DQR ID | Subject | Data Streams Affected |
---|---|---|
D070717.1 | SGP/RL/C1 - Invalid liquid water channel data | sgprlC1.a0 |
D090122.2 | SGP/RL/C1 - Invalid mode 0 data | sgprlC1.a0, sgprlprofmerge1turnC1.c0 |
Start Date | Start Time | End Date | End Time |
---|---|---|---|
09/06/2006 | 1920 | 03/05/2008 | 0000 |
Subject: | SGP/RL/C1 - Invalid liquid water channel data |
DataStreams: | sgprlC1.a0 |
Description: | On 20060906, the liquid water channel (LWC) was disabled due to the removal of its photomultiplier tube (PMT). Consequently, the signals recorded for the LWC contain either zero or pure noise after that date. Also, starting on 20070522, the LWC was populated with data from the T2 channel as a result of a slight reconfiguration of the data acquisition system. On 4 March 2008 The LW channel photomultiplier tube was reinstalled in the Raman lidar. Effective 0000 UTC on 5 March 2008 the LW channel began producing valid liquid water data once again. |
Measurements: | sgprlC1.a0:
|
Start Date | Start Time | End Date | End Time |
---|---|---|---|
11/12/2008 | 0000 | 01/13/2009 | 0000 |
Subject: | SGP/RL/C1 - Invalid mode 0 data |
DataStreams: | sgprlC1.a0, sgprlprofmerge1turnC1.c0 |
Description: | On 20081112 the filter wheel for the wide field-of-view (WFOV) channel was incorrectly rotated. The net effect was that we were recording neutral density filter data when we should have been collecting data with the channels completely blocked (mode 0 data). As a result, the WFOV mode 0 data contains contributions from the pulse return and the solar background that should not be present. The mode 0 data is used in the rlprof_merge VAP to remove the electronic background level from the analog signal. After the problem was identified the filter wheel was set back to its proper rotation on 20090112. A work-around has been implemented in the rlprof_merge VAP to handle the lack of valid mode 0 during the affected period. The work-around involves computing the electronic background from pre-pulse data during nighttime periods only. With this technique we are not able to estimate the range-dependence of the electronic backgound, as we did before. However, this range dependence is typically quite weak, and so the impact on the rlprof_merge output is expected to be minimal. |
Measurements: | sgprlprofmerge1turnC1.c0:
sgprlC1.a0:
|