MODAPS PCR 19-006
| PCR Number | 19-006 |
|---|---|
| Date | 2019-03-22 |
| Initiator | Dongdong Wang |
| Abstract | PGE141 v6.0.11 -- Correct the scaling of the TOA reflectance, Correct to use the back up climatology coefficient files. |
| Problem Statement | Downward surface radiation and PAR values retrieved by the prior operational science algorithm were found to be underestimated. |
| Description of Change | The source of the problem was traced to error in scaling of the TOA reflectance. Code change implemented to correctly account for the scaling by the cosine of the solar zenith angle. Other minor correction include change to optionally use the climatology coefficient files in binary and hdf format. |
| Products Affected | MCD18A1, MCD18A2 - filename and metadata only |
| Software Affected | PGE141 v6.0.11 |
| Processing String to Receive the Change | Terra and Aqua Forward Processing. Terra and Aqua Forward Reprocessing. |
| Downstream Product Effects | None |
| Data Granules to be Used for Science Testing | Science test run generating global product for an 8-day period. |
| Justification | The daily radiation and PAR values were underestimated by the prior version of the algorithm, to large extent at higher latitude. |
| Effective Date for Implementation of Change | Completed |
| Status | Major algorithm development completed. Sadashiva Devadiga approved 03/22/2019. Gang Ye approved on 03/22/2019. |
