MODAPS PCR VNP 23-001

PCR Number VNP 23-001
Date 2023-01-18
Initiator George Riggs, support by Carol Davidson
Abstract PGE507 2.0.6

Revision to the L2 Snow, PGE507, to disable the SWI screen because it was blocking too much snow cover. A BasicQA value is set for the SWI screen. Change developed by George Riggs after review of C2 datasets. Change to L2 Snow influences downstream gridded snow and snow CMG.

Problem Statement The VIIRS C2 L2 Snow, PGE507, with SWI screening enabled was blocking too much snow.
Description of Change Revision to the L2 Snow, PGE507, to disable the SWI screen because it was blocking too much snow cover. A BasicQA value is set for the SWI screen. Change developed by George Riggs after review of C2 datasets. Change to L2 Snow influences downstream gridded snow and snow CMG.
Products Affected VNP10, VNP10C, VJ110, VJ110C
Software Affected PGE507 2.0.6
Processing String to Receive the Change S-NPP Forward Processing. S-NPP Reprocessing. J1 Forward Processing. J1 Reprocessing.
Downstream Product Effects SNPP & JPSS1 VIIRS Land products, including: VNP10A1, VNP10A1F, VNP10C1, VJ110A1, VJ110A1F, VJ110C1 (products listed are those export to NSIDC; reprocessing of snow also includes L2G and L2G Light Snow datasets as well).
Data Granules to be Used for Science Testing Science test has been carried out in AS4011 and processed L2 Snow through downstream Snow Products. All results have been duly reviewed and confirmed by the science team and LDOPE, before final approval.
Justification Revising the L2 Snow will allow for more accurate detection of snow cover.
Effective Date for Implementation of Change PGEs noted in this document are expected to go into production, as part of the C2 reprocessing the week of January 16, 2023. See attached reprocessing plans for details on start use dates and periods to be reprocessed with update in place.
Status Major algorithm development completed. George Riggs approved 01/18/2023. Sadashiva Devadiga approved 01/18/2023. Sudipta Sarkar approved 01/18/2023.