to about 55 deg C (328 K) would prevent a re-ocurrance of this problem at the SGP. The manufacturer, Radiometrics, concurs that raising the set point will fix this problem and will not cause other problems. I will have to carefully examine the MCTEX data to determine whether this will be a problem for the TWP. The manufacturer and I had discussed this possibility prior to building the TWP MWRs (S/N 015, 016, and 017) and those instruments have set points above 50 deg C. Note that MWR 018 has a set point near 52 deg C (like the TWP models) but it still experienced a few loss-of-stabilization events. Note that the instruments with the lowest set points had the most loss-of-stabilization events. |
| Measurements: | sgpmwrlosB1.a1:
sgp5mwravgB1.c1:
sgpmwrlosB1.a0:
|
| Start Date | Start Time | End Date | End Time |
|---|---|---|---|
| 08/03/1995 | 0000 | 08/03/1995 | 2359 |
| 08/06/1995 | 0000 | 08/14/1995 | 2359 |
| 08/16/1995 | 0000 | 09/06/1995 | 2359 |
| Subject: | SGP/MWR/B5 - Loss of thermal stabilization |
| DataStreams: | sgp5mwravgB5.c1, sgpmwrlosB5.a0, sgpmwrlosB5.a1 |
| Description: | Periodically during August and September 1995 all microwave radiometers at the SGP CART generated error messages in the Site Operations Log like: Time: Sat Aug 19 18:41:20 1995 MWRLOS.C1, tkxc: Value above Maximum. This indicates that the temperature of the microwave hardware (specifically, the cross-coupler or "xc") exceeded its controlled temperature (47-52 deg C) at which point it was no longer thermally stabilized and the gain was uncontrolled. During these periods which typically last about 8 hours from about local noon until about sunset the data behave anomalously and should be considered invalid. Specifically the precipitable water vapor increases and the liquid water path decreases (and becomes SIGNIFICANTLY NEGATIVE (-0.1 mm) on clear sky days). The RMS noise level in the data also increases sharply. The 'Tkxc' field appears ONLY in the a0-level data and does NOT appear in either the a1 (mwrlos) or c1 (mwr5avg) files. Therefore THESE ANOMALOUS VALUES HAVE BEEN INCLUDED IN THE 5-MINUTE AVERAGES. The microwave hardware is thermally stabilized to about +/- 0.1 deg C by resistive heating. When the internal temperature rises above the set point the thermal stabilization of the instrument gain is lost. >From an examination of the component temperature data it appears that increasing the set point temperature to about 55 deg C (328 K) would prevent a re-ocurrance of this problem at the SGP. The manufacturer, Radiometrics, concurs that raising the set point will fix this problem and will not cause other problems. I will have to carefully examine the MCTEX data to determine whether this will be a problem for the TWP. The manufacturer and I had discussed this possibility prior to building the TWP MWRs (S/N 015, 016, and 017) and those instruments have set points above 50 deg C. Note that MWR 018 has a set point near 52 deg C (like the TWP models) but it still experienced a few loss-of-stabilization events. Note that the instruments with the lowest set points had the most loss-of-stabilization events. |
| Measurements: | sgpmwrlosB5.a1:
sgp5mwravgB5.c1:
sgpmwrlosB5.a0:
|
| Start Date | Start Time | End Date | End Time |
|---|---|---|---|
| 10/10/2004 | 1930 | 11/23/2004 | 1720 |
| Subject: | SGP/MWR/B4 - Heater problem |
| DataStreams: | sgpmwrlosB4.b1, sgpmwrtipB4.a1 |
| Description: | The heater does not appear to be operating properly when moisture is detected. The problem was corrected by adjusting the heater sensivity. |
| Measurements: | sgpmwrlosB4.b1:
sgpmwrtipB4.a1:
|
| Start Date | Start Time | End Date | End Time |
|---|---|---|---|
| 04/12/2002 | 1600 | 06/24/2005 | 2100 |
| Subject: | SGP/MWR/B1 - Reprocess: Revised Retrieval Coefficients |
| DataStreams: | sgp5mwravgB1.c1, sgpmwrlosB1.a1, sgpmwrlosB1.b1, sgpmwrtipB1.a1, sgpqmemwrcolB1.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 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. |
| Measurements: | sgpmwrlosB1.a1:
sgpmwrlosB1.b1:
sgp5mwravgB1.c1:
sgpmwrtipB1.a1:
sgpqmemwrcolB1.c1:
|
| Start Date | Start Time | End Date | End Time |
|---|---|---|---|
| 04/15/2002 | 2300 | 06/24/2005 | 2100 |
| Subject: | SGP/MWR/B4 - Reprocess: Revised Retrieval Coefficients |
| DataStreams: | sgp5mwravgB4.c1, sgpmwrlosB4.a1, sgpmwrlosB4.b1, sgpmwrtipB4.a1, sgpqmemwrcolB4.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 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. |
| Measurements: | sgpmwrlosB4.b1:
sgpmwrtipB4.a1:
sgpqmemwrcolB4.c1:
sgp5mwravgB4.c1:
sgpmwrlosB4.a1:
|
| Start Date | Start Time | End Date | End Time |
|---|---|---|---|
| 04/15/2002 | 2300 | 06/24/2005 | 2100 |
| Subject: | SGP/MWR/B5 - Reprocess: Revised Retrieval Coefficients |
| DataStreams: | sgp5mwravgB5.c1, sgpmwrlosB5.a1, sgpmwrlosB5.b1, sgpmwrtipB5.a1, sgpqmemwrcolB5.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 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. |
| Measurements: | sgpmwrlosB5.a1:
sgpmwrtipB5.a1:
sgpqmemwrcolB5.c1:
sgp5mwravgB5.c1:
sgpmwrlosB5.b1:
|
| Start Date | Start Time | End Date | End Time |
|---|---|---|---|
| 07/20/2005 | 1800 | 08/05/2005 | 1935 |
| Subject: | SGP/MWR/B1 - thermal instability |
| DataStreams: | sgpmwrlosB1.b1, sgpmwrtipB1.a1 |
| Description: | 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. |
| Measurements: | sgpmwrlosB1.b1:
sgpmwrtipB1.a1:
|
| Start Date | Start Time | End Date | End Time |
|---|---|---|---|
| 08/05/2005 | 2004 | 08/07/2005 | 0555 |
| Subject: | SGP/MWR/B1 - Reprocess: mixer temp adjustment |
| DataStreams: | sgpmwrlosB1.b1, sgpmwrtipB1.a1 |
| Description: | 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. |
| Measurements: | sgpmwrtipB1.a1:
sgpmwrlosB1.b1:
|
| Start Date | Start Time | End Date | End Time |
|---|---|---|---|
| 07/16/2002 | 2200 | 09/13/2005 | 1806 |
| Subject: | SGP/MWR/B1 - New software version (4.15) installed |
| DataStreams: | sgpmwrlosB1.b1, sgpmwrtipB1.a1 |
| Description: | 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. |
| Measurements: | sgpmwrtipB1.a1:
sgpmwrlosB1.b1:
|
| Start Date | Start Time | End Date | End Time |
|---|---|---|---|
| 07/09/2002 | 1700 | 09/13/2005 | 2121 |
| Subject: | SGP/MWR/B4 - New software version (4.15) installed |
| DataStreams: | sgpmwrlosB4.b1, sgpmwrtipB4.a1 |
| Description: | 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. |
| Measurements: | sgpmwrlosB4.b1:
sgpmwrtipB4.a1:
|
| Start Date | Start Time | End Date | End Time |
|---|---|---|---|
| 07/10/2002 | 1700 | 09/13/2005 | 2124 |
| Subject: | SGP/MWR/B5 - New software version (4.15) installed |
| DataStreams: | sgpmwrlosB5.b1, sgpmwrtipB5.a1 |
| Description: | 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. |
| Measurements: | sgpmwrtipB5.a1:
sgpmwrlosB5.b1:
|
| Start Date | Start Time | End Date | End Time |
|---|---|---|---|
| 09/28/2004 | 1729 | 11/23/2004 | 1713 |
