MODAPS PCR 11-003
| PCR Number | 11-003 |
|---|---|
| Date | 2011-01-13 |
| Initiator | Jim Ray |
| Abstract | To correct PGE21 bug in all level-3 products (MOD09A1, MOD09A1C and MOD09Q1). |
| Problem Statement | 250 m data with fill values, which had QA indicating bad L1B, had nonetheless been put into the final MOD09Q1 eight-day composite (e. g., file MOD09Q1.A2003193.h08v05.005.2010340231227.hdf). |
| Description of Change | Additional checks of the QA data of the daily inputs was implemented. More specifically, both the 500 m QAs and each of the four corresponding 250m QA values are checked. |
| Products Affected | MOD_PR09A.exe and all of its Level 3 products (MOD09A1, MOD09A1C and MOD09Q1). |
| Software Affected | PGE21 v5.0.11 |
| Processing String to Receive the Change | Terra Forward, Aqua Forward |
| Downstream Product Effects | All 8-day land surface reflectance products (MOD09A1, MOD09A1C and MOD09Q1) may potentially be affected. In MOD09Q1 files, pixels flagged as having faulty L1B will be replaced by pixels from different days; and this replacement (one day for another) will also affect the 500m and coarse resolution products. However this is typically a very small number of pixels: in the example given above (file MOD09Q1 for 2003, day 193, tile h08v05), less than 0.005% of the pixels were replaced. |
| Data Granules to be Used for Science Testing | A global test for day 2010337.2010-059. |
| Justification | This change fixes an obvious bug in the code. |
| Effective Date for Implementation of Change | Completed. |
| Status | Science test completed; results evaluated by LDOPE and Science Team. Sadashiva Devadiga approved for Land, Michael King approved on 01/18/2011. |
