Log file for SPACIT Version 7.1.1. ******************************************************************************** Comments From File: near_erosorbit_rs_v1.bsp \beginlabel PDS_VERSION_ID = PDS3 RECORD_TYPE = FIXED_LENGTH RECORD_BYTES = 1024 ^SPICE_KERNEL = "NEAR_EROSORBIT_RS_V1.BSP" MISSION_NAME = "NEAR EARTH ASTEROID RENDEZVOUS" SPACECRAFT_NAME = "NEAR EARTH ASTEROID RENDEZVOUS" DATA_SET_ID = "NEAR-A-SPICE-6-EROS/ORBIT-V1.0" KERNEL_TYPE_ID = SPK PRODUCT_ID = "NEAR_EROSORBIT_RS_V1.BSP" PRODUCT_CREATION_TIME = 2001-09-05T12:30:44 PRODUCER_ID = "NEAR-RS/JPL" MISSION_PHASE_NAME = EROS PRODUCT_VERSION_TYPE = ACTUAL PLATFORM_OR_MOUNTING_NAME = "N/A" START_TIME = 2000-02-14T15:58:56 STOP_TIME = 2001-02-12T15:13:56 SPACECRAFT_CLOCK_START_COUNT = "N/A" SPACECRAFT_CLOCK_STOP_COUNT = "N/A" TARGET_NAME = EROS INSTRUMENT_NAME = "N/A" NAIF_INSTRUMENT_ID = "N/A" SOURCE_PRODUCT_ID = "N/A" NOTE = "See comments in the file for details" OBJECT = SPICE_KERNEL INTERCHANGE_FORMAT = BINARY KERNEL_TYPE = EPHEMERIS DESCRIPTION = "NEAR spacecraft trajectory SPK file covering the Eros orbit phase of the mission created by merging reconstructed OD solution SPK files from the NEAR Radio Science Team/JPL. " END_OBJECT = SPICE_KERNEL \endlabel NEAR Eros Orbit SPK file, NEAR Radio Science Team Solution =========================================================================== Created by Boris Semenov, NAIF/JPL, July 17, 2001. Objects in the Ephemeris -------------------------------------------------------- This file contains ephemeris data for the Near Earth Asteroid Rendezvous (NEAR) spacecraft. NAIF ID code for NEAR is -93. Approximate Time Coverage -------------------------------------------------------- This file covers the whole Eros orbit phase of the mission: COVERAGE BEGIN TIME (ET) COVERAGE END TIME (ET) ------------------------ ------------------------ 2000 FEB 14 16:00:00.000 2001 FEB 12 15:15:00.000 Because the propulsion maneuvers were not modeled in the trajectory determination process, the file contain numerous gaps that usually start at the exact times of the maneuvers and extend at least for the maneuver duration. Therefore, the actual coverage of the file consists of 35 disjoint intervals summarized in this table: COVERAGE BEGIN TIME (ET) COVERAGE END TIME (ET) ------------------------ ------------------------ 2000 FEB 14 16:00:00.000 2000 FEB 24 17:01:04.184 2000 FEB 24 17:15:00.000 2000 APR 02 02:04:24.185 2000 APR 02 02:15:00.000 2000 APR 11 21:21:04.186 2000 APR 11 21:32:00.000 2000 APR 22 17:51:04.186 2000 APR 22 18:00:00.000 2000 APR 30 16:16:04.186 2000 APR 30 16:25:00.000 2000 JUL 07 18:01:04.185 2000 JUL 07 18:10:00.000 2000 JUL 14 03:01:04.184 2000 JUL 14 03:10:00.000 2000 JUL 24 17:01:04.184 2000 JUL 24 17:10:00.000 2000 JUL 31 20:01:04.184 2000 JUL 31 20:10:00.000 2000 AUG 08 23:26:04.182 2000 AUG 08 23:35:00.000 2000 