MODAPS PCR 25-003
| PCR Number | 25-003 |
|---|---|
| Date | 2025-04-10 |
| Initiator | Carol Davidson |
| Abstract | PGE116 6.1.13 Revised the MODIS PGE116's PGE116N_LoaderModule.pl so that it uses 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 PGE116NTimeout in the Config table can have the period adjusted if desired. If this entry should be missing for any reason, PGE116N will default to a real time delay of 24 hours. |
| Problem Statement | The Swath L2 LST MODIS PGE116, specifically PGE116N for NRT, did not have their LoaderModules configured to be able to use older GEOSIT inputs in cases where current GEOSIT inputs were missing. This caused us to have gaps in both datasets when we had a period where the GEOSIT data was delayed in arriving. |
| Description of Change | Revised the MODIS PGE116's PGE116N_LoaderModule.pl so that it uses 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 PGE116NTimeout in the Config table can have the period adjusted if desired. If this entry should be missing for any reason, PGE116N will default to a real time delay of 24 hours. |
| Products Affected | MOD21, MYD21 |
| Software Affected | PGE116 6.1.13 |
| Processing String to Receive the Change | Terra Forward Processing. Aqua Forward Processing. NRT |
| Downstream Product Effects | MODIS LST for NRT only |
| Data Granules to be Used for Science Testing | Process two global days of Aqua and Terra on the MODAPS test system using the C61 L1B as input. |
| Justification | A science test was conducted of PGE116N 6.1.13-1 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. |
| Effective Date for Implementation of Change | PGE116N 6.1.13 went into use in NRT3 and NRT4 on 4/3/25 |
| Status | Internal PCR. Sudipta Sarkar implemented on 04/09/2025. |
