MODAPS PCR 20-018
| PCR Number | 20-018 |
|---|---|
| Date | 2020-08-12 |
| Initiator | Jim Ray |
| Abstract | PGE199 1.0.7 -- This is the first MODAPS version of the PGE for AVHRR. |
| Problem Statement | Need a PGE to generate the Long Term Data Record (LTDR) at MODAPS by processing the data acquired by the AVHRR on-board the MetOp-B. The product will conform to the NASA ESDIS file format and metadata requirement to facilitate archive and distribution of these records from NASA LAADS DAAC. Prior to this effort the LTDR records were being generated at the SCF by processing the AVHRR data acquired on-board the NOAA series of satellites. |
| Description of Change | 1. Derive the MODAPS PGE from the SCF process to generate similar records with changes needed to meet the MODAPS processing environment and configuration, product file format and metadata requirements. 2. General changes to the offline code to support processing at MODAPS as a PGE, including: a. Changes to present product metadata compliant with MODAPS/LAADS CMR requirements. b. Introduce MODIS ODL style metadata. c. Ability to read inputs from PCF. d. Change file names/ESDTs to be MODAPS processing compliant. e. Log errors using the MODAPS/SDPToolkit message passing APIs. f. Changes to handle ephemeris as static ancillary file instead of dynamic files, based on an established AVHRR database at MODAPS. g. Updated thermal channel coefficients. h. Limit ancillary weather inputs to MCD09ANC and GDAS. 3. Specific changes implemented to support processing of AVHRR instrument on-board the MetOp-B processing: a. Use of Lat/Lon internal to the AVHRR data files for geolocation, instead of ephemeris files. b. Use of updated calibration coefficients, based on cross-calibration of MetOp-B with N19. c. Introduce flexibility in RHO3 calculation for MetOp-B, based upon the inputs. |
| Products Affected | AVHRR Version 5 LTDR products. |
| Software Affected | PGE199 1.0.7 |
| Processing String to Receive the Change | NOAA-N* Reprocessing. MetOp-B Reprocessing. MetOp-B Forward Processing. MetOp-C Reprocessing. MetOp-B Forward Processing. |
| Downstream Product Effects | None |
| Data Granules to be Used for Science Testing | Two major science tests were carried out in AS 1741 and AS1767 to assess the overall operational readiness of PGE199 at MODAPS, confirm all metadata and assess the calibration and performance of AVHRR onboard MetOp-B with respect to the same from the NOAA-19 platform. |
| Justification | Enable the transition of the AVHRR LTDR processing from offline processing at SCF to MODAPS to generated the LTDR records from AVHRR on board the MetOp-B |
| Effective Date for Implementation of Change | This version of PGE199 is to be used to generate LTDR records in the forward processing by processing AVHRR data on from MetOp-B inputs. Later, with approval from the PI, the same PGE could be used to process the records from the beginning of the MetOp-B mission. On-going processing of the LTDR records on ltdr cluster from processing of AVHRR on N19 will be continued until NCDC has upgraded their system to use the VIIRS or MetOP based LTDR data in place of the current N19 LTDR records. Added by Sadashiva on 8/20/20 6:31pm. |
| Status | Major algorithm development completed. Sadashiva Devadiga approved on 08/19/2020. Gang Ye approved on 08/20/2020. |