AUG 26 23:26:04.186 2000 AUG 26 23:35:00.000 2000 SEP 05 23:01:04.186 2000 SEP 05 23:10:00.000 2000 OCT 13 05:46:04.182 2000 OCT 13 06:00:00.000 2000 OCT 20 21:41:04.182 2000 OCT 20 21:50:00.000 2000 OCT 25 22:11:04.182 2000 OCT 25 22:20:00.000 2000 OCT 26 17:41:04.182 2000 OCT 26 17:50:00.000 2000 NOV 03 03:01:04.182 2000 NOV 03 03:10:00.000 2000 DEC 07 15:21:04.182 2000 DEC 07 15:30:00.000 2000 DEC 13 20:16:04.182 2000 DEC 13 20:25:00.000 2001 JAN 24 16:06:04.185 2001 JAN 24 16:10:00.000 2001 JAN 28 01:26:04.185 2001 JAN 28 01:30:00.000 2001 JAN 28 18:06:04.185 2001 JAN 28 18:10:00.000 2001 FEB 02 08:52:04.185 2001 FEB 02 08:55:00.000 2001 FEB 06 17:45:00.000 2001 FEB 06 17:50:00.000 2001 FEB 12 15:15:00.000 Although most of the segments in the file don't overlap, some do. In cases when segments overlap, there can a trajectory discontinuity. These discontinuities are summarized in the Appendix 4 of these comments. Status -------------------------------------------------------- This SPK file contains NEAR orbit reconstruction provided by Alex Konopliv of the NEAR Radio Science Team and is essentially a side product of the gravity model determination performed by that team. Pedigree -------------------------------------------------------- The original SPK files used to make this file were created from a set of NIO files provided to the NAIF team by Alex Konopliv of the NEAR Radio Science Team. The models and input data used in the orbit determination process that produced the NIO files are summarized in the Appendix 1 of these comments. The Appendix 2 of these comments list the s/c maneuver times. The naming convention for the original SPK files was: p_near_YYYY_MM_DD_x.bsp where the designation refers to: YYYY_MM_DD file coverage start date; _x the file version; The complete list of SPK files the data from which have been included into this file is provided in the Appendix 3 of these comments. Contacts -------------------------------------------------------- If you have any questions regarding this data contact Boris V. Semenov, NAIF/JPL, +1 818 354-8136, bsemenov@spice.jpl.nasa.gov or: Alexander S. Konopliv +1 818 354-6105 Alexander.S.Konopliv@jpl.nasa.gov Appendix 1: Model and Input Data Description =========================================================================== The following description of the models and input data was provided by Alex Konopliv: ---------------------------------------------------------------- NEAR15A is a 15th degree and order model obtained from radiometric tracking (Doppler and range data) and landmark tracking of the NEAR spacecraft in orbit about Eros. The gravity model includes data from the entire mission beginning with orbit insertion on Feb. 14, 2000 and ending with the first descent maneuver for landing on Feb. 12, 2001. Some details describing this model are: The spherical