MODAPS PCR VNP 24-018
| PCR Number | VNP 24-018 |
|---|---|
| Date | 2024-12-09 |
| Initiator | Carol Davidson |
| Abstract | PGE555 2.0.5 Initially, new version was with metadata fixes, similar to those for PGE554, PGE556 and PGE557 (see PCRs 24-016 and 24-017) and added support for NRT processing. Then Z. Wang submitted an update to address a bug found that was causing large blocky areas with fill values in the VNP46A2_nrt browse image over ocean. The value of MOD44W for these large fill values is 253 which is No Data Value while code was using value "1" for water. Z. Wang updated the code in main.c line 203-204 to fix this issue. |
| Problem Statement | C2 Daily gridded LBAN was flagged for needing fixes to metadata, but was also found to need some corrections for deep water tiles. Additionally, the PGE, and suite of upstream PGEs whose outputs are used by PGE555, were updated to process in NRT system. The correction would go into place in the leading edge for the land tiles and for reprocessing all water tiles in C2. The new version would be in use at the leading edge for all tiles in NRT. |
| Description of Change | Initially, new version was with metadata fixes, similar to those for PGE554, PGE556 and PGE557 (see PCRs 24-016 and 24-017) and added support for NRT processing. Then Z. Wang submitted an update to address a bug found that was causing large blocky areas with fill values in the VNP46A2_nrt browse image over ocean. The value of MOD44W for these large fill values is 253 which is No Data Value while code was using value "1" for water. Z. Wang updated the code in main.c line 203-204 to fix this issue. |
| Products Affected | VNP46A2, VJ146A2, VNP46A2_NRT, VJ146A2_NRT |
| Software Affected | PGE555 2.0.5 |
| Processing String to Receive the Change | S-NPP Forward Processing. S-NPP Reprocessing. J1 Foward Processing. J1 Reprocessing. NRT |
| Downstream Product Effects | All VIIRS land products. |
| Data Granules to be Used for Science Testing | A science test was conducted of PGE555 2.0.5-0 and results reviewed by LDOPE and the LBAN science team. |
| Justification | Correction requested by LDOPE after review of data found the discrepancies for assorted dataset attributes. |
| Effective Date for Implementation of Change | PGE555 2.0.5 was installed on 12/9/24 to nrt and C2 processing/reprocessing streams. This new version will be used from 12/10/24 onward in NRT. The new version will be used to reprocess all water tiles processed to date in C2 for both SNPP and JPSS1. The new version will be used for land tiles starting at the leading edge of C2, which would be 12/10/2024, and also 7/1/2018 for SNPP data and 7/1/2019 for JPSS1 data in C2. |
| Status | Major algorithm development completed. Sadashiva Devadiga approved 12/12/2024. Sudipta Sakar implemented 12/04/2024. |
