| DQR ID | Subject | Data Streams Affected | Data Quality Metric |
|---|---|---|---|
| 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 |
| D140221.8 | SGP/RL/C1 - Reprocessing Notice (RID 1026) | sgprlprofmerge1turnC1.c0 | Does not affect quality |
| D140326.7 | SGP/RLPROF/C1 - Reduced signal due to partially closed laser shutter | sgprlprofmerge1turnC1.c0 | Suspect |
| D140416.3 | SGP/RLPROF/C1 - Reduced SNR due to partial laser blockage | sgprlprofmerge1turnC1.c0 | Suspect |
| D140619.4 | SGP/RLPROF/C1 - Invalid data due to hatch closure | sgprlprofmerge1turnC1.c0 | Incorrect |
| 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:
|
| Start Date | Start Time | End Date | End Time | Data Quality Metric |
|---|---|---|---|---|
| 05/03/2012 | 0000 | 01/28/2014 | 0000 | Does not affect quality |
| Subject: | SGP/RL/C1 - Reprocessing Notice (RID 1026) |
| DataStreams: | sgprlprofmerge1turnC1.c0 |
| Description: | See below for details of reprocessing that was completed on 20140822. Original DQR category:3 (Yellow, Suspect ). ----------------------------------------------------------- Regions where photon counting rates exceed 20 MHz are 37.5 meters too high. Correct data by shifting down 37.5 meters. Additional information: The detection system in the RL uses Licel data recorders. These recorders provide simultaneous measurements of analog voltage and photon counts from the photo multiplier tubes. The analog signal has an inherent delay relative to the photon counting signal, which is corrected for in the rlprofmerge VAP. The delay parameter is determined through offline analysis by the instrument mentor, and then inputted into a configuration file that is used by the VAP. During the effected period, the delay parameter for the narrow-field-of-view elastic channel was incorrect. As a result, the analog signal leads the photon counting signal by 5 range bins (5X7.5m = 37.5m). Photon counting rates that are outputted by the rlprofmerge VAP use the analog signals in regions where the photon counting rates exceed 20 MHz. So the counting rate data in these regions are (incorrectly) shifted downward by 37.5 m (i.e. -37.5m). |
| Measurements: | sgprlprofmerge1turnC1.c0:
|
| Start Date | Start Time | End Date | End Time | Data Quality Metric |
|---|---|---|---|---|
| 03/25/2014 | 1500 | 03/26/2014 | 1220 | Suspect |
| Subject: | SGP/RLPROF/C1 - Reduced signal due to partially closed laser shutter |
| DataStreams: | sgprlprofmerge1turnC1.c0 |
| Description: | The laser shutter was partially closed during the period in question. This resulted in a reduction in the sensitivity of all detection channels. |
| Measurements: | sgprlprofmerge1turnC1.c0:
|
| Start Date | Start Time | End Date | End Time | Data Quality Metric |
|---|---|---|---|---|
| 03/25/2014 | 1500 | 03/26/2014 | 1215 | Suspect |
| Subject: | SGP/RLPROF/C1 - Reduced SNR due to partial laser blockage |
| DataStreams: | sgprlprofmerge1turnC1.c0 |
| Description: | The laser output was partially blocked. This resulted in reduced SNR in all detection channels. |
| Measurements: | sgprlprofmerge1turnC1.c0:
|
| Start Date | Start Time | End Date | End Time | Data Quality Metric |
|---|---|---|---|---|
| 06/18/2014 | 1910 | 06/19/2014 | 2145 | Incorrect |
| Subject: | SGP/RLPROF/C1 - Invalid data due to hatch closure |
| DataStreams: | sgprlprofmerge1turnC1.c0 |
| Description: | The outgoing beam was completely blocked by the hatch. As a result, the data contain no valid atmospheric signals. |
| Measurements: | sgprlprofmerge1turnC1.c0:
|