PDS_VERSION_ID = PDS3 RECORD_TYPE = STREAM INSTRUMENT_NAME = "RADIO SCIENCE SUBSYSTEM" TARGET_NAME = MARS DATA_SET_ID = "MGS-M-RSS-1-EXT-V1.0" PRODUCT_TYPE = AGK MISSION_NAME = "MARS GLOBAL SURVEYOR" INSTRUMENT_HOST_NAME = "MARS GLOBAL SURVEYOR" ORIGINAL_PRODUCT_ID = "mgs_hga_ext4.bc" PRODUCT_ID = "1262345A.AGK" FILE_NAME = "1262345A.AGK" START_TIME = 2001-09-19T00:00:22.848Z STOP_TIME = 2001-12-11T23:59:53.786Z PRODUCT_CREATION_TIME = 2002-01-11T00:00:00 PRODUCER_ID = NAIF ^DESCRIPTION = "TK_FTP.TXT" NOTE = " MGS HGA Gimbals CK File for Extended Mission, Mapping Cycles 34-36 =========================================================================== Created by Boris Semenov, NAIF/JPL, January 11, 2002 Orientation Data in the File -------------------------------------------------------- This file contains orientation and angular rate data for the Mars Global Surveyor (MGS) High Gain Antenna (HGA) Elevation and Azimuth gimbal frames. The orientation of the 'MGS_HGA_EL_GIMBAL' is given with respect to the 'MGS_HGA_HINGE' frame; orientation of the 'MGS_HGA_AZ_GIMBAL' is given with respect to the 'MGS_HGA_EL_GIMBAL' frame. Status -------------------------------------------------------- This file was created by merging daily HGA Gimbal CK files produced by the NAIF, JPL. No timing or any other correction was applied to the original data during merge process. Pedigree -------------------------------------------------------- The original CK files used to create this file were officially delivered to the MGS SPICE Server by NAIF, JPL. These files contained orientation of the HGA gimbal frames. The orientation was computed on the ground from the HGA gimbal angles extracted from the spacecraft engineering telemetry. HGA gimbal angle data sampling rate was once every 32 seconds. The individual daily files were merged together to provide complete coverage on a mission phase basis. A table containing the complete list of original CK files from which data were included in this file is provided at the end of these comments. Approximate Time Coverage -------------------------------------------------------- This file covers the 34th, 35th, and 36th 28-day mapping cycles of the Extended phase of the mission: COVERAGE BEGIN TIME (UTC): 2001-SEP-19 00:00:22.847 COVERAGE END TIME (UTC): 2001-DEC-11 23:59:53.786 This file is a type 3 CK file which provides linear interpolation between orientation data points extracted from telemetry. Such interpolation is not applied to the whole coverage of the file but only inside intervals where enough gimbal telemetry data was available and data points were close to each other in time for such interpolation to make sense. Given that nominal gimbal telemetry rate was once every 32 seconds the duration of the longest interval over which the data may be interpolated was set to 300 seconds, i.e. interpolation was enabled only over an eight point drop-out. For all requests for the data falling between two adjacent data points separated by more than 300 seconds the SPICELIB CK readers will return a logical flag stating 'POINTING NOT FOUND'. Tables containing the complete list of valid interpolation intervals for the AZ and EL frame data in the file are provided at the end of these comments. Since AZ and