MODAPS PCR 15-015
| PCR Number | 15-015 |
|---|---|
| Date | 2015-04-28 |
| Initiator | Brian Wenny |
| Abstract | PGE02 v6.1.20 (Terra); v6.1.35 (Aqua). The telemetry point 'SET_FR_ENC_DELTA', instead of 'CS_FR_ENC_DELTA', is used in the L1B code to determine scans that are sector rotated. Fixes the sector rotation anomaly before/after the lunar maneuver. The change has been applied to both Aqua and Terra MODIS. |
| Problem Statement | A false multi-scan swath wide 'fire' is noticed from the fire product for the period right after the 2014345 lunar activity. MCST traced this to the internal timing/update frequency of the telemetry flag used by the L1B code to determine the sector rotation position of a scan. The result being a scan of sector rotated data that can be considered 'valid' by the L1B code which contaminates the calibration of the 20 subsequent scans (TEB uses a 40 scan average for the b1 calibration). |
| Description of Change | MCST analysis indicates the ‘SET_FR_ENC_DELTA’ telemetry correlates with the sector rotation encoder position. This issue can be corrected if this telemetry point is used by the L1B code to determine scans that are sector rotated. |
| Products Affected | L1B 1KM product for both Terra and Aqua MODIS including both collections 5 and 6. |
| Software Affected | PGE02 v6.1.20 (Terra) PGE02 6.1.35 (Aqua) |
| Processing String to Receive the Change | Terra and Aqua Forward Processing |
| Downstream Product Effects | All products use MODIS Thermal Emissive Bands. |
| Data Granules to be Used for Science Testing | Data Granules to be used for Science Testing:2005-324 and 2014-345 for Terra and 2008-343 for Aqua in AS1284.Atmos and Land teams review the test data and verified the changes. |
| Justification | MCST has validated the test results. All the changes are expected. |
| Effective Date for Implementation of Change | TBD |
| Status | Michael King approved on 05/08/2015. |
