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_ext15.bc" PRODUCT_ID = "4091174A.AGK" FILE_NAME = "4091174A.AGK" START_TIME = 2004-03-31T00:01:06.222 STOP_TIME = 2004-06-22T23:59:28.984 PRODUCT_CREATION_TIME = 2004-08-12T00:00:00 PRODUCER_ID = NAIF ^DESCRIPTION = "TK_FTP.TXT" NOTE = " MGS HGA Gimbals CK File for Extended Mission, Mapping Cycles 67-69 =========================================================================== Created by Boris Semenov, NAIF/JPL, August 12, 2004 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 67th, 68th, and 69th 28-day mapping cycles of the Extended phase of the mission: COVERAGE BEGIN TIME (UTC): 2004-MAR-31 00:01:06.222 COVERAGE END TIME (UTC): 2004-JUN-22 23:59:28.984 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.00054.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_2004-03-31.bc mgs_hga_ck_2004-04-01.bc mgs_hga_ck_2004-04-02.bc mgs_hga_ck_2004-04-03.bc mgs_hga_ck_2004-04-04.bc mgs_hga_ck_2004-04-05.bc mgs_hga_ck_2004-04-06.bc mgs_hga_ck_2004-04-07.bc mgs_hga_ck_2004-04-08.bc mgs_hga_ck_2004-04-09.bc mgs_hga_ck_2004-04-10.bc mgs_hga_ck_2004-04-11.bc mgs_hga_ck_2004-04-12.bc mgs_hga_ck_2004-04-13.bc mgs_hga_ck_2004-04-14.bc mgs_hga_ck_2004-04-15.bc mgs_hga_ck_2004-04-16.bc mgs_hga_ck_2004-04-17.bc mgs_hga_ck_2004-04-18.bc mgs_hga_ck_2004-04-19.bc mgs_hga_ck_2004-04-20.bc mgs_hga_ck_2004-04-21.bc mgs_hga_ck_2004-04-22.bc mgs_hga_ck_2004-04-23.bc mgs_hga_ck_2004-04-24.bc mgs_hga_ck_2004-04-25.bc mgs_hga_ck_2004-04-26.bc mgs_hga_ck_2004-04-27.bc mgs_hga_ck_2004-04-28.bc mgs_hga_ck_2004-04-29.bc mgs_hga_ck_2004-04-30.bc mgs_hga_ck_2004-05-01.bc mgs_hga_ck_2004-05-02.bc mgs_hga_ck_2004-05-03.bc mgs_hga_ck_2004-05-04.bc mgs_hga_ck_2004-05-05.bc mgs_hga_ck_2004-05-06.bc mgs_hga_ck_2004-05-07.bc mgs_hga_ck_2004-05-08.bc mgs_hga_ck_2004-05-09.bc mgs_hga_ck_2004-05-10.bc mgs_hga_ck_2004-05-11.bc mgs_hga_ck_2004-05-12.bc mgs_hga_ck_2004-05-13.bc mgs_hga_ck_2004-05-14.bc mgs_hga_ck_2004-05-15.bc mgs_hga_ck_2004-05-16.bc mgs_hga_ck_2004-05-17.bc mgs_hga_ck_2004-05-18.bc mgs_hga_ck_2004-05-19.bc mgs_hga_ck_2004-05-20.bc mgs_hga_ck_2004-05-21.bc mgs_hga_ck_2004-05-22.bc mgs_hga_ck_2004-05-23.bc mgs_hga_ck_2004-05-24.bc mgs_hga_ck_2004-05-25.bc mgs_hga_ck_2004-05-26.bc mgs_hga_ck_2004-05-27.bc mgs_hga_ck_2004-05-28.bc mgs_hga_ck_2004-05-29.bc mgs_hga_ck_2004-05-30.bc mgs_hga_ck_2004-05-31.bc mgs_hga_ck_2004-06-01.bc mgs_hga_ck_2004-06-02.bc mgs_hga_ck_2004-06-03.bc mgs_hga_ck_2004-06-04.bc mgs_hga_ck_2004-06-05.bc mgs_hga_ck_2004-06-06.bc mgs_hga_ck_2004-06-07.bc mgs_hga_ck_2004-06-08.bc mgs_hga_ck_2004-06-09.bc mgs_hga_ck_2004-06-10.bc mgs_hga_ck_2004-06-11.bc mgs_hga_ck_2004-06-12.bc mgs_hga_ck_2004-06-13.bc mgs_hga_ck_2004-06-14.bc mgs_hga_ck_2004-06-15.bc mgs_hga_ck_2004-06-16.bc mgs_hga_ck_2004-06-17.bc mgs_hga_ck_2004-06-18.bc mgs_hga_ck_2004-06-19.bc mgs_hga_ck_2004-06-20.bc mgs_hga_ck_2004-06-21.bc mgs_hga_ck_2004-06-22.bc Appendix 2: Interpolation Intervals for HGA EL and AZ gimbals -------------------------------------------------------- Table contains start and stop UTC time for each interval as displayed by CKBRIEF utility ran with ``-dump'' option: Segment No.: 1 Object: -94071 Interval Begin UTC Interval End UTC AV ------------------------ ------------------------ --- 2004-MAR-31 00:01:06.222 2004-APR-01 17:48:50.197 Y 2004-APR-01 18:06:58.197 2004-APR-02 14:17:06.184 Y 2004-APR-02 14:37:54.184 2004-APR-03 23:43:30.164 Y 2004-APR-04 00:01:06.164 