MODAPS PCR VNP 25-003
| PCR Number | VNP 25-003 |
|---|---|
| Date | 2025-03-27 |
| Initiator | Carol Davidson on behalf of Maoshen Zhao |
| Abstract | PGE536 2.0.5, PGE617 2.0.3, PGE657 2.0.5 Initial version of NPP/GPP and EvapoTrans products, both gap-filled and non-gap-filled, suite of PGEs, PGE536 and PGE617. This processing also makes use of PGE657 for gap-filled processing stream. PGE657 creates the year-end gap-filled LAI/FPAR used as input to the gap-filled processing streams. All of these PGEs were developed at SCF followed by suitable loader moduel (LM) and production rule updates and additions by Land SIPS SSTG to complete the transition to Land SIPS PGEs. Reprocessing using the Gap-Filled versions of PGE617 and PGE536 was done using PGE617 2.0.2 and PGE536 2.0.4. In running these versions the Ops and SSTG teams found that the PGE LoaderModules needed minor revisions so that rather than going to error when LAI/FPAR or LandCover inputs are not staged, they go to TryAgainLater and print a warning message. This update was made prior to putting PGE617 and PGE536 into use for non-gap-filled processing. Therefore, PGE617 v2.0.3 and PGE536 v2.0.5 are what is in use for those versions and will be used in future runs of the gap-filled versions. |
| Problem Statement | Introduction of the JPSS1 and SNPP Gap-Filled and non-Gap-Filled VIIRS NPP/GPP and EvapoTrans 8-day and yearly products as part of the VIIRS Collection 2 (C2) and onwards. Specifically, this suite will include the SNP and JPSS versions of 8-day and yearly VNP16A2/A3, VNP16A2GF/A3GF, VJ116A2/A3, VJ116A2GF/A3GF, VNP17A2/A3, andVNP17A2GF/A3GF. Suite of PGEs to support this includes PGE657, the VNP/VJ115A2HGF, year-end gap-filled LAI/FPAR. As with MODIS variations, the gap-filled are used for reprocessing and the non-gap-filled for forward processing. |
| Description of Change | Initial version of NPP/GPP and EvapoTrans products, both gap-filled and non-gap-filled, suite of PGEs, PGE536 and PGE617. This processing also makes use of PGE657 for gap-filled processing stream. PGE657 creates the year-end gap-filled LAI/FPAR used as input to the gap-filled processing streams. All of these PGEs were developed at SCF followed by suitable loader moduel (LM) and production rule updates and additions by Land SIPS SSTG to complete the transition to Land SIPS PGEs. Reprocessing using the Gap-Filled versions of PGE617 and PGE536 was done using PGE617 2.0.2 and PGE536 2.0.4. In running these versions the Ops and SSTG teams found that the PGE LoaderModules needed minor revisions so that rather than going to error when LAI/FPAR or LandCover inputs are not staged, they go to TryAgainLater and print a warning message. This update was made prior to putting PGE617 and PGE536 into use for non-gap-filled processing. Therefore, PGE617 v2.0.3 and PGE536 v2.0.5 are what is in use for those versions and will be used in future runs of the gap-filled versions. |
| Products Affected | VNP16A2/A3,VNP16A2GF/A3GF,VJ116A2/A3,VJ116A2GF/A3GF,VNP17A2/A3,VNP17A2GF/A3GF |
| Software Affected | PGE536 2.0.5, PGE617 2.0.3, PGE657 2.0.5 |
| Processing String to Receive the Change | J1 Forward Processing. J1 Reprocessing. |
| Downstream Product Effects | VIIRS SNPP and JPSS1 Land products, including the VNP/VJ116A2/3, VNP/VJ116A2/A3GF, VNP/VJ117A2/3, and VNP/VJ117A2/3GF |
| Data Granules to be Used for Science Testing | Several science tests have been carried out, to assess the performance of these products. All results have been duly reviewed and confirmed by the science team and LDOPE, before final approval. |
| Justification | The introduction of the SNPP and JPSS1 VIIRS GPP and ET products will ensure the continuity with the MODIS heritage products and will provide critical datasets that are requested by the user and the modeling community. |
| Effective Date for Implementation of Change | PGE617 2.0.2 and PGE536 2.0.4 were put into use for gap-filled mission reprocessing on 12/20/24 for processing SNPP 2012001 to 2025001 and JPSS1 2018001 to 2025001. PGE617 2.0.3 and PGE536 2.0.5 were put into use for the non-gap-filled processing starting on 3/5/25 for SNPP and JPSS1 data starting from 1/1/25. |
| Status | Major algorithm development completed. Maoshen Zhao approved 3/27/2025. Sadashiva Devadiga approved 4/2/2025. Sudipta Sarkar implemented 3/31/2025. |
