MODAPS PCR VNP 22-006
| PCR Number | VNP 22-006 |
|---|---|
| Date | 2022-10-20 |
| Initiator | Sudipta Sarkar, Carol Davidson, Dongdong |
| Abstract | PGE635 2.0.7, PGE641 2.0.8, PGE642 2.0.2 Initial version of the PGE641/642 was developed at SCF in Univ. Of Maryland, followed by suitable loader module (LM) and production rule updates and additions by LandSIPS STIG to complete the transition to a LandSIPS PGE. The upstream L1B gridding process (PGE635) was developed by STIG along the lines of its MODIS equivalent. Specific Algorithm Change/Improvements, following the initial delivery:
|
| Problem Statement | Introduction of the SNPP VIIRS version of the global Downward Shortwave Radiation (DSR) and Photosynthetically Active Radiation (PAR) products, as part of the VIIRS Collection 2 (C2) and onwards. Specifically, this suite will include the SNPP versions of the tiled VNP18A1/A2 and the CMG VNP18C1/C2 products and the JPSS1 versions of the tiled VJ118A1/A2 and the CMG VJ118C1/C2 products. |
| Description of Change | Initial version of the PGE641/642 was developed at SCF in Univ. Of Maryland, followed by suitable loader module (LM) and production rule updates and additions by LandSIPS STIG to complete the transition to a LandSIPS PGE. The upstream L1B gridding process (PGE635) was developed by STIG along the lines of its MODIS equivalent. Specific Algorithm Change/Improvements, following the initial delivery:
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| Products Affected | VNP18A1, VNP18A2, VNP18C1, VNP18C2, VJ118A1, VJ118A2, VJ118C1, and VJ118C2 |
| Software Affected | PGE635 2.0.7, PGE641 2.0.8, PGE642 2.0.2 |
| Processing String to Receive the Change | S-NPP Forward Processing. S-NPP Reprocessing. J1 Forward Processing. J1 Reprocessing. |
| Downstream Product Effects | SNPP VIIRS Land products, including VNP18A1/A1/C1/C2. |
| Data Granules to be Used for Science Testing | Several science tests have been carried out, including one final one in AS 3397, to assess the performance of these products, including the effect of the VIIRS L1B cross-calibration. All results have been duly reviewed and confirmed by the science team and LDOPE, before final approval |
| Justification | The introduction of the SNPP VIIRS DSR/PAR 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 | PGEs noted in this document are expected to go into production, as part of the C2 reprocessing by the week of October 24, 2022 for SNPP, and JPSS1 the week of January 17, 2023. |
| Status | Major algorithm development completed. Sadashiva Devadiga approved 10/26/2022. Sudipta Sarkar approved 10/20/2022. |