| Subject: | SGP/MWR/B4 - Reprocess: wrong retrievals |
| DataStreams: | sgpmwrlosB4.a1, sgpmwrlosB4.b1, sgpmwrtipB4.a1, sgpqmemwrcolB4.c1 |
| Description: | 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. |
| Measurements: | sgpmwrlosB4.b1:
sgpmwrtipB4.a1:
sgpqmemwrcolB4.c1:
sgpmwrlosB4.a1:
|
| Start Date | Start Time | End Date | End Time |
|---|---|---|---|
| 10/12/2004 | 1725 | 11/12/2004 | 1903 |
| Subject: | SGP/MWR/B5 - Reprocess: wrong retrievals |
| DataStreams: | sgpmwrlosB5.a1, sgpmwrlosB5.b1, sgpmwrtipB5.a1, sgpqmemwrcolB5.c1 |
| Description: | 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. |
| Measurements: | sgpmwrlosB5.a1:
sgpmwrtipB5.a1:
sgpqmemwrcolB5.c1:
sgpmwrlosB5.b1:
|
| Start Date | Start Time | End Date | End Time |
|---|---|---|---|
| 06/01/2006 | 0000 | 08/21/2006 | 1100 |
| Subject: | SGP/MWR/B5 - Mixer temp unstable |
| DataStreams: | sgpmwrlosB5.b1, sgpmwrtipB5.a1 |
| Description: | 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. |
| Measurements: | sgpmwrtipB5.a1:
sgpmwrlosB5.b1:
|
| Start Date | Start Time | End Date | End Time |
|---|---|---|---|
| 07/16/2006 | 0000 | 07/22/2006 | 0600 |
| Subject: | SGP/MWR/B1 - Reprocessed: Corrected calibration |
| DataStreams: | sgpmwrB1.00, sgpmwrlosB1.b1, sgpmwrtipB1.a1 |
| Description: | 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. |
| Measurements: | sgpmwrtipB1.a1:
sgpmwrlosB1.b1:
sgpmwrB1.00:
|
| Start Date | Start Time | End Date | End Time |
|---|---|---|---|
| 06/19/2007 | 1600 | 10/16/2009 | 0300 |
| Subject: | SGP/MWR/B1 - 23.8-GHz brightness temperature slightly high |
| DataStreams: | sgp5mwravgB1.c1, sgpmwrlosB1.b1, sgpmwrtipB1.a1 |
| Description: | 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. |
| Measurements: | sgpmwrlosB1.b1:
sgp5mwravgB1.c1:
sgpmwrtipB1.a1:
|
| Start Date | Start Time | End Date | End Time |
|---|---|---|---|
| 09/02/2007 | 1500 | 04/01/2008 | 0000 |
| Subject: | SGP/MWR/B5 - Intermittent missing data |
| DataStreams: | sgpmwrlosB5.b1, sgpmwrtipB5.a1 |
| Description: | 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. |
| Measurements: | sgpmwrtipB5.a1:
sgpmwrlosB5.b1:
|
| Start Date | Start Time | End Date | End Time |
|---|---|---|---|
| 11/06/2007 | 0000 | 11/26/2007 | 1733 |
| Subject: | SGP/MWR/B1 - Calibration failure |
| DataStreams: | sgpmwrlosB1.b1, sgpmwrtipB1.a1 |
| Description: | 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. |
| Measurements: | sgpmwrtipB1.a1:
sgpmwrlosB1.b1:
|
| Start Date | Start Time | End Date | End Time |
|---|---|---|---|
| 03/18/2008 | 0600 | 03/19/2008 | 0500 |
| Subject: | SGP/MWR/B5 - Some rain events flagged |
| DataStreams: | sgpmwrlosB5.b1, sgpmwrtipB5.a1 |
| Description: | 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. |
| Measurements: | sgpmwrtipB5.a1:
sgpmwrlosB5.b1:
|
| Start Date | Start Time | End Date | End Time |
|---|---|---|---|
| 07/24/1999 | 2000 | 07/26/1999 | 1651 |
| 07/30/1999 | 2100 | 08/01/1999 | 1452 |
| 06/01/2000 | 1839 | 06/05/2000 | 1800 |
| 07/03/2000 | 2239 | 07/05/2000 | 1651 |
| 08/05/2000 | 1736 | 08/07/2000 | 1857 |
| 08/09/2000 | 1300 | 09/19/2000 | 1808 |
| 09/23/2000 | 0436 | 09/25/2000 | 1257 |
| 12/31/2000 | 1645 | 01/02/2001 | 1700 |
| 07/13/2001 | 1550 | 07/16/2001 | 1515 |
| 01/31/2002 | 0047 | 02/05/2002 | 1657 |
| 06/28/2002 | 1023 | 07/09/2002 | 1650 |
| 12/14/2002 | 0700 | 12/20/2002 | 1719 |
| 03/04/2003 | 1735 | 03/07/2003 | 1708 |
| 06/06/2003 | 0046 | 06/09/2003 | 1703 |
| 09/23/2003 | 1948 | 09/25/2003 | 1842 |
| 10/09/2003 | 2224 | 10/14/2003 | 1741 |
| 12/15/2003 | 1130 | 12/18/2003 | 1716 |
| 05/23/2004 | 2003 | 05/25/2004 | 1729 |
| 12/24/2004 | 0718 | 12/27/2004 | 1435 |
| 06/18/2005 | 1521 | 06/20/2005 | 1304 |
| 09/30/2005 | 0405 | 10/03/2005 | 1359 |
| 10/07/2005 | 2313 | 10/11/2005 | 1400 |
| 10/12/2005 | 0041 | 10/14/2005 | 1318 |
| 10/14/2005 | 1344 | 10/28/2005 | 1537 |
| 10/28/2005 | 2356 | 10/31/2005 | 1756 |
| 11/05/2005 | 0214 | 11/07/2005 | 1529 |
| 11/17/2005 | 1517 | 06/11/2007 | 1855 |
| 05/27/2008 | 0429 | 06/03/2008 | 1714 |
| 10/03/2008 | 0520 | 10/06/2008 | 1205 |
| 10/31/2008 | 1413 | 11/03/2008 | 1318 |
| Subject: | SGP/MWR/B4 - Missing data |
| DataStreams: | sgpmwrlosB4.b1, sgpmwrtipB4.a1 |
| Description: | Data are missing and unrecoverable. |
| Measurements: | sgpmwrlosB4.b1:
sgpmwrtipB4.a1:
|
| Start Date | Start Time | End Date | End Time |
|---|---|---|---|
| 03/28/1998 | 1959 | 04/08/1998 | 1626 |
| 07/07/1998 | 1959 | 07/15/1998 | 1823 |
| 07/18/1998 | 1900 | 07/29/1998 | 1944 |
| 09/04/1998 | 1859 | 09/09/1998 | 1848 |
| 12/15/1998 | 2153 | 12/17/1998 | 1926 |
| 01/17/1999 | 0549 | 01/19/1999 | 1829 |
| 06/23/1999 | 1429 | 06/25/1999 | 1945 |
| 07/23/1999 | 1900 | 07/27/1999 | 1537 |
| 07/27/1999 | 1759 | 07/29/1999 | 2153 |
| 07/30/1999 | 1900 | 08/01/1999 | 1453 |
| 09/11/1999 | 0616 | 09/13/1999 | 1456 |
| 09/13/1999 | 1700 | 09/15/1999 | 2130 |
| 09/17/1999 | 1303 | 10/27/1999 | 1716 |
| 02/18/2000 | 1700 | 02/21/2000 | 1522 |
| 09/01/2000 | 2000 | 09/05/2000 | 1636 |
| 12/26/2000 | 2343 | 01/02/2001 | 1713 |
| 01/12/2001 | 1900 | 01/15/2001 | 1542 |
| 11/10/2001 | 1957 | 11/12/2001 | 1629 |
| 01/27/2003 | 1413 | 01/31/2003 | 1734 |
| 03/03/2003 | 1130 | 03/05/2003 | 1904 |
| 06/14/2003 | 2229 | 06/19/2003 | 1548 |
| 08/18/2003 | 1131 | 08/20/2003 | 1700 |
| 10/08/2003 | 0703 | 10/10/2003 | 1545 |
| 10/10/2003 | 1624 | 10/15/2003 | 1622 |
| 10/15/2003 | 1700 | 10/17/2003 | 1618 |
| 12/24/2003 | 2341 | 12/26/2003 | 1741 |
| 02/16/2004 | 1131 | 02/18/2004 | 1844 |
| 03/31/2004 | 1917 | 05/07/2004 | 1703 |
| 09/13/2004 | 1130 | 09/15/2004 | 1559 |
| 11/13/2004 | 2032 | 11/15/2004 | 1757 |
| 11/24/2004 | 1834 | 11/26/2004 | 1729 |
| 12/04/2004 | 1344 | 12/06/2004 | 1846 |
| 12/25/2004 | 1825 | 12/27/2004 | 1434 |
| 07/09/2005 | 1114 | 07/11/2005 | 1313 |
| 10/24/2005 | 1043 | 10/26/2005 | 1623 |
| 11/01/2005 | 0911 | 11/09/2005 | 1946 |
| 11/10/2005 | 0356 | 11/23/2005 | 1440 |
| 11/29/2005 | 0924 | 12/06/2005 | 1749 |
| 12/06/2005 | 2100 | 12/09/2005 | 1736 |
| 12/09/2005 | 2333 | 12/12/2005 | 1429 |
| 08/21/2006 | 1800 | 06/11/2007 | 1953 |
| 09/02/2007 | 1451 | 09/07/2007 | 1540 |
| 09/14/2007 | 1546 | 09/17/2007 | 1811 |
| 09/18/2007 | 0525 | 09/26/2007 | 1320 |
| 10/05/2007 | 0331 | 10/09/2007 | 1549 |
| 11/03/2007 | 2345 | 11/05/2007 | 1620 |
| 11/10/2007 | 0009 | 11/13/2007 | 1725 |
| 11/17/2007 | 2345 | 11/19/2007 | 1411 |
| 11/21/2007 | 1900 | 12/06/2007 | 2100 |
| 12/06/2007 | 2120 | 12/13/2007 | 1836 |
| 01/19/2008 | 1024 | 01/23/2008 | 1438 |
| 04/15/2008 | 1304 | 04/17/2008 | 1312 |
| 04/19/2008 | 0116 | 04/21/2008 | 1310 |
| 05/31/2008 | 1809 | 06/04/2008 | 1915 |
| 10/03/2008 | 0842 | 10/06/2008 | 1209 |
| 12/12/2008 | 1847 | 12/15/2008 | 1441 |
| 04/03/2009 | 0925 | 04/06/2009 | 1211 |
| Subject: | SGP/MWR/B5 - Missing data |
| DataStreams: | sgpmwrlosB5.b1 |
| Description: | Data are missing and unrecoverable. |
| Measurements: | sgpmwrlosB5.b1:
|