harmonic coefficients are fully normalized. The associated GM = 4.46275E-04 The reference radius = 16.0 km The Eros-fixed reference frame is given by the J2000 pole and prime meridian: Right ascension = 11.363 degrees Declination = 17.232 degrees Prime Meridian = 326.08 degrees Rotation rate = 1639.389232 degrees/day Summary of data arcs in NEAR15A solution: Begin time Length Orbit Period Inclination (days) (km x km) (days) (asteroid equ.) ------------------------------------------------------------ 14-FEB-2000 10 366 x 324 21.8 35 24-FEB-2000 8 365 x 204 16.5 34 03-MAR-2000 29 209 x 200 10.0 38 02-APR-2000 10 210 x 100 6.6 56 11-APR-2000 11 101 x 99 3.4 60 22-APR-2000 8 101 x 50 2.2 65 30-APR-2000 24 52 x 49 1.2 90 24-MAY-2000 21 " " " 14-JUN-2000 23 " " " 07-JUL-2000 7 51 x 35 1.0 90 14-JUL-2000 10 40 x 35 0.7 90 24-JUL-2000 7 56 x 36 1.0 90 31-JUL-2000 8 52 x 49 1.2 90 08-AUG-2000 18 52 x 49 1.2 105 26-AUG-2000 10 102 x 49 2.3 113 05-SEP-2000 15 103 x 100 3.5 115 20-SEP-2000 10 " " " 30-SEP-2000 7 " " " 07-OCT-2000 6 " " " 13-OCT-2000 7 98 x 50 2.2 131 20-OCT-2000 5 52 x 50 1.2 133 25-OCT-2000 1 64 x 19 0.7 135 26-OCT-2000 8 203 x 64 5.3 144 03-NOV-2000 12 197 x 194 10.0 147 15-NOV-2000 14 " " " 29-NOV-2000 8 " " " 07-DEC-2000 6 193 x 34 4.2 178 13-DEC-2000 14 38 x 34 0.7 178 27-DEC-2000 13 " " " 09-JAN-2001 15 " " " 24-JAN-2001 4 36 x 22 0.6 178 28-JAN-2001 1 37 x 20 0.6 179 28-JAN-2001(b) 5 36 x 35 0.7 179 02-FEB-2001 4 " " " 06-FEB-2001 6 " " " Observations for the gravity field consist of Doppler and range measurements from Deep Space Network (DSN) tracking and landmark observables from the camera images of the asteroid Eros. The count time for the Doppler observations is 60 seconds. The typical accuracy for the Doppler is 0.03 mm/s for the 60 second sample time. The range accuracy is about 3 meters and is limited by the station calibration accuracy. The actual rms scatter is less than 0.5 meters in spacecraft position. The camera images are used to generate landmark observations. For each landmark we basically have two inertial angle measurements of a crater center. The two directions on the image are called line and pixel. Each image may be used to generate anywhere from 1 to 40 landmark observation pairs (line,pixel) with the average being about 6. The total number of landmarks (or craters) used for optical navigation is 1554. The measurement noise is about one pixel in both directions. The smaller landmark positions on Eros are determined to several meter accuracy. Summary of the number of observations for each arc: Begin time Doppler Range Landmark pairs ------------------------------------------------------------ 14-FEB-2000 7975 2126 4506 24-FEB-2000 6877 1456 2987 03-MAR-2000 19843 7578 9972 02-APR-2000 7385 1819 8303 11-APR-2000 7688 2450 2913 22-APR-2000 6852 1731 1497 30-APR-2000 21976 5410 3539 24-MAY-2000 