MODAPS PCR 15-025
| PCR Number | 15-025 |
|---|---|
| Date | 2015-06-25 |
| Initiator | James Kuyper |
| Abstract | PGE96 v6.0.3. Ensure that the first generated orbit always covers the nominal start time of a granule, even if a new orbit starts between that time and the time of the first data packet. |
| Problem Statement | Bugs 2823, 2826, and 4824 were resolved by the delivery of PGE96 6.0.0, delivered 2013-06-10, which changed the start and end time metadata to match the run start and end time, rather than the timestamps of the first and last packets of data. The SDP Toolkit's ephemeris routines require that the orbital metadata cover the start time for the file. The current version of PGE96 only generates orbits to cover the timestamps of the contained packets. As a result, in the unlikely case that an orbit starts during the small time interval between the granule start time and the first packet time, the generated orbits will not cover the granule start time, and PGE01 will fail. This should come up about once every 600 orbits or so, and has actually been observed several times (Bugs 5682, 5720, 5735, and 5793). |
| Description of Change | Change the routines generating orbital metadata to include orbits covering the start time. |
| Products Affected | None. |
| Software Affected | PGE96 v6.0.3 |
| Processing String to Receive the Change | Aqua Forward Processing |
| Downstream Product Effects | None. |
| Data Granules to be Used for Science Testing | |
| Justification | Slight increase in the number of granules successfully generated. |
| Effective Date for Implementation of Change | Completed. |
| Status | Gang Ye approved 06/29/2015. |
