MODAPS PCR 07-012
| PCR Number | 07-012 |
|---|---|
| Date | 2007-07-16 |
| Initiator | Jim Ray |
| Abstract | Fix atmospheric QA flag, initialize QA flag for IDS, and ensure sqrt() doesn't get a negative number. |
| Problem Statement | Product generated from earlier version contained artifacts resulting from attempt to compute square root of negative numbers, incorrect flagging ofatmospheric correction flag, and uninitialized QA flag for IDS products. |
| Description of Change | Changes in this version will ensure that sqrt() doesn't get a negative number, will set the atmospheric correction flag correctly to 'NO' when no geolocation is available, and will initialize the State QA for IDS files. |
| Products Affected | L2 Land Surface Reflectance (MOD09) |
| Software Affected | PGE11 |
| Processing String to Receive the Change | Terra Forward, Terra Reprocessing, Aqua Forward, Aqua Reprocessing |
| Downstream Product Effects | L3 Daily Land Surface Reflectance CMG (MOD09CMG). Though most downstream products use the L2 MOD09, changes addressed in this version are not expected to result in any difference in the retrieved surface reflectance. |
| Data Granules to be Used for Science Testing | 1-day global test of PGE11 using data day 2007-113. Run PGE75 using the output of PGE11. |
| Justification | Above changes are necessary to remove the artifacts resulting from theunpredicated behavior of some of the libraries on invalid arguments/values.Fixing the Atmospheric QA flag will prevent the downstream algorithm fromusing the bad observations. |
| Effective Date for Implementation of Change | |
| Status | PI approved. Sadashiva Devadiga approved for Land, Vincent Salomonsom approved on 07/23/2007 |
