MODAPS PCR 16-009
| PCR Number | 16-009 |
|---|---|
| Date | 2016-04-05 |
| Initiator | Amit Angal |
| Abstract | PGE02 v5.0.48 LUTs -- Fixes the sector rotation anomaly before/after the lunar maneuver. PGE02 v6.0.20 LUTs -- Fixed the sector rotation anomaly before/after the lunar maneuver. |
| Problem Statement | Terra spacecraft autonomously transitioned into Earth Point Safe-Hold on 2016/049/14:33:17 triggered by an Inclination Adjust Maneuver (IAM) #43, and MODIS entered into Safe Mode at 049/14:33:30. On day 2016/055 MODIS was successfully switched back to Science Mode. Gain changes have been observed in most MODIS bands after the recovery. A look-up-table (LUT) update is necessary to account for the change. |
| Description of Change | The Reflective Solar bands (RSB) are monitored by using the Solar Diffuser (SD)/Solar Diffuser Stability Monitor (SDSM) calibration. A Blackbody Warmup/Cooldown event was scheduled after the recovery of MODIS to track the gain changes for Thermal Emissivity bands (TEB). Other than the gain change, a significant change in the behavior of detector response is also observed for some TEB. Detectors 9 and 10 in band 27 and detectors 6 and 9 in band 30 become noisy. Detector 8 in band 30 is inoperable. The following is the summary of all LUT update due to this safe mode, RSB LUT update: m1_table; TEB LUT update: a0_table, a2_table, band_21_b1_table; QA LUT update: detector_quality_flag_values_table. Since MODIS focal plane temperatures have stabilized since day 2016/059, the first time stamp used in the above updated LUT is 2016059 00:00:00. This can be used as a reference for the start time of MODIS product. The LUT version is V6.1.20.14 for collection 6 and V5.0.48.14 for collection 5. Both of them have been delivered to MODAPS in March 2016. MCST has started the forward LUT update since then. |
| Products Affected | All Terra MODIS product including both collections 5 and 6. |
| Software Affected | PGE02 v5.0.48, PGE02 v6.1.20 |
| Processing String to Receive the Change | Terra Forward, Terra Reprocessing |
| Downstream Product Effects | All MODIS product. |
| Data Granules to be Used for Science Testing | Atmos and Land teams have performed their tests, and are reviewing and evaluating their results. |
| Justification | MCST has validated the test results. All the changes are expected. |
| Effective Date for Implementation of Change | Actual Changes Implemented: Terra MODIS L1B LUT V6.1.20.14 for collection 6 and V5.0.48.14 for Collection 5. |
| Status | Major algorithm development completed. Jack Xiong approved 04/05/2016; Steve Platnick approved 04/06/2016; Sadashiva Devadiga approved 04/06/2016; Gang Ye approved on 04/06/2016. |
