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_ext5.bc" PRODUCT_ID = "1346064A.AGK" FILE_NAME = "1346064A.AGK" START_TIME = 2001-12-12T00:00:25.786Z STOP_TIME = 2002-03-05T23:33:16.701Z PRODUCT_CREATION_TIME = 2002-04-22T00:00:00 PRODUCER_ID = NAIF ^DESCRIPTION = "TK_FTP.TXT" NOTE = " MGS HGA Gimbals CK File for Extended Mission, Mapping Cycles 37-39 =========================================================================== Created by Boris Semenov, NAIF/JPL, April 22, 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 37th, 38th, and 39th 28-day mapping cycles of the Extended phase of the mission: COVERAGE BEGIN TIME (UTC): 2001-12-12T00:00:25.786 COVERAGE END TIME (UTC): 2002-03-05T23:33:16.701 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.00043.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_2001-12-12.bc mgs_hga_ck_2001-12-13.bc mgs_hga_ck_2001-12-14.bc mgs_hga_ck_2001-12-15.bc mgs_hga_ck_2001-12-16.bc mgs_hga_ck_2001-12-17.bc mgs_hga_ck_2001-12-18.bc mgs_hga_ck_2001-12-19.bc mgs_hga_ck_2001-12-20.bc mgs_hga_ck_2001-12-21.bc mgs_hga_ck_2001-12-22.bc mgs_hga_ck_2001-12-23.bc mgs_hga_ck_2001-12-24.bc mgs_hga_ck_2001-12-25.bc mgs_hga_ck_2001-12-26.bc mgs_hga_ck_2001-12-27.bc mgs_hga_ck_2001-12-28.bc mgs_hga_ck_2001-12-29.bc mgs_hga_ck_2001-12-30.bc mgs_hga_ck_2001-12-31.bc mgs_hga_ck_2002-01-01.bc mgs_hga_ck_2002-01-02.bc mgs_hga_ck_2002-01-03.bc mgs_hga_ck_2002-01-04.bc mgs_hga_ck_2002-01-05.bc mgs_hga_ck_2002-01-06.bc mgs_hga_ck_2002-01-07.bc mgs_hga_ck_2002-01-08.bc mgs_hga_ck_2002-01-09.bc mgs_hga_ck_2002-01-10.bc mgs_hga_ck_2002-01-11.bc mgs_hga_ck_2002-01-12.bc mgs_hga_ck_2002-01-13.bc mgs_hga_ck_2002-01-14.bc mgs_hga_ck_2002-01-15.bc mgs_hga_ck_2002-01-16.bc mgs_hga_ck_2002-01-17.bc mgs_hga_ck_2002-01-18.bc mgs_hga_ck_2002-01-19.bc mgs_hga_ck_2002-01-20.bc mgs_hga_ck_2002-01-21.bc mgs_hga_ck_2002-01-22.bc mgs_hga_ck_2002-01-23.bc mgs_hga_ck_2002-01-24.bc mgs_hga_ck_2002-01-25.bc mgs_hga_ck_2002-01-26.bc mgs_hga_ck_2002-01-27.bc mgs_hga_ck_2002-01-28.bc mgs_hga_ck_2002-01-29.bc mgs_hga_ck_2002-01-30.bc mgs_hga_ck_2002-01-31.bc mgs_hga_ck_2002-02-01.bc mgs_hga_ck_2002-02-02.bc mgs_hga_ck_2002-02-03.bc mgs_hga_ck_2002-02-04.bc mgs_hga_ck_2002-02-05.bc mgs_hga_ck_2002-02-06.bc mgs_hga_ck_2002-02-07.bc mgs_hga_ck_2002-02-08.bc mgs_hga_ck_2002-02-09.bc mgs_hga_ck_2002-02-10.bc mgs_hga_ck_2002-02-11.bc mgs_hga_ck_2002-02-12.bc mgs_hga_ck_2002-02-13.bc mgs_hga_ck_2002-02-14.bc mgs_hga_ck_2002-02-15.bc mgs_hga_ck_2002-02-16.bc mgs_hga_ck_2002-02-17.bc mgs_hga_ck_2002-02-18.bc