DQR ID | Subject | Data Streams Affected |
---|---|---|
D090507.2 | GRW/VCEIL/M1 - Receiver failure | grwvceil25kM1.b1 |
D090522.1 | GRW/MWR/M1 - Loose mirror | grwmwrlosM1.b1, grwmwrtipM1.a1 |
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 |
---|---|---|---|
05/01/2009 | 0000 | 06/16/2009 | 0745 |
Subject: | GRW/MWR/M1 - Loose mirror |
DataStreams: | grwmwrlosM1.b1, grwmwrtipM1.a1 |
Description: | The data from the MWR were suspicious and became progressively worse. The problem was traced back to the fact that the screw that keeps the mirror in place had become loose and the mirror was freely rotating. The mirror was tightened on 6/9/2009, however the measurements were noisy until 6/16, when the instrument was rebooted and all the connections checked. Measurements between 5/1 and 6/9 should not be used. Data between 6/9 and 6/16 are usable, although they are very noisy. |
Measurements: | grwmwrlosM1.b1:
grwmwrtipM1.a1:
|