MODAPS PCR 22-010
| PCR Number | 22-010 |
|---|---|
| Date | 2021-07-27 |
| Initiator | Sudipta Sarkar on behalf of MCST |
| Abstract | PGE02 6.2.3 (Aqua) Implemented the cross-talk correction algorithm to PV LWIR and MWIR bands, (including the correction to edge frames and the uncertainty penalty due to the crosstalk correction). |
| Problem Statement | After the March 2022 Aqua safe mode event, noticeable cross-talk changes were observed in the Aqua MODIS PV LWIR bands (27, 28, 29, and 30). The cross-talk coefficients trending for the PV LWIR bands show significant increase after safe mode. |
| Description of Change | To alleviate this increased cross-talk, data from two lunar roll maneuvers (May and June 2022) have been processed since the safe mode event, and the cross-talk coefficients were derived from these lunar data. The coefficients from all detectors for each sending band were averaged to increase the efficiency. This cross-talk correction will be applied to bands 27, 28, 29 and 30 from forward production and the affected data since safe-mode event will also need to be reprocessed. |
| Products Affected | C61 Aqua MODIS L1B - Calibrated Radiance and Reflectance |
| Software Affected | PGE02 6.2.3 (Aqua) |
| Processing String to Receive the Change | Aqua Forward Processing. Aqua Reprocessing. NRT. |
| Downstream Product Effects | All C61 Aqua MODIS L2, L3 dailies and n-days. |
| Data Granules to be Used for Science Testing | A science test will be conducted prior to reprocessing. However, given the urgency of the matter and the instructions from MCST, the code change and revised LUTs were placed for C61 forward processing without any testing. Unit test was used to verify that this version could reproduce the test granule provided by MCST. |
| Justification | Code changes and accompanying Aqua L1B LUT updates became necessary, following the discovery of increased cross-talk impacts on the PV LWIR bands, after the last Aqua safe-mode event on March 2022. |
| Effective Date for Implementation of Change | The PGE02Aqua V6.2.3 has been inducted for C61 forward processing, starting 2022/208 (07/27/22). A reprocessing schedule will be decided on, based on the results of a science test and feedback from the science teams. |
| Status | Major algorithm development completed. Amit Angal approved 07/28/22. Steve Platnick approved 08/01/2022. Sadashiva Devadiga approved 08/01/2022. Sudipta Sarkar approved 08/01/2022. |