| Start Date | Start Time | End Date | End Time |
|---|---|---|---|
| 12/15/2008 | 1400 | 12/16/2008 | 1100 |
| Subject: | SGP/MWR/B1 - Noisy data |
| DataStreams: | sgpmwrlosB1.b1, sgpmwrtipB1.a1 |
| Description: | 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. |
| Measurements: | sgpmwrlosB1.b1:
sgpmwrtipB1.a1:
|
| Start Date | Start Time | End Date | End Time |
|---|---|---|---|
| 12/07/2008 | 0000 | 12/29/2008 | 0000 |
| Subject: | SGP/MWR/B4 - Occasional spikes in data |
| DataStreams: | sgpmwrlosB4.b1, sgpmwrtipB4.a1 |
| Description: | 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. |
| Measurements: | sgpmwrlosB4.b1:
sgpmwrtipB4.a1:
|
| Start Date | Start Time | End Date | End Time |
|---|---|---|---|
| 07/26/1999 | 1859 | 08/01/1999 | 1449 |
| 09/05/1999 | 0300 | 09/09/1999 | 1350 |
| 12/16/2000 | 0000 | 12/18/2000 | 2202 |
| 01/14/2001 | 1245 | 01/16/2001 | 1543 |
| 02/02/2001 | 1717 | 02/05/2001 | 1627 |
| 07/13/2001 | 2059 | 07/17/2001 | 1840 |
| 07/20/2001 | 1700 | 07/22/2001 | 1930 |
| 01/20/2003 | 0259 | 01/23/2003 | 1632 |
| 01/24/2003 | 1713 | 03/06/2003 | 2033 |
| 05/13/2003 | 0240 | 05/15/2003 | 1618 |
| 05/26/2003 | 0142 | 05/29/2003 | 1608 |
| 06/07/2003 | 0228 | 06/11/2003 | 1646 |
| 01/11/2004 | 0001 | 01/13/2004 | 1924 |
| 02/15/2004 | 0859 | 02/19/2004 | 1646 |
| 02/24/2004 | 1950 | 04/01/2004 | 1909 |
| 04/21/2004 | 2121 | 04/23/2004 | 1658 |
| 04/24/2004 | 2048 | 04/26/2004 | 1723 |
| 05/31/2005 | 2000 | 06/02/2005 | 1446 |
| 09/17/2005 | 1949 | 09/19/2005 | 1336 |
| 12/31/2005 | 0033 | 01/03/2006 | 1420 |
| 02/06/2006 | 0907 | 02/08/2006 | 1651 |
| 04/28/2006 | 1421 | 05/01/2006 | 1411 |
| 07/22/2006 | 0557 | 07/27/2006 | 1338 |
| 09/20/2006 | 1824 | 06/19/2007 | 1632 |
| 11/26/2007 | 1733 | 11/28/2007 | 2122 |
| 11/28/2007 | 2203 | 01/30/2008 | 1804 |
| 07/09/2008 | 0304 | 07/11/2008 | 1635 |
| 07/12/2008 | 0836 | 07/14/2008 | 1427 |
| 12/12/2008 | 1342 | 12/15/2008 | 1435 |
| 04/10/2009 | 0029 | 04/13/2009 | 1220 |
| 06/16/2009 | 0235 | 06/18/2009 | 1617 |
| Subject: | SGP/MWR/B1 - Missing data |
| DataStreams: | sgpmwrlosB1.b1 |
| Description: | Data are missing and unrecoverable. |
| Measurements: | sgpmwrlosB1.b1:
|
| Start Date | Start Time | End Date | End Time |
|---|---|---|---|
| 01/15/2009 | 1300 | 01/16/2009 | 0500 |
| Subject: | SGP/MWR/B1 - Noisy data |
| DataStreams: | sgpmwrlosB1.b1, sgpmwrtipB1.a1 |
| Description: | After a software crash data were very noisy. |
| Measurements: | sgpmwrlosB1.b1:
sgpmwrtipB1.a1:
|
| Start Date | Start Time | End Date | End Time |
|---|---|---|---|
| 04/05/2009 | 0000 | 09/01/2009 | 0000 |
| Subject: | SGP/MWR/B1 - Increased noise level |
| DataStreams: | sgpmwrlosB1.b1, sgpmwrtipB1.a1 |
| Description: | 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. |
| Measurements: | sgpmwrlosB1.b1:
sgpmwrtipB1.a1:
|
| Start Date | Start Time | End Date | End Time |
|---|---|---|---|
| 12/22/1993 | 0000 | 02/28/1994 | 2359 |
| 02/12/1994 | 0000 | 01/05/1995 | 2359 |
| Subject: | Reprocess: Effect of BBSS ground check on MWR tuning functions |
| DataStreams: | DsgpmwrlosB1.a0, DsgpmwrlosB1.a1, sgpmwrlosB1.a1 |
| Description: | Due to concern over the impact of the Ground Check (a one-point calibration applied to the Vaisala sonde prior to launch) on the MWR tuning functions, I have recalculated the tuning functions without the ground check. The change in the tuning functions is slight and has only a very small (maximum of 1%) impact on the precipitable water vapor and cloud liquid water path values provided by the ARM microwave radiometers. TUNING FUNCTIONS The tuning functions relate microwave brightness temperatures measured by the the radiometer to those computed from simultaneous radiosondes using a model of microwave radiation transfer. The tuning functions are necessary to permit the use of the retrieval functions for precipitable water vapor and cloud liquid water which are based on the model calculations. The tuning functions are dependent only on the model; they are independent of the location and of the instrument (assuming it is properly calibrated). METHODOLOGY Barry Lesht, the BBSS instrument mentor, provided me with 325 soundings from the SGP central facility covering the period October 1992 - December 1993 from which he had removed the effect of the ground check. For each of these soundings I computed the microwave brightness temperatures at the frequencies used by the ARM microwave radiometers. Of these, 91 were determined to have occured during periods when the sky was clear and horizontally homogeneous on the basis of the standard deviation of the measured brightness temperature of the liquid-sensitive channel of the radiometer being less than 0.5 K for the period 10 minutes prior until 30 minutes subsequent to the sonde launch. The mean of the brightness temperatures measured during this time period were then used in a linear regression to determine the intercept and slope of the tuning functions. RESULTS: The new tuning functions are: 23.8 GHz: TB_model = 0.789 + 0.915 TB_measured (R2 = 0.994) 31.4 GHz: TB_model = 1.142 + 0.910 TB_measured (R2 = 0.988) These were applied to the MWR data acquired during the period October 1992 through December 1993 and compared with previous values. Only for values of PWV > 3 cm was the effect of the new tuning functions as much as 1%. For the 91 clear-sky soundings, the RMS difference between the preciptable water vapor from the MWR and from the BBSS was 0.1 cm; the mean difference was 0.00 cm. For 59 soundings during June 1993 (clear and cloudy sky), the mean difference in the PWV computed from the radiosondes (No ground check - ground check) was 0.05 cm; the RMS of the difference was 0.08 cm. Other observations/measurements impacted by this problem: qmemwrlos Suggested Corrections of the Problem: (e.g. change calibration factor and recompute, flag data with this comment, etc.) 1. The new tuning functions were implemented on all SGP MWRs on 5 Jan 1995. 2. The MWR data from Oct 92 - Dec 93 have been recalculated by the mentor and are available from him (as ten-minute averages in ASCII format) upon request. 3. A computer code has been provided by the mentor to the ARM Experiment Center to duplicate this reprocessing, if the PRB so desires. |
| Measurements: | sgpmwrlosB1.a1:
DsgpmwrlosB1.a0:
DsgpmwrlosB1.a1:
|
| Start Date | Start Time | End Date | End Time |
|---|---|---|---|
| 12/07/1995 | 0300 | 12/10/1995 | 0600 |
| Subject: | Precipitable Water Vapor (PWV) values at Hillsboro |
| DataStreams: | sgp5mwravgB1.c1, sgpmwrlosB1.a0, sgpmwrlosB1.a1 |
| Description: | DQR No: Platform: sgpmwrlos, sgp5mwravg
Subject: Precipitable Water Vapor (PWV) values at Hillsboro
Date Submitted:
Submitted By: JIM LILJEGREN _X_ Instrument Mentor
___ EST Member
___ Science Team Member
___ Other _____________________________
For questions or problems, please contact the ARM Experiment Center at
509-375-6898 or via email at dqr@arm.gov.
