| DQR ID | Subject | Data Streams Affected |
|---|---|---|
| D030922.3 | NSA/MPL/C1 - laser head failure | nsamplC1.00, nsamplC1.a1, nsamplcmask1clothC1.c1, nsamplsmask1clothC1.c1 |
| D040426.3 | NSA/MPL/C1 - Hardware Failure/Missing Data | nsamplC1.00, nsamplC1.a1, nsamplcmask1clothC1.c1, nsamplsmask1clothC1.c1 |
| D050215.5 | NSA/MPL/C1 - MPL clock drift | nsamplC1.a1, nsamplpsC1.a0 |
| Start Date | Start Time | End Date | End Time |
|---|---|---|---|
| 04/28/2002 | 0200 | 08/29/2002 | 0100 |
| Subject: | NSA/MPL/C1 - laser head failure |
| DataStreams: | nsamplC1.00, nsamplC1.a1, nsamplcmask1clothC1.c1, nsamplsmask1clothC1.c1 |
| Description: | On 2002-04-28 the laser energy was observed to decrease throughout the day. Although low clouds continued to be detected, by the end of the day the output laser energy was about 10% of nomimal. This decrease continued throughout 2002-04-29 to the extent that clouds were no longer detected. The source of failure was eventually determined to be the laser head, requiring the MPL to be shipped for repair. The MPL was reinstalled on 2002-08-28 at about 01:00 UTC. MPL NSA data from 2002-04-29 through 2002-08-27 (inclusive) should not be used. |
| Measurements: | nsamplC1.a1:
nsamplsmask1clothC1.c1:
nsamplcmask1clothC1.c1:
nsamplC1.00:
|
| Start Date | Start Time | End Date | End Time |
|---|---|---|---|
| 11/21/2003 | 0500 | 12/01/2003 | 1441 |
| Subject: | NSA/MPL/C1 - Hardware Failure/Missing Data |
| DataStreams: | nsamplC1.00, nsamplC1.a1, nsamplcmask1clothC1.c1, nsamplsmask1clothC1.c1 |
| Description: | Data are missing during this extended period due to a hardware failure. |
| Measurements: | nsamplC1.a1:
nsamplsmask1clothC1.c1:
nsamplcmask1clothC1.c1:
nsamplC1.00:
|
| Start Date | Start Time | End Date | End Time |
|---|---|---|---|
| 11/11/2003 | 0000 | 02/05/2004 | 0000 |
| Subject: | NSA/MPL/C1 - MPL clock drift |
| DataStreams: | nsamplC1.a1, nsamplpsC1.a0 |
| Description: | The MPL PC clock was noted to be off (slow) by more than an hour over a several day period. It has previously been noted that the time synchronization program "D-4" fails to update the PC clock under certain circumstances. As a result, the program "D-4" was replaced by "AboutTime" on 2/5/2004. The specifics of this problem are not well understood. It turns out that the instrument has TWO clocks on the instrument computer display - one being displayed by the MPL software and the other being the PC clock displayed in the lower right-hand corner of the screen. The MPL software clock was the one that is noted on daily rounds and was never off by any amount. Apparently the only clock that was off was the computer clock. What is clear is that between the time the MPL computer was installed on 11-11-2003 and the CM log on 1-06-2004 the MPL clock exhibited a discrepancy of over 1 hour and 20 minutes. What is not clear is whether this clock discrepancy was also applied to the data time stamps. Furthermore, seven days later the MPL clock exhibited only a 1.77 second drift. Not exceptional at all, and not in line with the previous discrepancy of more than 4800 seconds over a span of 57 days. Attempts to identify gradual correctible clock drift in the MPL data were not successful. As a worst-case scenario, the MPL data may be inappropriately time-stamped by as much a 1 hour 20 minutes and 41 seconds slow relative to UTC between the dates of 2003-11-11 and 2004-01-06. After this time until 2004-02-05 time synchronization was maintained within a few seconds a day with local observer assistance. |
| Measurements: | nsamplC1.a1:
nsamplpsC1.a0:
|