mgs_hga_ck_2002-02-19.bc mgs_hga_ck_2002-02-20.bc mgs_hga_ck_2002-02-21.bc mgs_hga_ck_2002-02-22.bc mgs_hga_ck_2002-02-23.bc mgs_hga_ck_2002-02-24.bc mgs_hga_ck_2002-02-25.bc mgs_hga_ck_2002-02-26.bc mgs_hga_ck_2002-02-27.bc mgs_hga_ck_2002-03-01.bc mgs_hga_ck_2002-03-02.bc mgs_hga_ck_2002-03-03.bc mgs_hga_ck_2002-03-04.bc mgs_hga_ck_2002-03-05.bc Appendix 2: Interpolation Intervals for HGA EL and AZ gimbals -------------------------------------------------------- Table contains start and stop UTC time for each interval. 2001-12-12T00:00:25.786 2001-12-13T23:23:05.761 2001-12-14T00:25:29.760 2001-12-14T11:09:45.755 2001-12-14T12:10:33.754 2001-12-17T15:41:13.714 2001-12-17T15:57:45.714 2001-12-18T21:07:37.698 2001-12-18T21:18:17.698 2001-12-19T14:46:49.689 2001-12-19T15:04:57.689 2001-12-21T07:59:21.667 2001-12-21T08:32:57.667 2001-12-31T21:07:37.533 2001-12-31T22:52:09.532 2001-12-31T23:07:05.532 2001-12-31T23:43:53.532 2002-01-06T14:44:09.460 2002-01-06T14:51:05.460 2002-01-07T23:51:21.443 2002-01-07T23:57:45.443 2002-01-11T10:16:25.399 2002-01-11T10:38:17.398 2002-01-15T06:23:21.349 2002-01-15T06:58:01.349 2002-01-22T22:56:57.250 2002-01-22T23:09:13.250 2002-01-22T23:14:01.250 2002-01-22T23:20:57.250 2002-01-23T04:50:33.247 2002-01-23T06:36:09.246 2002-01-23T06:47:53.246 2002-01-23T07:28:57.246 2002-01-23T08:39:21.245 2002-01-23T09:04:25.245 2002-01-25T15:42:17.215 2002-01-25T15:52:57.215 2002-01-30T07:33:13.154 2002-01-30T07:49:45.154 2002-02-01T11:32:41.125 2002-02-01T11:50:17.125 2002-02-04T11:32:41.086 2002-02-04T12:57:29.086 2002-02-04T13:01:45.086 2002-02-04T14:55:21.084 2002-02-04T14:59:37.084 2002-02-04T16:52:41.083 2002-02-04T16:56:57.083 2002-02-04T18:50:33.082 2002-02-04T18:54:49.082 2002-02-04T19:40:09.082 2002-02-04T20:52:41.081 2002-02-04T21:38:33.081 2002-02-05T03:25:45.078 2002-02-05T04:29:13.077 2002-02-09T14:31:53.019 2002-02-09T15:01:13.019 2002-02-13T15:02:48.967 2002-02-13T15:11:52.967 2002-02-13T16:01:28.966 2002-02-13T16:31:20.966 2002-02-13T23:20:24.962 2002-02-13T23:27:20.962 2002-02-14T21:10:48.951 2002-02-14T21:20:24.951 2002-02-22T11:33:12.851 2002-02-22T13:07:36.851 2002-02-27T20:54:16.781 2002-03-01T23:02:16.754 2002-03-01T23:02:16.754 2002-03-02T01:01:44.753 2002-03-02T01:09:12.753 2002-03-02T05:00:40.751 2002-03-02T05:11:52.751 2002-03-02T05:52:56.750 2002-03-02T07:11:20.749 2002-03-02T07:59:52.749 2002-03-02T09:07:04.748 2002-03-02T12:28:40.747 2002-03-02T13:02:16.746 2002-03-02T15:54:00.745 2002-03-02T16:57:28.744 2002-03-02T17:38:32.744 2002-03-02T17:46:00.744 