| DQR ID | Subject | Data Streams Affected | Data Quality Metric |
|---|---|---|---|
| D090122.2 | SGP/RL/C1 - Invalid mode 0 data | sgprlprofmerge1turnC1.c0 | Incorrect |
| D110409.1 | SGP/RL/C1 - Incorrect time array | sgprlprofmerge1turnC1.c0 | Incorrect |
| D110720.1 | SGP/RL/C1 - Malfunction in WFOV data acquisition | sgprlprofmerge1turnC1.c0 | Incorrect |
| D111004.1 | SGP/RL/C1 - Frequent intermittent drop-outs in the WFOV photon counting signals | sgprlprofmerge1turnC1.c0 | Incorrect |
| D111004.3 | SGP/RL/C1 - Bad shot count data | sgprlprofmerge1turnC1.c0 | Incorrect |
| Start Date | Start Time | End Date | End Time | Data Quality Metric |
|---|---|---|---|---|
| 11/12/2008 | 0000 | 01/13/2009 | 0000 | Incorrect |
| Subject: | SGP/RL/C1 - Invalid mode 0 data |
| DataStreams: | 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:
|
| Start Date | Start Time | End Date | End Time | Data Quality Metric |
|---|---|---|---|---|
| 03/27/2011 | 0100 | 03/29/2011 | 1300 | Incorrect |
| Subject: | SGP/RL/C1 - Incorrect time array |
| DataStreams: | sgprlprofmerge1turnC1.c0 |
| Description: | On March 27 2011 at 0100 GMT the Raman lidar's instrument computer automatically advanced it's time by one hour (transition to daylight savings time). The problem was eventually fixed on March 29 2011 at 1300 when the clock was set back one hour to the correct time. The ingest experienced problems when the clock was set back one hour. The time arrays in the following files are set one hour ahead of what they should be: 1. sgprlC1.a0.20110327.000001.cdf for profile indices equal to or greater than 355 2. all of sgprlC1.a0.20110327.120001.cdf 3. all of sgprlC1.a0.20110328.134549.cdf 4. all of sgprlC1.a0.20110329.000005.cdf 5. sgprlC1.a0.20110329.120005.cdf for profile indices less than or equal to 72 Also, the time arrays in sgprlC1.a0.20110329.120005.cdf between profile indices 73 through 641 are incorrect. In this case, the offset varies approximately linearly with profile index from 1 hour at index 73 to 0 at index 641. The ingest apparently introduced some unphysical variations in time in this part of the file. |
| Measurements: | sgprlprofmerge1turnC1.c0:
|
| Start Date | Start Time | End Date | End Time | Data Quality Metric |
|---|---|---|---|---|
| 05/31/2011 | 1400 | 08/23/2011 | 2011 | Incorrect |
| Subject: | SGP/RL/C1 - Malfunction in WFOV data acquisition |
| DataStreams: | sgprlprofmerge1turnC1.c0 |
| Description: | A malfunction in the data acquisition hardware resulted in corrupted data in the wide-field-of-view (WFOV) nitrogen, water vapor and elastic channels. The problem is so serious as to yield these signals useless during the period covered by this DQR. Do not use any data products derived from the WFOV raw signals during the period covered by this DQR. This includes water vapor mixing ratio, aerosol scattering ratio, and aerosol extinction. The narrow-field-of-view (NFOV)channels are unaffected by this problem. So data products derived from only the NFOV channel should be okay. These include the 'high' channel signals from the merge VAP, depolarization and temperature. |
| Measurements: | sgprlprofmerge1turnC1.c0:
|
| Start Date | Start Time | End Date | End Time | Data Quality Metric |
|---|---|---|---|---|
| 05/31/2011 | 1330 | 08/19/2011 | 1900 | Incorrect |
| Subject: | SGP/RL/C1 - Frequent intermittent drop-outs in the WFOV photon counting signals |
| DataStreams: | sgprlprofmerge1turnC1.c0 |
| Description: | Beginning suddenly, near 1330 UTC on 31 May 2011, the liquid water and all three WFOV channels began showing intermittent and frequent drop-outs in the photon counting signals. These drop-outs were periods when the signal would momentarily fade and then come back. This problem, which was traced to a malfunction of the Licel data recorders, occurred at irregular intervals and with such frequency as to render the data from the affected channels useless. This problem persisted until repairs were made to the Licel transient recorders on 19 August 2011. Although only the WFOV channels (and liquid water channel) were affected, the aerosol and water vapor mixing ratio VAPs are computed by combining NFOV and WFOV channels. Thus, all of these higher level data products were adversely impacted by the drop-out problem. The NFOV data in the sgprlC1.a0 and sgprlprofmerge1turnC1.c0 datastreams were unaffected by the "drop-out" problem. These signals could be used to compute aerosol optical properties and water vapor mixing ratio. |
| Measurements: | sgprlprofmerge1turnC1.c0:
|
| Start Date | Start Time | End Date | End Time | Data Quality Metric |
|---|---|---|---|---|
| 09/29/2011 | 0000 | 10/06/2011 | 1500 | Incorrect |
| 07/15/2011 | 1000 | 07/15/2011 | 1400 | Incorrect |
| 05/03/2012 | 1430 | 06/12/2012 | 1930 | Incorrect |
| 08/08/2011 | 1300 | 09/15/2011 | 0000 | Incorrect |
| Subject: | SGP/RL/C1 - Bad shot count data |
| DataStreams: | sgprlprofmerge1turnC1.c0 |
| Description: | The number of laser pulses averaged per profile, or shot count, exhibited erratic behavior during the periods in question. The values reported in the sgprlC1.a0 datastream were incorrect and varied radically from profile to profile. Shot counts are used in the Merge VAP to compute photon count rates, which are then used by all the other RL VAPs. Thus, the shot count problem renders all of the RL VAPs bad or suspect during the periods in question. It appears that the problem was caused as the signal on the line between two triggering units got noisier over time, causing the second unit to occasionally trigger on noise. The second unit triggers the Licel electronics. So the false triggering on the second unit caused false shot count readings. On 6 October 2011 the trigger level was adjusted by the on-site technician, and this solved the problem. On 3 May 2012 the DG535 pulse generator, which is used to trigger the Licel data recorders, was swapped out with a spare. After installation of the spare, the system started recording erroneous values of shot counts. The problem was fixed on 12 June 2012 when the on-site tech increased trigger level on the DG535. |
| Measurements: | sgprlprofmerge1turnC1.c0:
|