MODAPS PCR VNP 25-005
| PCR Number | VNP 25-005 |
|---|---|
| Date | 2025-04-09 |
| Initiator | Carol Davidson |
| Abstract | PGE609 2.0.5 Revised the PGE609_LoaderModule.pl so that they use a realtime delay, currently set to 36 hours in the MODAPS Config table. If the preferred GEOSIT inputs with StartTime +/- 12 hours from the granule start time have not arrived before the timeout is reached, then the LoaderModules will go to using +/-24 hours from the granule start time. If this is still not sufficient, the LoaderModules now allow for the recipe instances to be forced and then the LoaderModule will use +/- 36 hours from granule start time for the GEOSIT inputs. Note that the PGE609Timeout in the Config table can have the period adjusted if desired. If the entry should be missing for any reason, PGE609 will default to a real time delay of 24 hours. |
| Problem Statement | The Swath L2 LST PGE for NRT, VIIRS PGE609, did not have their LoaderModules configured to be able to use older GEOSIT inputs in cases where current GEOSIT inputs were missing. This caused use to have gaps in both datasets when we had a period where the GEOSIT data was delayed in arriving. |
| Description of Change | Revised the PGE609_LoaderModule.pl so that they use a realtime delay, currently set to 36 hours in the MODAPS Config table. If the preferred GEOSIT inputs with StartTime +/- 12 hours from the granule start time have not arrived before the timeout is reached, then the LoaderModules will go to using +/-24 hours from the granule start time. If this is still not sufficient, the LoaderModules now allow for the recipe instances to be forced and then the LoaderModule will use +/- 36 hours from granule start time for the GEOSIT inputs. Note that the PGE609Timeout in the Config table can have the period adjusted if desired. If the entry should be missing for any reason, PGE609 will default to a real time delay of 24 hours. |
| Products Affected | VNP21IMG_NRT, VJ121IMG_NRT |
| Software Affected | PGE609 2.0.5 |
| Processing String to Receive the Change | NRT |
| Downstream Product Effects | VIIRS L2 Swath LST for NRT only |
| Data Granules to be Used for Science Testing | A science test was conducted of PGE609 2.0.5-1 on nrt4 in AS91. The test was setup on 3/31/25 using data day 3/25/25 for the processing day. We then gradually added in the GEOSIT inputs that would meet the +/- 24 hour requirement for early in the day granules and confirmed they were locating the proper GEOSIT. Then we attemped to force the later granules and confirmed they were locating/staging GEOSIT using the +/-36 hour period. This confirmed that the PGEs will now locate inputs and process rather than having data gaps in cases where the preferred GEOSIT are not available in a timely manner. |
| Justification | After experiencing a GEOSIT data delay and needing to force the NRT L2 LST, it was discovered that PGE609 did not allow for alternative GEOSIT inputs to be staged. However, similar L2 LST PGEs do, and it was decided we should allow for this approach in PGE609 as well. |
| Effective Date for Implementation of Change | PGE609 2.0.5 went into use in NRT3 and NRT4 on 4/3/25 |
| Status | Internal PCR. Sudipta Sarkar implemented 04/09/2025. |