2004-APR-05 10:36:50.143 Y 2004-APR-05 10:51:14.143 2004-APR-05 10:58:42.143 Y 2004-APR-05 11:39:14.142 2004-APR-05 11:39:14.142 Y 2004-APR-05 12:48:34.142 2004-APR-05 12:56:02.142 Y 2004-APR-05 13:37:38.141 2004-APR-14 03:09:22.016 Y 2004-APR-14 03:18:26.016 2004-APR-17 17:54:41.963 Y 2004-APR-17 18:00:01.963 2004-APR-17 23:43:29.959 Y 2004-APR-17 23:58:57.959 2004-APR-19 20:22:57.932 Y 2004-APR-19 20:35:45.931 2004-MAY-07 06:41:37.674 Y Segment No.: 2 Object: -94071 Interval Begin UTC Interval End UTC AV ------------------------ ------------------------ --- 2004-MAY-07 06:41:37.674 2004-MAY-18 11:54:09.508 Y 2004-MAY-18 12:01:05.508 2004-MAY-26 00:25:05.397 Y 2004-MAY-26 00:41:05.397 2004-JUN-03 05:59:29.276 Y 2004-JUN-03 06:04:49.275 2004-JUN-05 00:11:45.250 Y 2004-JUN-05 00:18:09.249 2004-JUN-05 00:20:49.249 Y 2004-JUN-05 00:27:45.249 2004-JUN-06 13:14:41.227 Y 2004-JUN-06 13:26:25.227 2004-JUN-06 13:26:25.227 Y 2004-JUN-06 13:31:45.227 2004-JUN-13 09:28:33.126 Y Segment No.: 3 Object: -94071 Interval Begin UTC Interval End UTC AV ------------------------ ------------------------ --- 2004-JUN-13 09:28:33.126 2004-JUN-14 13:04:01.109 Y 2004-JUN-14 13:13:37.109 2004-JUN-16 00:04:17.087 Y 2004-JUN-16 00:13:53.087 2004-JUN-16 11:54:09.080 Y 2004-JUN-16 12:05:21.080 2004-JUN-16 15:06:41.078 Y 2004-JUN-16 16:01:05.077 2004-JUN-16 16:05:53.077 Y 2004-JUN-16 16:49:37.077 2004-JUN-20 11:54:09.021 Y 2004-JUN-20 12:16:01.021 2004-JUN-20 12:19:45.020 Y 2004-JUN-20 13:04:01.020 2004-JUN-20 13:04:01.020 Y 2004-JUN-20 13:42:25.020 2004-JUN-22 23:59:28.984 Y Segment No.: 4 Object: -94072 Interval Begin UTC Interval End UTC AV ------------------------ ------------------------ --- 2004-MAR-31 00:01:06.222 2004-APR-01 17:48:50.197 Y 2004-APR-01 18:06:58.197 2004-APR-02 14:17:06.184 Y 2004-APR-02 14:37:54.184 2004-APR-03 23:43:30.164 Y 2004-APR-04 00:01:06.164 2004-APR-05 10:36:50.143 Y 2004-APR-05 10:51:14.143 2004-APR-05 10:58:42.143 Y 2004-APR-05 11:39:14.142 2004-APR-05 11:39:14.142 Y 2004-APR-05 12:48:34.142 2004-APR-05 12:56:02.142 Y 2004-APR-05 13:37:38.141 2004-APR-14 03:09:22.016 Y 2004-APR-14 03:18:26.016 2004-APR-17 17:54:41.963 Y 2004-APR-17 18:00:01.963 2004-APR-17 23:43:29.959 Y 2004-APR-17 23:58:57.959 2004-APR-19 20:22:57.932 Y 2004-APR-19 20:35:45.931 2004-MAY-07 06:41:37.674 Y Segment No.: 5 Object: -94072 Interval Begin UTC Interval End UTC AV ------------------------ ------------------------ --- 2004-MAY-07 06:41:37.674 2004-MAY-18 11:54:09.508 Y 2004-MAY-18 12:01:05.508 2004-MAY-26 00:25:05.397 Y 2004-MAY-26 00:41:05.397 2004-JUN-03 05:59:29.276 Y 2004-JUN-03 06:04:49.275 2004-JUN-05 00:11:45.250 Y 2004-JUN-05 00:18:09.249 2004-JUN-05 00:20:49.249 Y 2004-JUN-05 00:27:45.249 2004-JUN-06 13:14:41.227 Y 2004-JUN-06 13:26:25.227 2004-JUN-06 13:26:25.227 Y 2004-JUN-06 13:31:45.227 2004-JUN-13 09:28:33.126 Y Segment No.: 6 Object: -94072 Interval Begin UTC Interval End UTC AV ------------------------ ------------------------ --- 2004-JUN-13 09:28:33.126 2004-JUN-14 13:04:01.109 Y 2004-JUN-14 13:13:37.109 2004-JUN-16 00:04:17.087 Y 2004-JUN-16 00:13:53.087 2004-JUN-16 11:54:09.080 Y 2004-JUN-16 12:05:21.080 2004-JUN-16 15:06:41.078 Y 2004-JUN-16 16:01:05.077 2004-JUN-16 16:05:53.077 Y 2004-JUN-16 16:49:37.077 2004-JUN-20 11:54:09.021 Y 2004-JUN-20 12:16:01.021 2004-JUN-20 12:19:45.020 Y 2004-JUN-20 13:04:01.020 2004-JUN-20 13:04:01.020 Y 2004-JUN-20 13:42:25.020 2004-JUN-22 23:59:28.984 Y " END