Platform/Measurement:
What level data: a0,a1,c1
What location was the data collected at: SGP B1 (Hillsboro, KS)
Period of time in question
Begin Date 12/07/95 Time 03:00 (GMT)
End Date 12/07/95 Time 16:00 (GMT)
Begin Date 12/08/95 Time 20:00 (GMT)
End Date 12/10/95 Time 06:00 (GMT)
Data should be labeled:
___ questionable _X_ All data fields affected
_X_ incorrect ___ Only some data fields affected
_X_ wrong calibration
___ others
Discussion of Problem:
The precipitable water vapor was negative which is unreasonable. At the
same time the brightness temperature in the 23.8 GHz was less than that
in the 31.4 GHz for apparently clear skies. This is also unreasonable.
The calibration needs to be checked and updated.
Other observations/measurements impacted by this problem:
none
Suggested Corrections of the Problem: (e.g. change calibration factor and
recompute, flag data with this comment, etc.)
Correct calibration.
Data Processing Notes Date |
| Measurements: | sgpmwrlosB1.a1:
sgp5mwravgB1.c1:
sgpmwrlosB1.a0:
|
| Start Date | Start Time | End Date | End Time |
|---|---|---|---|
| 01/13/1996 | 0000 | 01/19/1996 | 2359 |
| Subject: | SGP/MWR/B1/B5 - Calibration questionable |
| DataStreams: | sgpmwrlosB1.a0, sgpmwrlosB1.a1, sgpmwrlosB5.a0, sgpmwrlosB5.a1 |
| Description: | At the present time, calibrations at B1 and B5 appear out of date. SGP-B1 (Hillsboro, KS) Precipitable vapor amounts occasionally negative - calibration needs to be checked when sky becomes clear. Data quality is questionable. Precipitable vapor amounts about 0.6 cm less than integrated soundings. SGP-B5 (Morris, OK) Data from this instrument are missing for 12-15 Jan. Reason unknown. Because precipitable vapor amount was negative during 7-8 Jan, calibration is still suspect. Liquid water path appears positive for periods when sky is clear (positive bias). Data quality is questionable. Precipitable vapor amounts 0.3-0.5 cm less than integrated soundings. |
| Measurements: | sgpmwrlosB5.a1:
sgpmwrlosB1.a1:
sgpmwrlosB1.a0:
sgpmwrlosB5.a0:
|
| Start Date | Start Time | End Date | End Time |
|---|---|---|---|
| 02/02/1996 | 2130 | 02/06/1996 | 1900 |
| Subject: | MWR serial communications problems at Vici |
| DataStreams: | sgpmwrlosB4.a0, sgpmwrlosB4.a1 |
| Description: | DQR No: Platform: sgpmwrlosB4
Date Submitted: 02/06/96
Submitted By: Jim Liljegren _X_ Instrument Mentor
___ EST Member
___ Science Team Member
___ Other _____________________________
For questions or problems, please contact the ARM Experiment Center at
509-375-6898 or via email at problems@arm.gov.
Platform/Measurement: sgpmwrlosB4 and derivatives
What level data: (raw,a0,a1,b1,c1 etc):
What location was the data collected at: B4
Period of time in question
Begin Date 2/2/96 Time 21:30 (GMT)
End Date 2/6/96 Time 19:00 (GMT)
Data should be labeled:
___ questionable ___ All data fields affected
___ incorrect ___ Only some data fields affected
___ wrong calibration
___ others
Discussion of Problem:
Serial communications errors between MWR and computer due to "lock up"
of fiber optic driver.
On 2/5/96 I received a call from the Vici operator (Debbie) that the
MWR was reporting COM TIMEOUT messages. She said she noticed this when
she arrived at the site on Monday morning, so the problem could have
begun Friday evening after she left.
I directed her to check the serial data cable connections. She
reported that all seemed tight and informed Site Operations that a
service call was necessary.
On 2/6/96 Tim Groves contacted me from Vici and reported that a fiber
optic driver was "locked up" and that he had reset the device and re-
established communications with the MWR.
Tim also reported that the MWR was not indicating proper internal
temperatures and would not exit its initialization/warmup phase as a
result. (One of the blackbody temperatures was 0 Kelvins.) I directed
him in testing the voltages of these RTDs read by the MWR A/D using his
computer. They checked out OK. I then directed Tim to reboot the MWR
computer. This resolved the problem - the temperatures were properly
indicated and the MWR proceeded to begin data acquisition.
Other observations/measurements impacted by this problem:
Suggested Corrections of the Problem: (e.g. change calibration factor and
recompute, flag data with this comment, etc.) |
| Measurements: | sgpmwrlosB4.a0:
sgpmwrlosB4.a1:
|
| Start Date | Start Time | End Date | End Time |
|---|---|---|---|
| 02/26/1996 | 0000 | 04/05/1996 | 2359 |
| Subject: | calibration checked, noisy 31 GHz channel |
| DataStreams: | sgpmwrlosB4.a0, sgpmwrlosB4.a1 |
| Description: | DQR No: Platform: sgpmwrlosB4
Date Submitted: 02/25/96
Submitted By: Jim Liljegren _X_ Instrument Mentor
___ EST Member
___ Science Team Member
___ Other _____________________________
For questions or problems, please contact the ARM Experiment Center at
509-375-6898 or via email at problems@arm.gov.
Platform/Measurement: sgpmwrlosB4 and derivatives
What level data: (raw,a0,a1,b1,c1 etc):
What location was the data collected at: B4
Period of time in question
Begin Date 2/26/96 Time (GMT)
End Date ongoing Time (GMT)
Data should be labeled:
_X_ questionable ___ All data fields affected
___ incorrect ___ Only some data fields affected
___ wrong calibration
___ others ___ Valid and Releasable
Discussion:
I have reduced the TIP data from 2/10-2/14 and found that the
calibration of the microwave radiometer at the SGP Vici boundary
facility (B4) does NOT need to be changed.
The results are as follows:
Date Tnd_23 Tnd_31
Feb 96 163.56 168.47
Sep 95 163.55 168.99
However, the deviations about the mean are considerably larger in the
31 GHz channel than the 23 GHz: 0.82 vs 0.14 K, respectively.
Consequently the 31 GHz brightness temperature also shows considerably
greater variation than the 23 GHz brightness temperature.
Although the precipitable vapor continues to show good agreement
with the colocated soundings, I recommend caution in using these
data.
Since this instrument has been in service since June 1992, I have
submitted a Problem Identification Form (PIF) recommending that the
analog electronics circuit board be swapped out and the instrument
re-calibrated. If this fails to correct the problem then the
instrument will be returned to the manufacturer for repair.
Other observations/measurements impacted by this problem:
Suggested Corrections of the Problem: (e.g. change calibration factor and
recompute, flag data with this comment, etc.) |
| Measurements: | sgpmwrlosB4.a0:
sgpmwrlosB4.a1:
|
| Start Date | Start Time | End Date | End Time |
|---|---|---|---|
| 02/12/1994 | 0000 | 04/04/1996 | 2359 |
| Subject: | SGP/MWR/B1/B4/B5 - Reprocess: Error in MWR calibration |
| DataStreams: | sgpmwrlosB1.a0, sgpmwrlosB1.a1, sgpmwrlosB4.a0, sgpmwrlosB4.a1, sgpmwrlosB5.a0, sgpmwrlosB5.a1 |
| Description: | The effect of this error is small. At most, it results in a bias of
about -0.015 cm in precipitable water vapor and -0.015 mm in liquid
water path during clear sky conditions. The error is largest when the
brightness temperatures are small (i.e. clear skies and low PWV).
The error results from failing to correctly account for the effect of
the Teflon window covering the radiometer mirror. Although the
contribution of the window is subtracted when the tip curve data are
reduced to determine the true zenith brightness temperature, it is not
added back in when the zenith brightness temperature is used to
calibrate the noise diode. This would still not be a problem if the
contribution of the window where not subtracted (again) during zenith
line-of-sight (LOS) operations. But it is and the net effect is to
subtract the contribution of the window twice.
The calibrations ('Noise Injection Temperatures') are off by a factor
of 1.00164 and 1.00217 for the 23.8 and 31.4 GHz frequencies,
respectively.
The magnitude of the error is equal to the emissivity of the window
multiplied by the difference between the brightness temperature and the
temperature of the window. The latter is taken to be equal to the
temperature of the internal blackbody target (which is about 10 deg C
above ambient.) The emissivity of the window is 0.00164 at 23.8 GHz
and 0.00217 at 31.4 GHz. For a reference temperature of 292.6 K and
brightness temperatures of 32.3 and 20.8 K at 23.8 and 31.4 GHz
respectively, this amounts to errors of -0.43 and -0.59 K at the
respective frequencies. The average PWV for this date (5 April 1995)
was 1.4 cm.
At higher levels of PWV and for cloudy conditions, the brightness
temperatures are higher and so the error is smaller.
