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_ext3.bc" PRODUCT_ID = "1178261A.AGK" FILE_NAME = "1178261A.AGK" START_TIME = 2001-06-27T00:00:31.887Z STOP_TIME = 2001-09-18T23:59:50.848Z PRODUCT_CREATION_TIME = 2001-11-25T00:00:00 PRODUCER_ID = NAIF ^DESCRIPTION = "TK_FTP.TXT" NOTE = " MGS HGA Gimbals CK File for Extended Mission, Mapping Cycles 31-33 =========================================================================== Created by Boris Semenov, NAIF/JPL, November 25, 2001 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 31st, 32nd, and 33rd 28-day mapping cycles of the Extended phase of the mission: COVERAGE BEGIN TIME (UTC): 2001-JUN-27 00:00:31.887 COVERAGE END TIME (UTC): 2001-SEP-18 23:59:50.847 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_2001-06-27.bc mgs_hga_ck_2001-06-28.bc mgs_hga_ck_2001-06-29.bc mgs_hga_ck_2001-06-30.bc mgs_hga_ck_2001-07-01.bc mgs_hga_ck_2001-07-02.bc mgs_hga_ck_2001-07-03.bc mgs_hga_ck_2001-07-04.bc mgs_hga_ck_2001-07-05.bc mgs_hga_ck_2001-07-06.bc mgs_hga_ck_2001-07-07.bc mgs_hga_ck_2001-07-08.bc mgs_hga_ck_2001-07-09.bc mgs_hga_ck_2001-07-10.bc mgs_hga_ck_2001-07-11.bc mgs_hga_ck_2001-07-12.bc mgs_hga_ck_2001-07-13.bc mgs_hga_ck_2001-07-14.bc mgs_hga_ck_2001-07-15.bc mgs_hga_ck_2001-07-16.bc mgs_hga_ck_2001-07-17.bc mgs_hga_ck_2001-07-18.bc mgs_hga_ck_2001-07-19.bc mgs_hga_ck_2001-07-20.bc mgs_hga_ck_2001-07-21.bc mgs_hga_ck_2001-07-22.bc mgs_hga_ck_2001-07-23.bc mgs_hga_ck_2001-07-24.bc mgs_hga_ck_2001-07-25.bc mgs_hga_ck_2001-07-26.bc mgs_hga_ck_2001-07-27.bc mgs_hga_ck_2001-07-28.bc mgs_hga_ck_2001-07-29.bc mgs_hga_ck_2001-07-30.bc mgs_hga_ck_2001-07-31.bc mgs_hga_ck_2001-08-01.bc mgs_hga_ck_2001-08-02.bc mgs_hga_ck_2001-08-03.bc mgs_hga_ck_2001-08-04.bc mgs_hga_ck_2001-08-05.bc mgs_hga_ck_2001-08-06.bc mgs_hga_ck_2001-08-07.bc mgs_hga_ck_2001-08-08.bc mgs_hga_ck_2001-08-09.bc mgs_hga_ck_2001-08-10.bc mgs_hga_ck_2001-08-11.bc mgs_hga_ck_2001-08-12.bc mgs_hga_ck_2001-08-13.bc mgs_hga_ck_2001-08-14.bc mgs_hga_ck_2001-08-15.bc mgs_hga_ck_2001-08-16.bc mgs_hga_ck_2001-08-17.bc mgs_hga_ck_2001-08-18.bc mgs_hga_ck_2001-08-19.bc mgs_hga_ck_2001-08-20.bc mgs_hga_ck_2001-08-21.bc mgs_hga_ck_2001-08-22.bc mgs_hga_ck_2001-08-23.bc mgs_hga_ck_2001-08-24.bc mgs_hga_ck_2001-08-25.bc mgs_hga_ck_2001-08-26.bc mgs_hga_ck_2001-08-27.bc mgs_hga_ck_2001-08-28.bc mgs_hga_ck_2001-08-29.bc mgs_hga_ck_2001-08-30.bc mgs_hga_ck_2001-08-31.bc mgs_hga_ck_2001-09-01.bc mgs_hga_ck_2001-09-02.bc mgs_hga_ck_2001-09-03.bc mgs_hga_ck_2001-09-04.bc mgs_hga_ck_2001-09-05.bc mgs_hga_ck_2001-09-06.bc mgs_hga_ck_2001-09-07.bc mgs_hga_ck_2001-09-08.bc mgs_hga_ck_2001-09-09.bc mgs_hga_ck_2001-09-10.bc mgs_hga_ck_2001-09-11.bc mgs_hga_ck_2001-09-12.bc mgs_hga_ck_2001-09-13.bc mgs_hga_ck_2001-09-14.bc mgs_hga_ck_2001-09-15.bc mgs_hga_ck_2001-09-16.bc mgs_hga_ck_2001-09-17.bc mgs_hga_ck_2001-09-18.bc Appendix 2: Interpolation Intervals for HGA EL and AZ gimbals -------------------------------------------------------- Table contains start and stop UTC time for each interval. 