2002-03-02T17:57:12.744 2002-03-02T18:56:56.743 2002-03-02T19:38:00.743 2002-03-02T20:52:40.742 2002-03-02T21:41:12.742 2002-03-02T22:52:08.741 2002-03-02T23:36:56.741 2002-03-03T00:14:16.740 2002-03-03T00:21:44.740 2002-03-03T00:29:12.740 2002-03-03T01:32:40.739 2002-03-03T01:47:36.739 2002-03-03T02:06:16.739 2002-03-03T02:06:16.739 2002-03-03T02:28:40.739 2002-03-03T02:32:24.739 2002-03-03T03:30:16.738 2002-03-03T04:30:00.738 2002-03-03T17:26:32.731 2002-03-03T18:30:00.730 2002-03-03T19:14:48.730 2002-03-03T20:25:44.729 2002-03-03T21:21:44.729 2002-03-03T22:25:12.728 2002-03-03T23:06:16.728 2002-03-03T23:28:40.728 2002-03-04T07:34:00.723 2002-03-04T08:07:36.723 2002-03-04T09:48:24.722 2002-03-04T09:48:24.722 2002-03-04T09:59:36.722 2002-03-04T09:59:36.722 2002-03-04T10:51:52.721 2002-03-04T11:40:24.721 2002-03-04T11:51:36.721 2002-03-04T12:10:16.721 2002-03-04T12:51:20.720 2002-03-04T13:02:32.720 2002-03-04T13:10:00.720 2002-03-04T13:10:00.720 2002-03-04T13:17:28.720 2002-03-04T14:06:00.720 2002-03-04T14:47:04.719 2002-03-04T14:47:04.719 2002-03-04T14:54:32.719 2002-03-04T14:58:16.719 2002-03-04T15:05:44.719 2002-03-04T15:05:44.719 2002-03-04T15:13:12.719 2002-03-04T15:31:52.719 2002-03-04T15:39:20.719 2002-03-04T16:01:44.719 2002-03-04T16:46:32.718 2002-03-04T18:01:12.717 2002-03-04T18:42:16.717 2002-03-04T19:15:52.717 2002-03-04T20:56:40.716 2002-03-04T21:52:40.715 2002-03-04T22:37:28.715 2002-03-04T22:37:28.715 2002-03-04T22:52:24.715 2002-03-04T23:22:16.715 2002-03-05T01:14:16.714 2002-03-05T01:18:00.714 2002-03-05T01:25:28.713 2002-03-05T01:25:28.713 2002-03-05T01:36:40.713 2002-03-05T01:51:36.713 2002-03-05T03:43:36.712 2002-03-05T03:51:04.712 2002-03-05T05:39:20.711 2002-03-05T05:39:20.711 2002-03-05T05:46:48.711 2002-03-05T05:46:48.711 2002-03-05T06:39:04.711 2002-03-05T07:46:16.710 2002-03-05T08:38:32.710 2002-03-05T09:27:04.709 2002-03-05T09:38:16.709 2002-03-05T09:42:00.709 2002-03-05T10:23:04.709 2002-03-05T11:41:28.708 2002-03-05T12:22:32.708 2002-03-05T12:33:44.707 2002-03-05T13:03:36.707 2002-03-05T13:07:20.707 2002-03-05T13:24:08.707 2002-03-05T13:35:20.707 2002-03-05T14:38:48.706 2002-03-05T15:34:48.706 2002-03-05T16:15:52.705 2002-03-05T16:19:36.705 2002-03-05T16:34:32.705 2002-03-05T17:30:32.705 2002-03-05T18:15:20.704 2002-03-05T18:15:20.704 2002-03-05T18:34:00.704 2002-03-05T19:30:00.704 2002-03-05T20:11:04.703 2002-03-05T20:11:04.703 2002-03-05T20:29:44.703 2002-03-05T21:03:20.703 2002-03-05T22:14:16.702 2002-03-05T22:14:16.702 2002-03-05T22:35:40.702 2002-03-05T23:33:16.701 " END