I will adjust the calibrations of all SGP radiometers to account
for this problem by the end of tomorrow (4 April 1996). |
| Measurements: | sgpmwrlosB5.a1:
sgpmwrlosB1.a1:
sgpmwrlosB4.a0:
sgpmwrlosB1.a0:
sgpmwrlosB5.a0:
sgpmwrlosB4.a1:
|
| Start Date | Start Time | End Date | End Time |
|---|---|---|---|
| 02/12/1994 | 0000 | 04/04/1996 | 2359 |
| Subject: | SGP/MWR/B1/B4/B5 - Reprocess: MWR Tuning Functions |
| DataStreams: | sgpmwrlosB1.a0, sgpmwrlosB1.a1, sgpmwrlosB4.a0, sgpmwrlosB4.a1, sgpmwrlosB5.a0, sgpmwrlosB5.a1 |
| Description: | The 'tuning functions' used to adjust the equivalent brightness
temperatures (TBs) measured by the ARM microwave radiometers (MWRs) are
now believed to be both incorrect and unnecessary. They should no longer
be used and the data (going back to 1992) that incorporated them should
be reprocessed. By eliminating these tuning functions the radiometer
retrievals would be independent of the soundings.
BACKGROUND
A recent comparison by Barry Lesht (ANL) of the precipitable water
vapor (PWV) retrieved from the MWR-measured brightness temperatures
against PWV derived by integrating along the trajectory of radiosonde
ascents has revealed that the MWR values are about 90% of those derived
from the soundings. This is directly attributable to the slope of the
tuning function for the vapor-sensing channel (23.8 GHz) of 0.915 which
is applied to the measured brightness temperatures prior to retrieval
of PWV.
The rationale behind the use of the tuning functions is that the
radiation model (Liebe 87), on which the retrieval is based, is
imperfect whereas the radiosondes represent 'ground truth.' Thus the
observed brightness temperatures must be adjusted to match those
calculated with the model using co-located soundings so that the
retrieval yields precipitable vapor amounts that agree with the
soundings.
Tuning functions were developed for the present ARM MWRs using
co-located soundings launched between October 1992 and December 1993.
These were adjusted slightly in January 1995 to account for the effects
of the 1-point calibration check performed prior to launch (see DQR
P950110.1):
23.8 GHz: TB_model = 0.789 + 0.915 TB_measured (R2 = 0.998)
31.4 GHz: TB_model = 1.142 + 0.910 TB_measured (R2 = 0.984)
However, repeating this exercise for soundings launched during 1994 and
1995 (excepting those that were mis-calibrated by the manufacturer; see
D960229.1) it now appears that the model-calculated
brightness temperatures are in much closer agreement with the measured
values and that the tuning functions account more for variations in the
radiosonde calibration than for any deficiencies in the radiation
model.
Consequently, it appears that the present tuning functions are
incorrect and bias the retrieved PWV low by 10%. In addition, given
the present agreement between measured and modeled brightness
temperatures, the tuning functions are also unnecessary.
METHODOLOGY
Brightness temperatures measured with microwave radiometer (MWR) serial
number 10, which was deployed at the central facility in December 1993,
have been compared against calculations using measurements from the
co-located Balloon-Borne Sounding System (BBSS). The results are
summarized in two tables. In each table, the calibration dates of the
sondes and MWR are listed as well as the time period and number of
samples included in each regression. Each MWR sample is a 40-minute
average, centered on the time of the sonde launch, of the microwave
brightness temperature. In order to include only clear sky conditions,
samples for which the standard deviation of the liquid-sensing (31.4
GHz) channel exceeded 0.3 K were eliminated. To assure that the water
vapor was reasonably homogeneous horizontally, samples for which the
standard deviation in the vapor-sensing (23.8 GHz) channel exceeded 0.4
K (in 1995) or 0.5 K (in 1994) were eliminated. The 1994 threshold is
larger in order to increase the number of samples and reduce the
standard error in the results.
The microwave radiometer measurements used in this comparison have been
reprocessed to account for calibration changes and other problems (see
P940813.1)
TB vs PWV
The first table is a comparison of microwave brightness temperature
(TB_mwr) regressed against the precipitable water vapor (PWV) computed
by integrating along the trajectory of the radiosonde ascent. The
sondes launched during May - December 1994 are compared against two
sets of MWR data; the first uses the May 1994 calibration, and the
second uses the calibration of July 1994. A comparison is also made of
TB_model vs PWV ('Liebe87') for reference.
The intercepts indicate the contribution due to molecular oxygen (i.e.
the tail of the 60 GHz line) which is affected by temperature and
pressure. Note that the 'Liebe87' intercepts vary seasonally as the
temperature changes. Note also that the effect of MWR calibration
changes is most evident in the intercept: offsets of 1-2 K are
observed. Because the MWR calibration values represent the slope of
the radiometer equation (see Appendix), the magnitude of the offset is
largest at 0 K (i.e. the intercept) and declines to zero at ambient
temperature (~290 K).
The slope of the regression is essentially unaffected by the MWR
calibration. Variations in the slope of the regression correlate with
sonde calibration date. The sondes calibrated in May 1994 or later
appear to yield much closer agreement between the measured brightness
temperatures and those calculated with the Liebe 87 model than those
calibrated in January 1994 or earlier, with which the present tuning
functions were developed.
TABLE 1. Microwave brightness temperature vs. precipitable water vapor
Relationship: TB_mwr (K) = intercept (K) + slope (K/cm) * PW_sonde (cm)
Standard Error of the intercepts and slopes are given in parentheses.
Date of Date of Period ------ 23.8 GHz ----- ----- 31.4 GHz -----
Sonde Cal MWR tip Covered N intercept slope intercept slope
1991-93 92-93 Oct92-Dec93 91 6.7 14.7 8.1 5.3
1992,93 Dec 93 Jan-Feb 94 85 6.9(0.19) 15.8(0.26) 8.8(0.13) 5.6(0.17)
1992,93 Liebe87 Jan-Feb 94 85 6.5(0.02) 13.8(0.03) 8.9(0.07) 4.5(0.09)
Jun 93 Dec 93 Apr 94 16 10.6(1.11) 14.8(0.55) 10.1(0.51) 5.6(0.25)
Jun 93 Liebe87 Apr 94 16 6.9(0.05) 13.6(0.02) 8.1(0.09) 5.0(0.05)
1992,93 May 94 May-Jun 94 48 7.0(1.03) 14.9(0.45) 7.8(0.41) 5.7(0.17)
1992,93 Jul 94 May-Jun 94 48 5.1(1.03) 14.9(0.44) 6.6(0.39) 5.7(0.17)
1992,93 Liebe87 May-Jun 94 48 7.1(0.11) 13.5(0.05) 8.4(0.16) 4.9(0.07)
Jan 94 Dec 93 Feb-May 94 95 7.6(0.27) 14.3(0.14) 8.5(0.15) 5.5(0.08)
Jan 94 Liebe87 Feb-May 94 95 6.9(0.05) 13.6(0.02) 8.1(0.09) 5.0(0.05)
May 94 May 94 Jun-Aug 94 78 12.3(1.04) 13.0(0.34) 11.0(0.39) 4.8(0.13)
May 94 Jul 94 Jun-Aug 94 78 10.3(1.04) 13.1(0.34) 9.8(0.39) 4.8(0.13)
May 94 Liebe87 Jun-Aug 94 78 7.8(0.22) 13.3(0.07) 8.6(0.29) 4.9(0.10)
Jun 94 May 94 Jul-Dec 94 57 8.3(0.37) 13.6(0.21) 8.8(0.19) 5.2(0.11)
Jun 94 Jul 94 Jul-Dec 94 57 6.4(0.37) 13.6(0.21) 7.7(0.18) 5.2(0.10)
Jun 94 Liebe87 Jul-Dec 94 57 6.9(0.08) 13.5(0.04) 8.3(0.10) 4.9(0.06)
Aug 94 May 94 Sep-Dec 94 90 7.4(0.15) 13.5(0.09) 8.8(0.11) 5.1(0.07)
Aug 94 Jul 94 Sep-Dec 94 90 5.5(0.14) 13.6(0.09) 7.8(0.12) 5.0(0.07)
Aug 94 Liebe87 Sep-Dec 94 90 6.8(0.05) 13.6(0.03) 8.6(0.09) 4.9(0.06) |
| Measurements: | sgpmwrlosB5.a1:
sgpmwrlosB1.a1:
sgpmwrlosB4.a0:
sgpmwrlosB1.a0:
sgpmwrlosB5.a0:
sgpmwrlosB4.a1:
|
| Start Date | Start Time | End Date | End Time |
|---|---|---|---|
| 07/01/1996 | 2030 | 07/28/1996 | 0015 |
| Subject: | Loss of thermal stabilization |
| DataStreams: | sgpmwrlosB1.a1 |
| Description: | DQR No: Platform: sgpmwrlos, sgp5mwravg,
sgpqmemwrlos
Subject: Loss of thermal stabilization
Date Submitted:
Submitted By: JIM LILJEGREN _X_ Instrument Mentor
___ EST Member
___ Science Team Member
___ Other _____________________________
For questions or problems, please contact the ARM Experiment Center at
509-375-6898 or via email at dqr@arm.gov.
Platform/Measurement:
What level data: a0,a1,c1
What location was the data collected at: SGP B1 (Hillsboro, KS)
SGP B4 (Vici, OK)
SGP B5 (Morris, OK)
SGP B6 (Purcell, OK)
SGP C1 (Lamont, OK)
Period of time in question (see table below)
Data should be labeled:
___ questionable ___ All data fields affected
_X_ incorrect _X_ Only some data fields affected:
___ wrong calibration
___ others "23tbsky","31tbsky","vap","liq"
Discussion of Problem:
I pointed out in a previous DQR (P960405.1) that during August of 1994
and 1995 the microwave radiometers would lose thermal stabilization on
very hot, sunny days when the temperature in the radiometer enclosure
rose above the set point for thermal stabilization (~50 deg C). Although
I had planned to travel to the SGP prior to August 1996 to adjust the
set points upward to prevent this problem from occuring this year, the
temperatures in July 1996 were hotter than in previous years and the
loss of stabilization problem occurred before I could make the needed
adjustment.