2001-06-27T00:00:31.887 2001-06-29T07:43:27.858 2001-06-29T08:19:11.858 2001-06-29T08:24:31.858 2001-06-29T08:36:15.858 2001-06-29T08:36:47.858 2001-06-29T08:44:15.858 2001-06-29T09:46:39.857 2001-06-29T09:53:03.857 2001-06-30T00:26:07.850 2001-06-30T00:50:39.849 2001-07-01T23:47:11.825 2001-07-01T23:54:39.825 2001-07-04T18:00:31.791 2001-07-04T18:17:35.791 2001-07-05T05:59:27.785 2001-07-05T06:10:39.785 2001-07-18T00:26:07.627 2001-07-18T00:39:27.627 2001-07-18T00:51:43.627 2001-07-18T04:35:11.625 2001-07-18T04:41:35.625 2001-07-18T05:11:59.625 2001-07-24T01:10:23.553 2001-07-24T01:23:11.553 2001-07-25T01:09:19.540 2001-07-25T01:17:19.540 2001-07-25T22:39:27.529 2001-07-25T22:54:23.529 2001-07-27T06:48:31.513 2001-07-27T06:55:59.513 2001-07-29T01:06:39.491 2001-07-29T01:22:39.491 2001-08-03T00:26:07.429 2001-08-03T01:03:27.429 2001-08-05T17:17:51.396 2001-08-05T17:58:55.396 2001-08-05T22:39:27.393 2001-08-05T22:53:19.393 2001-08-06T22:39:27.381 2001-08-06T22:53:19.381 2001-08-07T08:57:35.375 2001-08-07T09:06:07.375 2001-08-07T18:07:27.371 2001-08-07T22:15:59.369 2001-08-13T02:03:11.305 2001-08-13T02:19:43.305 2001-08-15T01:01:51.281 2001-08-15T01:10:55.280 2001-08-15T01:57:19.280 2001-08-15T02:13:19.280 2001-08-15T02:13:51.280 2001-08-15T02:19:43.280 2001-08-15T02:22:55.280 2001-08-15T02:37:19.280 2001-08-15T09:55:43.276 2001-08-15T10:02:07.276 2001-08-15T16:23:27.273 2001-08-15T16:31:27.273 2001-08-16T00:26:07.268 2001-08-16T02:30:23.267 2001-08-16T02:35:11.267 2001-08-16T03:16:47.267 2001-08-16T03:18:55.267 2001-08-16T04:28:15.266 2001-08-16T04:33:03.266 2001-08-16T05:15:11.266 2001-08-16T05:16:47.266 2001-08-16T05:54:07.266 2001-08-20T16:30:23.211 2001-08-20T16:36:47.211 2001-08-22T00:26:07.194 2001-08-22T02:53:19.193 2001-08-22T03:01:51.193 2001-08-22T03:07:11.193 2001-09-06T05:34:23.006 2001-09-06T11:35:11.003 2001-09-06T11:42:39.003 2001-09-06T12:12:31.002 2001-09-06T12:23:43.002 2001-09-07T00:41:02.996 2001-09-07T00:41:02.996 2001-09-07T01:22:06.996 2001-09-07T01:22:06.996 2001-09-07T01:55:42.995 2001-09-07T02:03:10.995 2001-09-07T02:33:02.995 2001-09-07T02:59:10.995 2001-09-07T03:06:38.995 2001-09-07T03:17:50.995 2001-09-07T05:06:06.994 2001-09-07T05:24:46.994 2001-09-07T05:41:34.993 2001-09-07T06:03:58.993 2001-09-07T06:11:26.993 2001-09-07T06:11:26.993 2001-09-07T06:22:38.993 2001-09-07T09:21:50.992 2001-09-07T10:02:54.991 2001-09-07T10:02:54.991 2001-09-07T10:25:18.991 2001-09-07T10:43:58.991 2001-09-07T11:17:34.991 2001-09-07T11:25:02.991 2001-09-07T11:54:54.990 2001-09-07T12:06:06.990 2001-09-07T12:28:30.990 2001-09-07T12:47:10.990 2001-09-07T14:01:50.989 2001-09-07T14:05:34.989 2001-09-08T02:21:02.983 2001-09-08T02:24:46.983 2001-09-08T03:02:06.982 2001-09-08T03:05:50.982 2001-09-08T03:31:58.982 2001-09-08T03:46:54.982 