| DQR ID | Subject | Data Streams Affected |
|---|---|---|
| D090507.2 | GRW/VCEIL/M1 - Receiver failure | grwvceil25kM1.b1 |
| D100216.6 | GRW/VCEIL/M1 - Reprocess: Incorrect serial_number and sum_backscatter fields | grwvceil25kM1.b1 |
| D100222.1 | GRW/WACR/M1 - Interference/False signal | grwwacrM1.b1, grwwacrspeccmaskxpolM1.a0, grwwacrspeccmaskcopolM1.a0 |
| D100402.3 | GRW/WACR/M1 - Coherence Filter Contamination | grwwacrM1.b1 |
| D101007.2 | GRW/WACR/M1 - Missing data | grwwacrM1.b1 |
| Start Date | Start Time | End Date | End Time |
|---|---|---|---|
| 04/22/2009 | 0925 | 05/16/2009 | 1010 |
| Subject: | GRW/VCEIL/M1 - Receiver failure |
| DataStreams: | grwvceil25kM1.b1 |
| Description: | The AMF VCEIL had lower-than-normal laser transmitter power, ~84%, so the instrument was replaced with a spare on 4/22. The spare VCEIL had just been repaired but began to display receiver failure warnings. Diagnostic information was sent to Vaisala and we discussed either replacing the receiver with the one from the original VCEIL (with the degraded transmitter) or replacing the transmitter in the original VCEIL with the one from the spare. Vaisala recommended the latter because the original VCEIL is a much newer unit. On 5/16, the site operator replaced the transmitter in the original VCEIL with the one from the spare, realigned the optics, recalibrated the laser, and put the instrument back into service, successfully correcting the problem. The data during this period were intermittently incorrect, containing warning flags and alarms and unreasonable cloud base heights. |
| Measurements: | grwvceil25kM1.b1:
|
| Start Date | Start Time | End Date | End Time |
|---|---|---|---|
| 04/13/2009 | 0000 | 10/31/2009 | 2359 |
| Subject: | GRW/VCEIL/M1 - Reprocess: Incorrect serial_number and sum_backscatter fields |
| DataStreams: | grwvceil25kM1.b1 |
| Description: | Attribute serial_number: In most cases, this field is not representative of the actual serial number of the instrument because the value did not change when an instrument changed locations or was replaced with a spare. Variable sum_backscatter: An out-of-range condition for the "sum of detected and normalized backscatter" was reported as 0 instead of missing (-9999). The valid range is 0 - 0.0999 /srad. |
| Measurements: | grwvceil25kM1.b1:
|
| Start Date | Start Time | End Date | End Time |
|---|---|---|---|
| 09/25/2009 | 0945 | 10/03/2009 | 1200 |
| Subject: | GRW/WACR/M1 - Interference/False signal |
| DataStreams: | grwwacrM1.b1, grwwacrspeccmaskxpolM1.a0, grwwacrspeccmaskcopolM1.a0 |
| Description: | Interference occurred between the WACR/SWACR beginning 9:45 GMT on 09/25. This effect was not as noticeable on DQ plots until ~10 GMT on 09/27 at which time the interference was quite pronounced as vertical bands in the reflectivity and velocity plots. The interference was slightly noticeable in the spectral width plots as well. Interference resulted from the SWACR using the same frequency as the WACR. Interference was alleviated by changing the pulse repetition frequency (prf) from 10 kHz to 9.9 kHz. Some minor contamination still existed during the presence of highly reflective clouds/precipitation. The Doppler velocity was not affected as much by the interference. A cloud mask based on the Doppler velocity will remove most of this contamination in the reflectivity and spectra width measurements. |
| Measurements: | grwwacrspeccmaskcopolM1.a0:
grwwacrM1.b1:
grwwacrspeccmaskxpolM1.a0:
|
| Start Date | Start Time | End Date | End Time |
|---|---|---|---|
| 06/09/2009 | 1600 | 04/02/2010 | 1200 |
| Subject: | GRW/WACR/M1 - Coherence Filter Contamination |
| DataStreams: | grwwacrM1.b1 |
| Description: | The coherence filter (software) that was added to the WACR under BCR-01500 was causing occasional contamination to WACR data. This was exhibited in the first 2000 m of range by streaking in the data over a period of time. It didn't occur often and when it did, it is quite obvious looking at the plots. On 4/2/2010 at 12:00 UTC, the coherence filter was modified to preclude working on signals with a SNR greater than 60 dB. The vendor thinks this will solve the problem. |
| Measurements: | grwwacrM1.b1:
|
| Start Date | Start Time | End Date | End Time |
|---|---|---|---|
| 09/01/2010 | 2100 | 09/24/2010 | 1930 |
| Subject: | GRW/WACR/M1 - Missing data |
| DataStreams: | grwwacrM1.b1 |
| Description: | Data are missing and unrecoverable. |
| Measurements: | grwwacrM1.b1:
|