The purpose of this note is the identify the time periods for which
this problem occurred. More specific information about the problem,
including how the problem is detected and its effect on the reported
values of integrated water vapor and integrated cloud liquid water are
provided in the earlier DQR.
It is useful to repeat here that when the thermal stabilization is
lost, the reported precipitable water vapor increases and the liquid
water path decreases (and becomes SIGNIFICANTLY NEGATIVE (-0.1 mm) on
clear sky days). The RMS noise level in the data also increases
sharply. THESE ANOMALOUS VALUES HAVE BEEN INCLUDED IN THE 5-MINUTE
AVERAGES.
LOCATION BEGINNING DATE AND TIME ENDING DATE AND TIME
C1 (Central Facility)
1 July 96 18:25 GMT 2 July 96 02:00 GMT
2 16:45 3 02:30
3 17:40 4 02:15
4 15:50 4 17:10
5 17:00 6 03:30
6 16:00 7 03:00
7 20:20 8 01:30
18 20:00 18 23:45
19 18:30 20 01:20
20 19:45 21 02:25
21 17:00 22 02:20
22 19:30 23 23:00
B1 (Hillsboro, KS)
1 July 96 20:30 2 July 96 01:15
2 17:00 3 02:00
17 20:30 18 00:15
18 19:25 19 02:00
19 19:00 20 02:30
20 18:35 21 00:30
21 20:20 22 01:40
28 20:55 28 00:15
B4 (Vici, OK) 2 July 96 19:25 2 July 96 23:15
3 19:35 3 21:15
4 20:40 5 00:30
5 19:15 6 02:00
6 19:00 6 22:40
7 20:45 8 00:30
21 19:45 22 02:00
B5 (Morris, OK)
1 July 96 18:35 2 July 96 00:45
2 17:20 3 01:15
3 17:25 4 02:00
5 20:20 6 01:45
6 16:45 7 02:30
7 18:10 8 01:00
19 20:00 20 00:20
20 19:30 21 00:55
21 18:15 22 01:30
22 19:30 23 01:15
23 22:00 24 00:15
B6 (Purcell, OK)
1 July 96 20:15 2 July 96 00:10
2 18:40 3 00:05
3 20:40 4 00:35
4 20:15 5 00:10
5 19:45 6 01:15
6 19:10 7 01:40
19 21:30 19 23:00
20 20:15 21 00:05
21 21:45 22 01:00
22 21:45 23 00:00
Other observations/measurements impacted by this problem:
none
Suggested Corrections of the Problem: (e.g. change calibration factor and
recompute, flag data with this comment, etc.)
Flag with this comment. |
| Measurements: | sgpmwrlosB1.a1:
|
| Start Date | Start Time | End Date | End Time |
|---|---|---|---|
| 07/02/1996 | 1925 | 07/22/1996 | 0200 |
| Subject: | Loss of thermal stabilization |
| DataStreams: | sgpmwrlosB4.a1 |
| Description: | DQR No: Platform: sgpmwrlos, sgp5mwravg,
sgpqmemwrlos
Subject: Loss of thermal stabilization
Date Submitted:
Submitted By: JIM LILJEGREN _X_ Instrument Mentor
___ EST Member
___ Science Team Member
___ Other _____________________________
For questions or problems, please contact the ARM Experiment Center at
509-375-6898 or via email at dqr@arm.gov.
Platform/Measurement:
What level data: a0,a1,c1
What location was the data collected at: SGP B1 (Hillsboro, KS)
SGP B4 (Vici, OK)
SGP B5 (Morris, OK)
SGP B6 (Purcell, OK)
SGP C1 (Lamont, OK)
Period of time in question (see table below)
Data should be labeled:
___ questionable ___ All data fields affected
_X_ incorrect _X_ Only some data fields affected:
___ wrong calibration
___ others "23tbsky","31tbsky","vap","liq"
Discussion of Problem:
I pointed out in a previous DQR (P960405.1) that during August of 1994
and 1995 the microwave radiometers would lose thermal stabilization on
very hot, sunny days when the temperature in the radiometer enclosure
rose above the set point for thermal stabilization (~50 deg C). Although
I had planned to travel to the SGP prior to August 1996 to adjust the
set points upward to prevent this problem from occuring this year, the
temperatures in July 1996 were hotter than in previous years and the
loss of stabilization problem occurred before I could make the needed
adjustment.
The purpose of this note is the identify the time periods for which
this problem occurred. More specific information about the problem,
including how the problem is detected and its effect on the reported
values of integrated water vapor and integrated cloud liquid water are
provided in the earlier DQR.
It is useful to repeat here that when the thermal stabilization is
lost, the reported precipitable water vapor increases and the liquid
water path decreases (and becomes SIGNIFICANTLY NEGATIVE (-0.1 mm) on
clear sky days). The RMS noise level in the data also increases
sharply. THESE ANOMALOUS VALUES HAVE BEEN INCLUDED IN THE 5-MINUTE
AVERAGES.
LOCATION BEGINNING DATE AND TIME ENDING DATE AND TIME
C1 (Central Facility)
1 July 96 18:25 GMT 2 July 96 02:00 GMT
2 16:45 3 02:30
3 17:40 4 02:15
4 15:50 4 17:10
5 17:00 6 03:30
6 16:00 7 03:00
7 20:20 8 01:30
18 20:00 18 23:45
19 18:30 20 01:20
20 19:45 21 02:25
21 17:00 22 02:20
22 19:30 23 23:00
B1 (Hillsboro, KS)
1 July 96 20:30 2 July 96 01:15
2 17:00 3 02:00
17 20:30 18 00:15
18 19:25 19 02:00
19 19:00 20 02:30
20 18:35 21 00:30
21 20:20 22 01:40
28 20:55 28 00:15
B4 (Vici, OK) 2 July 96 19:25 2 July 96 23:15
3 19:35 3 21:15
4 20:40 5 00:30
5 19:15 6 02:00
6 19:00 6 22:40
7 20:45 8 00:30
21 19:45 22 02:00
B5 (Morris, OK)
1 July 96 18:35 2 July 96 00:45
2 17:20 3 01:15
3 17:25 4 02:00
5 20:20 6 01:45
6 16:45 7 02:30
7 18:10 8 01:00
19 20:00 20 00:20
20 19:30 21 00:55
21 18:15 22 01:30
22 19:30 23 01:15
23 22:00 24 00:15
B6 (Purcell, OK)
1 July 96 20:15 2 July 96 00:10
2 18:40 3 00:05
3 20:40 4 00:35
4 20:15 5 00:10
5 19:45 6 01:15
6 19:10 7 01:40
19 21:30 19 23:00
20 20:15 21 00:05
21 21:45 22 01:00
22 21:45 23 00:00
Other observations/measurements impacted by this problem:
none
Suggested Corrections of the Problem: (e.g. change calibration factor and
recompute, flag data with this comment, etc.)
Flag with this comment. |
| Measurements: | sgpmwrlosB4.a1:
|
| Start Date | Start Time | End Date | End Time |
|---|---|---|---|
| 07/01/1996 | 1835 | 07/24/1996 | 0015 |
| Subject: | Loss of thermal stabilization |
| DataStreams: | sgpmwrlosB5.a1 |
| Description: | DQR No: Platform: sgpmwrlos, sgp5mwravg,
sgpqmemwrlos
Subject: Loss of thermal stabilization
Date Submitted:
Submitted By: JIM LILJEGREN _X_ Instrument Mentor
___ EST Member
___ Science Team Member
___ Other _____________________________
For questions or problems, please contact the ARM Experiment Center at
509-375-6898 or via email at dqr@arm.gov.
Platform/Measurement:
What level data: a0,a1,c1
What location was the data collected at: SGP B1 (Hillsboro, KS)
SGP B4 (Vici, OK)
SGP B5 (Morris, OK)
SGP B6 (Purcell, OK)
SGP C1 (Lamont, OK)
Period of time in question (see table below)
Data should be labeled:
___ questionable ___ All data fields affected
_X_ incorrect _X_ Only some data fields affected:
___ wrong calibration
___ others "23tbsky","31tbsky","vap","liq"
Discussion of Problem:
I pointed out in a previous DQR (P960405.1) that during August of 1994
and 1995 the microwave radiometers would lose thermal stabilization on
very hot, sunny days when the temperature in the radiometer enclosure
rose above the set point for thermal stabilization (~50 deg C). Although
I had planned to travel to the SGP prior to August 1996 to adjust the
set points upward to prevent this problem from occuring this year, the
temperatures in July 1996 were hotter than in previous years and the
loss of stabilization problem occurred before I could make the needed
adjustment.
The purpose of this note is the identify the time periods for which
this problem occurred. More specific information about the problem,
including how the problem is detected and its effect on the reported
values of integrated water vapor and integrated cloud liquid water are
provided in the earlier DQR.