EL gimbal values were extracted from telemetry by two subsequent Telemetry Data System queries, returned sets of points for them, and thus resulting coverage intervals, may be different. Note Regarding Orientation -------------------------------------------------------- The orientation of the 'MGS_HGA_EL_GIMBAL' is given with respect to the 'MGS_HGA_HINGE' frame and was computed from the gimbal geometry and telemetered gimbal angles as follows: -- the ``MGS_HGA_HINGE'' (-94070) frame was rotated by -85 degrees about +Z axis to align its axes of the with axes of the ``MGS_HGA_EL_GIMBAL'' (-94071) frame in EL=0 position -- then rotation by the EL angle about +Z axis was applied. The orientation of the 'MGS_HGA_AZ_GIMBAL' is given with respect to the 'MGS_HGA_EL_GIMBAL' frame and was computed from the gimbal geometry and telemetered gimbal angles as follows: -- the ``MGS_HGA_EL_GIMBAL'' (-94071) frame was rotated first by +90 degrees about +Y and then by +180 degrees about +Z axis to align its axes with the axes of the ``MGS_HGA_AZ_GIMBAL'' (-94072) frame in AZ=0 positions; -- then rotation by AZ angle about +Z axis was applied. Note Regarding Angular Rates -------------------------------------------------------- Since MGS s/c engineering telemetry doesn't contain angular rate data for the gimbals, the angular rates stored in this file were computed from the orientation information. The angular rate for each orientation point was computed as average of two rates -- constant angular rate that would rotate from previous point to that point and constant angular rate that would rotate from that point to the next point. Because angular rates stored in two adjacent points in most cases are not the same, and CK readers lineraly interpolate between them, the output angular rates in general are almost never constant between any two adjacent data points stored in the file. Usage Note -------------------------------------------------------- In order to use this file an MGS SCLK file containing coefficients mapping MGS on-board time to ET and frame definitions for the MGS spacecraft and HGA hinge and gimbal frames must be loaded into a user's program. Related Kernels -------------------------------------------------------- This file was created with LSK file naif0007.tls and MGS SCLK file MGS_SCLKSCET.00040.tsc. Contacts -------------------------------------------------------- If you have any question regarding this data contact NAIF at JPL: Charles H. Acton, Jr (818)-354-3869 chuck.acton@jpl.nasa.gov Boris V. Semenov (818)-354-8136 boris.semenov@jpl.nasa.gov Appendix 1: List of the original CK files -------------------------------------------------------- mgs_hga_ck_2001-09-19.bc mgs_hga_ck_2001-09-20.bc mgs_hga_ck_2001-09-21.bc mgs_hga_ck_2001-09-22.bc mgs_hga_ck_2001-09-23.bc mgs_hga_ck_2001-09-24.bc mgs_hga_ck_2001-09-25.bc mgs_hga_ck_2001-09-26.bc mgs_hga_ck_2001-09-27.bc mgs_hga_ck_2001-09-28.bc mgs_hga_ck_2001-09-29.bc mgs_hga_ck_2001-09-30.bc mgs_hga_ck_2001-10-01.bc mgs_hga_ck_2001-10-02.bc mgs_hga_ck_2001-10-03.bc mgs_hga_ck_2001-10-04.bc mgs_hga_ck_2001-10-05.bc mgs_hga_ck_2001-10-06.bc mgs_hga_ck_2001-10-07.bc mgs_hga_ck_2001-10-08.bc mgs_hga_ck_2001-10-09.bc mgs_hga_ck_2001-10-10.bc mgs_hga_ck_2001-10-11.bc