PDS_VERSION_ID = PDS3 RECORD_TYPE = STREAM OBJECT = TEXT PUBLICATION_DATE = 2021-09-20 NOTE = "This file describes the timing issue and the offset application." END_OBJECT = TEXT END Timing error and offset application Owing to flight software issues, there can be a variable amount of error in the reporting of the image start time (typically on the order of a few tens of milliseconds in the worst case). This can be significant when map-projecting or georeferencing images. When feasible, we attempt to reduce this error by measuring the predicted position of the 1-bar limb with its actual position in image pixels for the first framelet that contains the planet. An offset of N pixels corresponds to a timing error of N/311.2 seconds at the nominal spin rate of the spacecraft. The start time of the image is then updated appropriately, so that subsequent software processing does not need to be aware of the offset. For reference, the EDR_TIMING_OFFSETS.TXT and RDR_TIMING_OFFSETS.TXT files in this directory are provided for images which were processed in this manner. It is recognized that factors such as departure of the planet's shape from the IAU spheroid and the optical depth of the limb leave residual errors, even after this process has been applied. If the offset in the last column is a floating point value other than 0.0, then an offset was applied to the image. If the value is 0.0, then an offset was not needed for the image. If the value is NULL, then an offset was not able to be determined (e.g. curvature too steep, limb apex in shadow). Timing offsets were applied to both RGB and Methane images in a given Perijove swath. Note: single band visible spectrum images are not included in this list. The specific start and end times for each Perijove swath can be found below. PJ01: 2016-240T11:58:35.370 - 2016-240T13:58:39.158 PJ02: Safe mode, no images acquired PJ03: 2016-346T15:45:47.276 - 2016-346T18:17:25.134 PJ04: 2017-033T12:09:17.802 - 2017-033T14:07:53.403 PJ05: 2017-086T07:30:52.604 - 2017-086T10:41:15.757 PJ06: 2017-139T04:46:46.264 - 2017-139T07:55:59.859 PJ07: 2017-192T01:10:57.169 - 2017-192T03:09:58.750 PJ08: 2017-244T21:05:44.006 - 2017-244T23:06:10.446 PJ09: 2017-297T16:52:46.760 - 2017-297T19:27:00.381 PJ10: 2017-350T16:39:11.911 - 2017-350T20:28:32.500 PJ11: 2018-038T12:52:23.038 - 2018-038T16:37:44.562 PJ12: 2018-091T08:09:49.991 - 2018-091T11:46:58.421 PJ13: 2018-144T03:50:43.588 - 2018-144T07:54:36.383 PJ14: 2018-197T03:32:45.150 - 2018-197T07:19:05.316 PJ15: 2018-249T23:27:00.273 - 2018-250T03:11:18.938 PJ16: 2018-302T20:09:58.360 - 2018-302T22:40:46.648 PJ17: 2018-355T16:09:23.706 - 2018-355T18:50:34.390 PJ18: 2019-043T15:50:06.034 - 2019-043T19:32:41.868 PJ19: 2019-096T13:05:48.190 - 2019-096T14:45:58.975 PJ20: 2019-149T07:29:47.963 - 2019-149T10:34:16.821 PJ21: 2019-202T03:21:56.717 - 2019-202T06:41:39.829 PJ22: 2019-255T03:02:54.739 - 2019-255T06:21:56.748 PJ23: 2019-307T21:38:13.324 - 2019-308T00:17:43.458 PJ24: 2019-360T16:56:56.782 - 2019-360T19:59:15.760 PJ25: 2020-048T17:09:05.460 - 2020-048T20:23:21.536 PJ26: 2020-101T13:12:40.790 - 2020-101T15:48:30.033 PJ27: 2020-154T09:42:01.255 - 2020-154T12:33:06.341 PJ28: 2020-207T05:34:49.621 - 2020-207T08:29:44.985 PJ29: 2020-260T01:29:57.861 - 2020-260T04:23:59.071 PJ30: 2020-313T01:13:12.715 - 2020-313T04:04:28.760 PJ31: 2020-365T21:05:51.647 - 2020-366T00:14:57.629 PJ32: 2021-052T17:01:48.065 - 2021-052T20:09:55.657 PJ33: 2021-105T22:33:08.651 - 2021-106T01:59:19.131 PJ34: 2021-159T06:46:52.489 - 2021-159T10:17:19.322 PJ35: 2021-202T06:49:58.436 - 2021-202T10:35:31.910 PJ36: 2021-245T21:19:55.474 - 2021-246T01:27:06.970 PJ37: 2021-289T16:25:33.275 - 2021-289T19:51:32.635 PJ38: 2021-333T13:29:48.032 - 2021-333T16:46:16.591