It is useful to repeat here that when the thermal stabilization is
lost, the reported precipitable water vapor increases and the liquid
water path decreases (and becomes SIGNIFICANTLY NEGATIVE (-0.1 mm) on
clear sky days). The RMS noise level in the data also increases
sharply. THESE ANOMALOUS VALUES HAVE BEEN INCLUDED IN THE 5-MINUTE
AVERAGES.
LOCATION BEGINNING DATE AND TIME ENDING DATE AND TIME
C1 (Central Facility)
1 July 96 18:25 GMT 2 July 96 02:00 GMT
2 16:45 3 02:30
3 17:40 4 02:15
4 15:50 4 17:10
5 17:00 6 03:30
6 16:00 7 03:00
7 20:20 8 01:30
18 20:00 18 23:45
19 18:30 20 01:20
20 19:45 21 02:25
21 17:00 22 02:20
22 19:30 23 23:00
B1 (Hillsboro, KS)
1 July 96 20:30 2 July 96 01:15
2 17:00 3 02:00
17 20:30 18 00:15
18 19:25 19 02:00
19 19:00 20 02:30
20 18:35 21 00:30
21 20:20 22 01:40
28 20:55 28 00:15
B4 (Vici, OK) 2 July 96 19:25 2 July 96 23:15
3 19:35 3 21:15
4 20:40 5 00:30
5 19:15 6 02:00
6 19:00 6 22:40
7 20:45 8 00:30
21 19:45 22 02:00
B5 (Morris, OK)
1 July 96 18:35 2 July 96 00:45
2 17:20 3 01:15
3 17:25 4 02:00
5 20:20 6 01:45
6 16:45 7 02:30
7 18:10 8 01:00
19 20:00 20 00:20
20 19:30 21 00:55
21 18:15 22 01:30
22 19:30 23 01:15
23 22:00 24 00:15
B6 (Purcell, OK)
1 July 96 20:15 2 July 96 00:10
2 18:40 3 00:05
3 20:40 4 00:35
4 20:15 5 00:10
5 19:45 6 01:15
6 19:10 7 01:40
19 21:30 19 23:00
20 20:15 21 00:05
21 21:45 22 01:00
22 21:45 23 00:00
Other observations/measurements impacted by this problem:
none
Suggested Corrections of the Problem: (e.g. change calibration factor and
recompute, flag data with this comment, etc.)
Flag with this comment. |
| Measurements: | sgpmwrlosB5.a1:
|
| Start Date | Start Time | End Date | End Time |
|---|---|---|---|
| 08/01/1996 | 0000 | 08/31/1996 | 2359 |
| Subject: | SGP/MWR/B1/B4/B5/B6/C1 - Thermal Stabilization Adjustment |
| DataStreams: | sgp1mwravgC1.c1, sgp5mwravgB1.c1, sgp5mwravgB4.c1, sgp5mwravgB5.c1, sgp5mwravgB6.c1, sgp5mwravgC1.c1, sgpmwrlosB1.a0, sgpmwrlosB1.a1, sgpmwrlosB4.a0, sgpmwrlosB4.a1, sgpmwrlosB5.a0, sgpmwrlosB5.a1, sgpmwrlosB6.a0, sgpmwrlosB6.a1, sgpmwrlosC1.a1, sgpmwrlosC1.b1 |
| Description: | In order to correct a thermal stabilization problem identified earlier I adjusted the thermal set point of the microwave radiometers at the SGP upward from 48-50 deg C to 55 deg C in early August 1996 according to the schedule given below. B6 5 August 1996 C1 6 August 1996 B1 7 August 1996 B5 8 August 1996 Subsequent to making this adjustment the MWRs were put in TIP mode to check on whether the change in set point temperature affected their calibration. Because clear sky conditions were quite intermittent, it is difficult to determine whether the substantial variability in the tip data were attributable to the change in thermal set point. The instrument calibration was not altered in August. Tip data were again collected with these instruments in September prior to the beginning and at the close of the Water Vapor IOP. For example, the calibration of the instrument at the central facility (S/N 10) derived from the September data was essentially the same as that derived from calibration data acquired in February 1996. Although this would lead one to believe that altering the thermal set point did not affect the instrument calibration, it may be that some transient effect was induced. In comparing soundings launched from the central facility with the microwave radiometer there, I noticed that those sondes calibrated in June 1996 consistently reported lower integrated water vapor than the radiometer in July and September (during the IOP) but were in better agreement with the radiometer for the two weeks period immediately after the set point was adjusted. I suspect that adjusting the thermal set point may have temporarily increased the radiometer gain (kelvins/volt) thereby lowering the measured brightness temperature and the retrieved integrated water vapor. It is not clear why a temporary change in gain should occur or even whether it did. But users of the data should be aware that the data from the microwave radiometers at the SGP may be anomalous during August 1996. |
| Measurements: | sgpmwrlosB5.a1:
sgp5mwravgC1.c1:
sgp5mwravgB6.c1:
sgpmwrlosB4.a0:
sgpmwrlosB6.a0:
sgpmwrlosC1.b1:
sgpmwrlosB1.a0:
sgp1mwravgC1.c1:
sgpmwrlosC1.a1:
sgpmwrlosB4.a1:
sgpmwrlosB1.a1:
sgp5mwravgB1.c1:
sgp5mwravgB5.c1:
sgpmwrlosB5.a0:
sgp5mwravgB4.c1:
sgpmwrlosB6.a1:
|
| Start Date | Start Time | End Date | End Time |
|---|---|---|---|
| 12/26/1996 | 1900 | 01/02/1997 | 1800 |
| Subject: | Reprocess: Incorrect calibration installed |
| DataStreams: | sgpmwrlosB4.a0, sgpmwrlosB4.a1, sgpmwrtipB4.a0 |
| Description: | After the hard disk was replaced in the MWR computer at Vici, I mistakenly installed the calibration for the MWR at Lamont. I have corrected the error. |
| Measurements: | sgpmwrlosB4.a0:
sgpmwrtipB4.a0:
sgpmwrlosB4.a1:
|
| Start Date | Start Time | End Date | End Time |
|---|---|---|---|
| 10/27/1997 | 2000 | 11/10/1997 | 1940 |
| Subject: | Manually corrected error in header files |
| DataStreams: | sgpmwrlosB1.a0, sgpmwrlosB1.a1, sgpmwrlosB5.a0, sgpmwrlosB5.a1, sgpmwrtipB5.a0 |
| Description: | On 10/27/97 at 20:00 UTC, an error was made while remotely editing the MWR configuration file. This produced an error in the data file header which made the normal processing programs fail. The problem was identified on 11/10/97. The configuration file at BF1 was corrected on 11/11/97 at 19:40. MWR.BBF5 wasremoved from service on 11/5/97 17:54. The configuration file at BF5 was corrected prior to reinstalling the MWR on 1/9/98. The file headers of these data were reconstructed and the data were delivered to the Archive on 11/26/97 for MWR.BF1 and on 12/3/97 for MWR.BF5. This DQR is being filed to note that the headers were manually recreated. The data should be unaffected. This DQR is based on information obtained from Victor Morris and Robin Perez. |
| Measurements: | sgpmwrtipB5.a0:
sgpmwrlosB5.a1:
sgpmwrlosB1.a1:
sgpmwrlosB1.a0:
sgpmwrlosB5.a0:
|
| Start Date | Start Time | End Date | End Time |
|---|---|---|---|
| 01/09/1998 | 1757 | 02/09/1998 | 1659 |
| Subject: | SGP/MWR/B5 - Reprocess: Calibration update |
| DataStreams: | sgpmwrlosB5.a0, sgpmwrlosB5.a1, sgpmwrtipB5.a0 |
| Description: | With the MWR at Morris, there appears to be a very large (~0.5mm) positive bias in the LWP
and the PWV values are much larger (~4cm) than reported by the soundings. Recent repairs
by the manufacturer appear to have significantly changed the calibration.
The tip data acquired during the SCM IOP on 29-30 January at Morris have been reduced. It
was updated at 17:00 on 9 February. The calibration will be closely monitored to
determine if the previouly-reported (P971104.1) drift in the 31.4 GHz channel has been corrected.
The table below compares the latest calibration with previous ones.
