MODAPS PCR 16-007
| PCR Number | 16-007 |
|---|---|
| Date | 2016-02-26 |
| Initiator | Zhengming Wan |
| Abstract | PGE16 v6.4.14. Change the input snow sds name to 'NDSI_Snow_Cover' from 'Fractional_Snow_Cover'. Convert the input NDSI snow cover to fractional snow using the equation frac_snow = -0.01 + 1.45 * ndsi_snow for ndsi_snow in the range (0, 100). |
| Problem Statement | Operational C6 LST code designed to work with the fractional snow cover in the input L2 Snow Product, MOD10_L2, which has been replaced by the "NDSI Snow Cover" in the operational C6 version of the snow product. |
| Description of Change | Update the C6 LST algorithm to read in the "NDSI Snow Cover" from the input C6 Snow product and convert to fractional snow using the regression equation recommended by the snow science team. |
| Products Affected | MxD11_L2, MxD11A1, MxD11B1 |
| Software Affected | MOD_PR16 |
| Processing String to Receive the Change | Terra and Aqua Reprocessing, NRT |
| Downstream Product Effects | None. |
| Data Granules to be Used for Science Testing | To verify the change on NRT, ran science test generating LST globally for data day 2016046 on the NRT system using the C6 Snow and C52 snow as input. Ran science test of the same version of LST PGE on MODAPS by processing LST for data day 2011113 and 2011114.2010-059 |
| Justification | LST generated without this change would be largely incorrect over snow covered areas since the PGE won't have been able to use the snow information from the C6 product. Through science test run at MODAPS, LDOPE has verified that with this change in place in the C6 LST algorithm, the LST produced using the C6 snow is identical to the LST produced using the current operational LST PGE with C52 snow as input. This ensures the temporal consistency of LST records within the C6 collection though using different versions of snow as inputs over the period of C6 reprocessing. No reprocessing of LST is required when C6 snow is reprocessed. This version of PGE16 is to be used in conjunction with the C6 Snow Cover. |
| Effective Date for Implementation of Change | Completed. |
| Status | Major algorithm development completed. Sadashiva Devadiga approved on 02/29/2016. Michael King approved on 03/22/2016. Gang Ye approved on 03/23/2016. |