20326 5514 4854 14-JUN-2000 22902 4414 8645 07-JUL-2000 6640 380 1666 14-JUL-2000 12757 1490 1371 24-JUL-2000 7906 600 2255 31-JUL-2000 9671 1757 2812 08-AUG-2000 19051 2934 4995 26-AUG-2000 10772 2172 5589 05-SEP-2000 12157 3288 7393 20-SEP-2000 6529 2007 5754 30-SEP-2000 4557 1588 6372 07-OCT-2000 4329 693 4716 13-OCT-2000 8156 1572 4901 20-OCT-2000 5355 1001 1037 25-OCT-2000 541 164 270 26-OCT-2000 6699 2164 3553 03-NOV-2000 12032 3128 4759 15-NOV-2000 10497 3249 4782 29-NOV-2000 6745 1670 2585 07-DEC-2000 5660 1008 2645 13-DEC-2000 8460 2584 3024 27-DEC-2000 9321 3422 2911 09-JAN-2001 10090 2892 3517 24-JAN-2001 3187 349 904 28-JAN-2001 552 0 177 28-JAN-2001(b) 3691 478 771 02-FEB-2001 4000 195 618 06-FEB-2001 6438 897 1000 Each Landmark pair consists of one line and one pixel measurement. Total Doppler observations = 317,617 Total Range observations = 74,180 Total Landmark pixel observations = 127,593 Total Landmark line observations = 127,593 ---------------------------------------------------------------- Appendix 2: Maneuver Start Times Table =========================================================================== The following maneuver times table was provided by Alex Konopliv: Maneuv ET Time UTC Time DOY ------ ------------------------ -------------- ----- OIM 14-FEB-2000 15:34:09.183 (15:33:05 UTC) 045.6 OCM-1 24-FEB-2000 17:01:04.185 (17:00:00 UTC) 055.7 OCM-2 03-MAR-2000 18:01:04.185 (18:00:00 UTC) 063.8 MCM-1 15-MAR-2000 19:59:04.185 (19:58:00 UTC) 075.8 MCM-2 23-MAR-2000 15:21:04.200 (15:20:00 UTC) 083.6 OCM-3 02-APR-2000 02:04:24.186 (02:03:20 UTC) 093.1 OCM-4 11-APR-2000 21:21:04.186 (21:20:00 UTC) 102.9 OCM-5 22-APR-2000 17:51:04.186 (17:50:00 UTC) 113.7 OCM-6 30-APR-2000 16:16:04.186 (16:15:00 UTC) 121.7 MCM-3 10-MAY-2000 14:01:04.185 (14:00:00 UTC) 131.6 MCM-4 17-MAY-2000 13:01:04.185 (13:00:00 UTC) 138.5 MCM-5 24-MAY-2000 13:01:04.185 (13:00:00 UTC) 145.5 MCM-6 31-MAY-2000 16:01:04.185 (16:00:00 UTC) 152.7 MCM-7 07-JUN-2000 16:01:04.185 (16:00:00 UTC) 159.7 MCM-8 14-JUN-2000 16:01:04.185 (16:00:00 UTC) 166.7 MCM-9 21-JUN-2000 16:01:04.185 (16:00:00 UTC) 173.7 MCM-10 28-JUN-2000 16:01:04.185 (16:00:00 UTC) 180.7 OCM-7 07-JUL-2000 18:01:04.185 (18:00:00 UTC) 189.8 OCM-8 14-JUL-2000 03:01:04.185 (03:00:00 UTC) 196.1 OCM-9 24-JUL-2000 17:01:04.185 (17:00:00 UTC) 206.7 OCM-10 31-JUL-2000 20:01:04.184 (20:00:00 UTC) 213.8 OCM-11 08-AUG-2000 23:26:04.183 (23:25:00 UTC) 222.0 OCM-12 26-AUG-2000 23:26:04.186 (23:25:00 UTC) 240.0 OCM-13 05-SEP-2000 23:01:04.186 (23:00:00 UTC) 250.0 MCM-12 20-SEP-2000 17:01:04.185 (17:00:00 UTC) 264.7 OCM-14 13-OCT-2000 05:46:04.182 (05:45:00 UTC) 287.2 OCM-15 20-OCT-2000 21:41:04.182 (21:40:00 UTC) 294.9 OCM-16 25-OCT-2000 22:11:04.182 (22:10:00 UTC) 299.9 OCM-17 26-OCT-2000 17:41:04.182 (17:40:00 UTC) 300.7 OCM-18 03-NOV-2000 03:01:04.182 (03:00:00 UTC) 308.1 MCM-13 