2001-09-08T04:09:18.982 2001-09-08T04:27:58.982 2001-09-08T04:54:06.981 2001-09-08T05:09:02.981 2001-09-08T05:31:26.981 2001-09-08T05:46:22.981 2001-09-08T06:52:46.980 2001-09-08T08:19:10.980 2001-09-08T08:33:02.980 2001-09-08T08:57:02.979 2001-09-08T09:39:10.979 2001-09-08T10:16:30.979 2001-09-08T10:28:46.979 2001-09-08T12:13:50.978 2001-09-08T12:27:42.978 2001-09-08T12:31:58.978 2001-09-08T12:37:50.977 2001-09-08T13:44:30.977 2001-09-08T14:31:26.977 2001-09-08T15:10:54.976 2001-09-08T15:28:30.976 2001-09-08T15:42:22.976 2001-09-08T16:33:34.975 2001-09-08T17:40:14.975 2001-09-08T18:30:54.974 2001-09-08T19:37:34.974 2001-09-08T20:28:46.973 2001-09-08T21:35:18.973 2001-09-08T22:44:06.972 2001-09-08T23:33:10.972 2001-09-09T00:24:22.971 2001-09-09T01:30:30.971 2001-09-09T02:22:14.970 2001-09-09T03:28:22.970 2001-09-09T04:20:06.969 2001-09-09T05:26:14.969 2001-09-09T06:15:50.968 2001-09-09T07:24:06.968 2001-09-09T08:15:18.967 2001-09-09T09:21:26.967 2001-09-09T10:13:10.966 2001-09-09T11:19:18.966 2001-09-09T12:13:42.965 2001-09-09T13:17:10.965 2001-09-09T14:04:38.964 2001-09-09T15:15:02.964 2001-09-10T00:08:54.959 2001-09-10T01:03:50.959 2001-09-10T01:51:50.958 2001-09-10T03:01:42.958 2001-09-10T03:48:38.957 2001-09-10T04:59:34.957 2001-09-10T05:50:46.956 2001-09-10T05:53:26.956 2001-09-10T08:55:50.955 2001-09-10T08:59:34.955 2001-09-10T10:53:42.954 2001-09-10T10:57:26.954 2001-09-10T12:51:34.953 2001-09-10T12:55:18.953 2001-09-10T14:48:54.952 2001-09-10T14:53:10.952 2001-09-11T04:33:26.945 2001-09-11T04:37:10.945 2001-09-11T05:19:18.944 2001-09-11T05:21:58.944 2001-09-11T06:31:18.944 2001-09-11T06:35:02.943 2001-09-11T07:17:42.943 2001-09-11T07:19:50.943 2001-09-11T08:29:10.943 2001-09-11T08:32:54.942 2001-09-11T09:15:34.942 2001-09-11T09:17:10.942 2001-09-11T10:26:30.941 2001-09-11T10:30:14.941 2001-09-11T11:13:26.941 2001-09-11T11:19:50.941 2001-09-11T11:50:14.941 2001-09-11T12:28:06.940 2001-09-11T13:11:18.940 2001-09-11T14:21:10.939 2001-09-11T15:08:06.939 2001-09-11T15:18:46.939 2001-09-11T17:43:18.938 2001-09-11T18:16:22.937 2001-09-11T19:04:22.937 2001-09-11T20:14:14.936 2001-09-11T21:01:42.936 2001-09-11T22:12:06.935 2001-09-11T23:34:14.935 2001-09-12T00:09:26.934 2001-09-12T00:56:54.934 2001-09-12T02:07:18.933 2001-09-12T02:55:18.933 2001-09-12T04:05:10.932 2001-09-12T04:52:06.932 2001-09-12T06:03:02.931 2001-09-12T06:51:02.931 2001-09-12T08:00:54.930 2001-09-12T08:48:54.930 2001-09-12T09:58:46.929 2001-09-12T10:46:14.929 2001-09-12T11:56:06.928 2001-09-12T12:44:06.928 2001-09-12T13:53:58.927 2001-09-12T14:40:22.927 2001-09-12T15:15:02.927 2001-09-13T00:00:22.922 2001-09-13T11:34:14.916 2001-09-13T12:16:22.916 2001-09-13T12:18:30.916 2001-09-13T13:27:50.915 2001-09-13T13:31:34.915 2001-09-13T14:13:42.915 2001-09-13T15:08:38.914 2001-09-13T22:53:42.910 2001-09-14T22:39:50.898 2001-09-14T22:53:42.898 2001-09-18T22:32:54.848 2001-09-18T22:53:42.848 2001-09-18T23:59:50.847 " END