mgs_hga_ck_2001-10-12.bc mgs_hga_ck_2001-10-13.bc mgs_hga_ck_2001-10-14.bc mgs_hga_ck_2001-10-15.bc mgs_hga_ck_2001-10-16.bc mgs_hga_ck_2001-10-17.bc mgs_hga_ck_2001-10-18.bc mgs_hga_ck_2001-10-19.bc mgs_hga_ck_2001-10-20.bc mgs_hga_ck_2001-10-21.bc mgs_hga_ck_2001-10-22.bc mgs_hga_ck_2001-10-23.bc mgs_hga_ck_2001-10-24.bc mgs_hga_ck_2001-10-25.bc mgs_hga_ck_2001-10-26.bc mgs_hga_ck_2001-10-27.bc mgs_hga_ck_2001-10-28.bc mgs_hga_ck_2001-10-29.bc mgs_hga_ck_2001-10-30.bc mgs_hga_ck_2001-10-31.bc mgs_hga_ck_2001-11-01.bc mgs_hga_ck_2001-11-02.bc mgs_hga_ck_2001-11-03.bc mgs_hga_ck_2001-11-04.bc mgs_hga_ck_2001-11-05.bc mgs_hga_ck_2001-11-06.bc mgs_hga_ck_2001-11-07.bc mgs_hga_ck_2001-11-08.bc mgs_hga_ck_2001-11-09.bc mgs_hga_ck_2001-11-10.bc mgs_hga_ck_2001-11-11.bc mgs_hga_ck_2001-11-12.bc mgs_hga_ck_2001-11-13.bc mgs_hga_ck_2001-11-14.bc mgs_hga_ck_2001-11-15.bc mgs_hga_ck_2001-11-16.bc mgs_hga_ck_2001-11-17.bc mgs_hga_ck_2001-11-18.bc mgs_hga_ck_2001-11-19.bc mgs_hga_ck_2001-11-20.bc mgs_hga_ck_2001-11-21.bc mgs_hga_ck_2001-11-22.bc mgs_hga_ck_2001-11-23.bc mgs_hga_ck_2001-11-24.bc mgs_hga_ck_2001-11-25.bc mgs_hga_ck_2001-11-26.bc mgs_hga_ck_2001-11-27.bc mgs_hga_ck_2001-11-28.bc mgs_hga_ck_2001-11-29.bc mgs_hga_ck_2001-11-30.bc mgs_hga_ck_2001-12-01.bc mgs_hga_ck_2001-12-02.bc mgs_hga_ck_2001-12-03.bc mgs_hga_ck_2001-12-04.bc mgs_hga_ck_2001-12-05.bc mgs_hga_ck_2001-12-06.bc mgs_hga_ck_2001-12-07.bc mgs_hga_ck_2001-12-08.bc mgs_hga_ck_2001-12-09.bc mgs_hga_ck_2001-12-10.bc mgs_hga_ck_2001-12-11.bc Appendix 2: Interpolation Intervals for HGA EL and AZ gimbals -------------------------------------------------------- Table contains start and stop UTC time for each interval. 2001-09-19T00:00:22.847 2001-09-19T17:06:30.838 2001-09-19T17:16:06.838 2001-09-19T17:22:30.838 2001-09-19T17:43:18.838 2001-09-19T17:48:06.838 2001-09-19T18:04:06.838 2001-09-23T22:42:30.785 2001-09-23T22:53:42.785 2001-10-09T03:05:46.595 2001-10-09T05:33:30.594 2001-10-12T22:39:38.548 2001-10-12T22:53:30.548 2001-10-15T17:06:18.513 2001-10-15T17:13:14.513 2001-10-15T23:39:22.510 2001-10-15T23:50:34.510 2001-10-17T00:26:18.497 2001-10-17T02:04:58.496 2001-10-17T02:06:02.496 2001-10-17T02:49:46.496 2001-10-17T02:51:54.496 2001-10-17T04:02:50.495 2001-10-17T04:03:54.495 2001-10-17T04:47:38.495 2001-10-17T04:49:46.495 2001-10-17T06:00:42.494 2001-10-17T06:01:14.494 2001-10-17T06:45:30.494 2001-10-17T06:47:06.494 2001-10-17T07:58:34.493 2001-10-17T07:59:06.493 2001-10-17T08:43:22.493 2001-10-17T08:52:58.493 2001-10-17T09:23:22.492 2001-10-17T09:54:18.492 2001-10-17T10:43:54.492 2001-10-17T11:52:10.491 2001-10-17T12:41:14.491 2001-10-17T13:49:30.490 2001-10-17T16:36:58.488 2001-10-17T17:45:14.488 2001-10-17T18:34:18.487 2001-10-17T19:43:06.487 2001-10-17T20:32:10.486 2001-10-17T21:40:58.486 2001-10-17T22:30:02.485 2001-10-17T23:38:18.485 2001-10-18T01:14:18.484 2001-10-18T08:10:50.480 2001-10-18T08:16:10.480 2001-10-18T13:22:18.478 2001-10-18T16:13:30.476 2001-10-18T17:18:02.476 2001-10-18T18:54:02.475 2001-10-19T04:52:26.470 2001-10-19T13:42:38.465 2001-10-19T13:42:38.465 2001-10-19T13:50:06.465 2001-10-19T13:50:06.465 2001-10-19T14:23:42.465 2001-10-19T14:23:42.465 2001-10-19T15:53:18.464 2001-10-19T15:53:18.464 2001-10-19T16:26:54.463 2001-10-19T16:26:54.463 