23.8 GHz 31.4 GHz
----------------------- -----------------------
Date Location Tips Tnd(K) tc(K/K) err(K) Tnd(K) tc(K/K) err(K)
Jun 97 B5/Morris 2566 168.85 -0.071 0.33 186.15 -0.005 0.24
Aug 97 B5/Morris 1229 169.97 -0.103 0.31 188.45 -0.029 0.19
Nov 97 B5/Morris 3420 169.17 -0.082 0.24 188.76 +0.003 0.20
Jan 98 B5/Morris 2340 218.64 -0.107 0.23 219.41 +0.007 0.18
The data collected since the instrument was reinstalled on 9 January until the calibration
was updated will need to be reprocessed. |
| Measurements: | sgpmwrlosB5.a1:
sgpmwrtipB5.a0:
sgpmwrlosB5.a0:
|
| Start Date | Start Time | End Date | End Time |
|---|---|---|---|
| 01/16/1998 | 1907 | 02/10/1998 | 2359 |
| Subject: | SGP/MWR/B5 - Incorrect serial number |
| DataStreams: | sgpmwrlosB5.a0, sgpmwrlosB5.a1, sgpmwrtipB5.a0 |
| Description: | The MWR serial number was changed from 012 to 001 in the configuration file while the instrument was off line for repairs and testing. This resulted in an incorrect serial number used in the filename extension of the raw data file and placed in the header of the cdf file. Data quality were not affected. |
| Measurements: | sgpmwrtipB5.a0:
sgpmwrlosB5.a1:
sgpmwrlosB5.a0:
|
| Start Date | Start Time | End Date | End Time |
|---|---|---|---|
| 04/03/1995 | 0000 | 10/12/1998 | 1900 |
| Subject: | SGP/MWR/B1/B4/B6/C1 - software change |
| DataStreams: | sgpmwrlosB1.a0, sgpmwrlosB1.a1, sgpmwrlosB4.a0, sgpmwrlosB4.a1, sgpmwrlosB6.a0, sgpmwrlosB6.a1, sgpmwrlosC1.a1, sgpmwrlosC1.b1, sgpmwrtipB1.a0, sgpmwrtipB4.a0, sgpmwrtipB6.a0 |
| Description: | The MWR operating software was changed on 12 October 1998 to provide additional functionality as described below. This change affects the format of the raw and ingested data. 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. Editor's Note: The SGP.C1 data were reprocessed in 2004 and enhancement #3 described above was applied to the data prior to Oct 1998. The SGP.BF data are queued for reprocessing as well. |
| Measurements: | sgpmwrtipB1.a0:
sgpmwrlosB1.a1:
sgpmwrlosB4.a0:
sgpmwrlosB6.a0:
sgpmwrlosC1.b1:
sgpmwrtipB6.a0:
sgpmwrlosB1.a0:
sgpmwrtipB4.a0:
sgpmwrlosC1.a1:
sgpmwrlosB4.a1:
sgpmwrlosB6.a1:
|
| Start Date | Start Time | End Date | End Time |
|---|---|---|---|
| 02/12/1994 | 0000 | 02/10/1998 | 2359 |
| Subject: | SGP/MWR/B5 - Software Change |
| DataStreams: | sgpmwrlosB5.a1 |
| Description: | The MWR operating software was changed on 12 February 1998 to provide additional functionality as described below. This change affects the format of the raw and ingested data. 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: | sgpmwrlosB5.a1:
|
| Start Date | Start Time | End Date | End Time |
|---|---|---|---|
| 03/10/1998 | 2000 | 05/19/1998 | 0000 |
| Subject: | SGP/MWR/B1 out of calibration |
| DataStreams: | sgpmwrlosB1.a0, sgpmwrlosB1.a1 |
| Description: | A shift in the calibration of MWR/B1 occurred on 10 March 1998, apparently due to a power failure (see P980513.1). The calibration was corrected on 19 May. |
| Measurements: | sgpmwrlosB1.a1:
sgpmwrlosB1.a0:
|
| Start Date | Start Time | End Date | End Time |
|---|---|---|---|
| 07/21/1993 | 1406 | 01/12/1999 | 2359 |
| Subject: | SGP/MWR/B1/B4/B5/B6/C1 - software upgrade (version 3.27) |
| DataStreams: | sgpmwrlosB1.a1, sgpmwrlosB4.a1, sgpmwrlosB5.a1, sgpmwrlosB6.a1, sgpmwrlosC1.a1, sgpmwrlosC1.b1, sgpmwrtipB1.a0, sgpmwrtipB4.a0, sgpmwrtipB5.a0, sgpmwrtipB6.a0 |
| Description: | At 00:00 GMT on 7 January version 3.27 of the MWR operating program was installed and made operational at the SGP central facility (C1). No problems were noted over the next few days and the boundary facility MWRs (B1, B4, B5, B6) were upgraded at 20:00 GMT on 11 January. This version includes a beam width correction I developed as well as providing the capability to automatically level the elevation mirror (that is, to automatically detect and correct offsets in the elevation angle stepper motor position.) On 12 January I discovered that the '486-based MWR computers at B1, B4 and B6 were not executing the system command to move and rename the data files so that the ARM data system could retrieve them. Reducing the length of the storage arrays in the auto-leveling feature from 1000 to 250 resolved the problem. This results in the auto-leveling being based on only 4 hours of clear sky data rather than 16 hours at B5 and C1. This version of the program is 3.28. Version 3.27 (running at B5 and C1) can be installed if and when these computers are upgraded to Pentium-class machines. The improvement in the quality of the tip curves resulting from the auto-leveling has been dramatic: differences in the brightness temperatures at 3 airmasses (19.5 and 160.5 degrees) have been reduced from +/- 5 K to +/- 0.5 K. The goodness-of-fit coefficient for the tip curves has improved from about 0.995 to over 0.998. In order to take full advantage of this improvement to detect and reject cloudy tip curves, the minimum value of the goodness-of-fit coefficient for a valid tip curve has been increased from 0.995 to 0.998. Editor's Note: The SGP.C1 data were reprocessed in 2004 to produce a common DOD for all time. The 1996-1998 data reprocessing included beam width and mirror-leveling corrections, but the data prior to that range did not have these corrections applied. |
| Measurements: | sgpmwrtipB1.a0:
sgpmwrlosB5.a1:
sgpmwrtipB5.a0:
sgpmwrlosB1.a1:
sgpmwrlosC1.b1:
sgpmwrtipB6.a0:
sgpmwrtipB4.a0:
sgpmwrlosC1.a1:
sgpmwrlosB4.a1:
sgpmwrlosB6.a1:
|
| Start Date | Start Time | End Date | End Time |
|---|---|---|---|
| 10/12/1998 | 1900 | 10/28/1998 | 1228 |
| Subject: | SGP/MWR/B1/B4/B6 - Reprocess: Data Ingest Problem |
| DataStreams: | sgpmwrlosB1.a0, sgpmwrlosB1.a1, sgpmwrlosB4.a0, sgpmwrlosB4.a1, sgpmwrlosB6.a0, sgpmwrlosB6.a1 |
| Description: | The first version of the new ingest produced incorrect values of variables tbsky23 and ir_temp and global attribute elevation_angle. In evaluating this file, I found that tbsky23 is actually tnd31, ir_temp is noise_injection_temp_31, and elevation is '1079410688 deg' instead of 90. All other variables and global attributes are ok. Note, the SGP.C1 data were also originally affected by this problem, but they were subsequently reprocessed. This DQR will be removed when the SGP.BF data have also been reprocessed. |
| Measurements: | sgpmwrlosB1.a1:
sgpmwrlosB6.a0:
sgpmwrlosB4.a0:
sgpmwrlosB1.a0:
sgpmwrlosB4.a1:
sgpmwrlosB6.a1:
|
| Start Date | Start Time | End Date | End Time |
|---|---|---|---|
| 10/29/1998 | 0000 | 08/12/1999 | 2359 |
| Subject: | SGP/MWR/B1/B4/B5/B6 - data file split at 23:59 |
| DataStreams: | sgpmwrlosB1.a1, sgpmwrlosB1.b1, sgpmwrlosB4.a1, sgpmwrlosB4.b1, sgpmwrlosB5.a1, sgpmwrlosB5.b1, sgpmwrlosB6.a1, sgpmwrlosB6.b1, sgpmwrtipB1.a1, sgpmwrtipB4.a1, sgpmwrtipB5.a1, sgpmwrtipB6.a1 |
| Description: | A problem with the MWR operating software has been corrected. However, several files were generated that contain one record of data collected at midnight but labeled with the previous day's date. |
| Measurements: | sgpmwrlosB5.a1:
sgpmwrlosB1.a1:
sgpmwrtipB6.a1:
sgpmwrlosB6.b1:
sgpmwrlosB4.b1:
sgpmwrtipB4.a1:
sgpmwrtipB5.a1:
sgpmwrlosB1.b1:
sgpmwrtipB1.a1:
sgpmwrlosB4.a1:
sgpmwrlosB5.b1:
sgpmwrlosB6.a1:
|
| Start Date | Start Time | End Date | End Time |
|---|---|---|---|
| 03/05/1999 | 0000 | 06/08/1999 | 1710 |
| Subject: | SGP/MWR/B4 - power lines in field of view |
| DataStreams: | sgp5mwravgB4.c1, sgpmwrlosB4.00, sgpmwrlosB4.a1, sgpmwrlosB4.b1, sgpmwrtipB4.00, sgpmwrtipB4.a1 |
| Description: | On 5 March 1999, the local power company installed transmission lines north of BF4 at an elevation angle of about 30 degrees from the MWR, in the field of view of tip scans. This affected the calibration of the instrument and the retrieved values of precipitable water vapor and liquid water path. On 8 June 1999 at 1710 GMT, the MWR was remotely rotated 90 degrees so the instrument would scan from east to west. This reorientation has corrected the problem. |
| Measurements: | sgpmwrlosB4.00:
sgpmwrtipB4.00:
sgpmwrlosB4.b1:
sgpmwrtipB4.a1:
sgp5mwravgB4.c1:
sgpmwrlosB4.a1:
|