2001-10-19T17:41:34.463 2001-10-19T17:41:34.463 2001-10-19T17:49:02.463 2001-10-19T18:33:50.462 2001-10-19T18:52:30.462 2001-10-19T18:56:14.462 2001-10-19T19:07:26.462 2001-10-19T19:37:18.462 2001-10-19T19:55:58.462 2001-10-19T19:55:58.462 2001-10-19T22:29:02.460 2001-10-19T22:47:42.460 2001-10-19T23:10:06.460 2001-10-19T23:10:06.460 2001-10-19T23:26:54.460 2001-10-20T02:18:38.458 2001-10-20T02:26:06.458 2001-10-20T04:55:26.457 2001-10-20T06:13:50.456 2001-10-20T06:21:18.456 2001-10-20T06:43:42.456 2001-10-20T07:02:22.456 2001-10-20T07:39:42.455 2001-10-20T07:39:42.455 2001-10-20T08:05:50.455 2001-10-20T08:24:30.455 2001-10-20T09:05:34.455 2001-10-20T09:05:34.455 2001-10-20T09:27:58.454 2001-10-20T09:46:38.454 2001-10-20T10:12:46.454 2001-10-20T10:23:58.454 2001-10-20T10:50:06.454 2001-10-20T11:05:02.454 2001-10-20T11:34:54.453 2001-10-20T11:46:06.453 2001-10-20T12:15:58.453 2001-10-20T12:23:26.453 2001-10-20T12:57:02.453 2001-10-20T13:08:14.453 2001-10-20T13:38:06.452 2001-10-20T13:49:18.452 2001-10-20T14:22:54.452 2001-10-20T14:30:22.452 2001-10-20T16:18:38.451 2001-10-20T16:33:34.451 2001-10-20T16:59:42.450 2001-10-20T17:14:38.450 2001-10-20T17:37:02.450 2001-10-20T17:55:42.450 2001-10-20T18:14:22.450 2001-10-20T18:36:46.450 2001-10-20T19:02:54.449 2001-10-20T19:17:50.449 2001-10-20T21:58:22.448 2001-10-20T22:02:06.448 2001-10-20T22:31:58.448 2001-10-20T22:43:10.447 2001-10-20T23:09:18.447 2001-10-20T23:24:14.447 2001-10-20T23:42:54.447 2001-10-21T00:05:18.447 2001-10-21T03:25:30.445 2001-10-21T04:08:10.445 2001-10-21T04:58:50.444 2001-10-21T06:08:10.444 2001-10-21T06:52:58.443 2001-10-21T07:15:22.443 2001-10-21T07:56:58.443 2001-10-21T08:02:50.443 2001-10-21T08:50:18.442 2001-10-21T10:00:42.441 2001-10-21T10:46:34.441 2001-10-21T10:52:58.441 2001-10-21T14:42:18.439 2001-10-21T15:42:34.438 2001-10-21T16:46:58.438 2001-10-21T17:37:38.437 2001-10-21T18:49:06.437 2001-10-21T19:49:38.436 2001-10-21T20:35:30.436 2001-10-21T21:47:30.435 2001-10-21T22:36:02.435 2001-10-21T23:44:50.434 2001-10-22T00:33:54.434 2001-10-22T01:03:14.434 2001-10-22T01:09:38.433 2001-10-22T01:42:42.433 2001-10-22T02:31:46.433 2001-10-22T03:40:34.432 2001-10-22T04:29:38.432 2001-10-22T05:37:54.431 2001-10-22T07:37:54.430 2001-10-22T07:41:06.430 2001-10-22T08:25:22.430 2001-10-22T09:36:18.429 2001-10-22T10:22:42.429 2001-10-22T23:20:50.422 2001-10-23T01:17:38.421 2001-10-23T01:20:50.421 2001-10-23T02:01:54.420 2001-10-30T07:57:06.328 2001-10-30T08:20:34.328 2001-10-31T07:29:54.316 2001-10-31T08:57:54.315 2001-11-11T08:24:50.176 2001-11-11T10:22:10.175 2001-11-11T10:24:50.175 2001-11-11T11:09:38.174 2001-11-12T14:55:14.159 2001-11-12T15:01:06.159 2001-11-12T15:01:06.159 2001-11-12T15:23:30.159 2001-11-12T22:18:58.156 2001-11-12T22:24:50.155 2001-11-14T07:03:14.138 2001-11-14T09:01:06.137 2001-11-14T09:03:14.137 2001-11-14T09:24:02.137 2001-11-20T21:59:46.054 2001-11-20T22:10:26.054 2001-11-22T21:05:54.029 2001-11-22T21:44:18.029 2001-11-29T10:11:29.946 2001-11-29T10:17:21.946 2001-12-01T17:01:37.917 2001-12-01T17:26:41.917 2001-12-07T08:24:49.845 2001-12-07T08:42:57.845 2001-12-09T19:17:05.814 2001-12-09T19:48:33.814 2001-12-10T07:03:45.808 2001-12-10T07:25:05.808 2001-12-11T18:22:49.789 2001-12-11T18:43:05.789 2001-12-11T23:59:53.786 " END