15-NOV-2000 20:01:04.183 (20:00:00 UTC) 320.8 MCM-14 29-NOV-2000 17:31:04.183 (17:30:00 UTC) 334.7 OCM-19 07-DEC-2000 15:21:04.183 (15:20:00 UTC) 342.6 OCM-20 13-DEC-2000 20:16:04.183 (20:15:00 UTC) 348.8 MCM-15 27-DEC-2000 19:26:04.183 (19:25:00 UTC) 362.8 MCM-16 09-JAN-2001 18:42:44.184 (18:41:40 UTC) 9.8 OCM-21 24-JAN-2001 16:06:04.185 (16:05:00 UTC) 24.7 OCM-22 28-JAN-2001 01:26:04.185 (01:25:00 UTC) 28.1 OCM-23 28-JAN-2001 18:06:04.185 (18:05:00 UTC) 28.8 OCM-24 02-FEB-2001 08:52:04.185 (08:51:00 UTC) 33.4 OCM-25 06-FEB-2001 17:45:00.000 (17:43:56 UTC) 37.7 EMM-1 12-FEB-2001 15:15:00.000 (15:13:56 UTC) 43.63 EMM-2 12-FEB-2001 18:59:56.000 (18:58:52 UTC) 43.79 EMM-3 12-FEB-2001 19:15:17.000 (19:14:13 UTC) 43.80 EMM-4 12-FEB-2001 19:31:17.000 (19:30:13 UTC) 43.81 Appendix 3: Original SPK Files =========================================================================== The data from the following original files was included into this file (the fourth column contain the ID of the maneuver which occurred at the Stop Time of the trajectory segment): Original SPK File Start Time (ET) Stop Time (ET) Maneuver ------------------- ---------------- ---------------- -------- p_near_2000_02_14_b 2000-02-14-16:00 2000-02-24-17:01 OCM-1 p_near_2000_02_24_a 2000-02-24-17:15 2000-03-03-18:01 OCM-2 p_near_2000_03_03_a 2000-03-03-18:00 2000-04-02-02:04 OCM-3 p_near_2000_04_02_a 2000-04-02-02:15 2000-04-11-21:21 OCM-4 p_near_2000_04_11_a 2000-04-11-21:32 2000-04-22-17:51 OCM-5 p_near_2000_04_22_a 2000-04-22-18:00 2000-04-30-16:16 OCM-6 p_near_2000_04_30_a 2000-04-30-16:25 2000-05-17-15:00 p_near_2000_05_17_a 2000-05-17-15:00 2000-05-24-13:15 p_near_2000_05_24_a 2000-05-24-13:15 2000-06-07-17:00 p_near_2000_06_07_a 2000-06-07-17:00 2000-06-14-16:15 p_near_2000_06_14_a 2000-06-14-16:15 2000-07-07-18:01 OCM-7 p_near_2000_07_07_a 2000-07-07-18:10 2000-07-14-03:01 OCM-8 p_near_2000_07_14_a 2000-07-14-03:10 2000-07-24-17:01 OCM-9 p_near_2000_07_24_a 2000-07-24-17:10 2000-07-31-20:01 OCM-10 p_near_2000_07_31_a 2000-07-31-20:10 2000-08-08-23:26 OCM-11 p_near_2000_08_08_a 2000-08-08-23:35 2000-08-26-23:26 OCM-12 p_near_2000_08_26_a 2000-08-26-23:35 2000-09-05-23:01 OCM-13 p_near_2000_09_05_a 2000-09-05-23:10 2000-09-20-17:20 p_near_2000_09_20_a 2000-09-20-17:20 2000-09-30-17:00 p_near_2000_09_30_a 2000-09-30-17:00 2000-10-07-17:00 p_near_2000_10_07_a 2000-10-07-17:00 2000-10-13-05:46 OCM-14 p_near_2000_10_13_a 2000-10-13-06:00 2000-10-20-21:41 OCM-15 p_near_2000_10_20_a 2000-10-20-21:50 2000-10-25-22:11 OCM-16 p_near_2000_10_25_a 2000-10-25-22:20 2000-10-26-17:41 OCM-17 p_near_2000_10_26_a 2000-10-26-17:50 2000-11-03-03:01 OCM-18 p_near_2000_11_03_a 2000-11-03-03:10 2000-11-15-20:10 p_near_2000_11_15_a 2000-11-15-20:10 2000-11-29-17:40 p_near_2000_11_29_a 2000-11-29-17:40 2000-12-07-15:21 OCM-19 p_near_2000_12_07_a 2000-12-07-15:30 2000-12-13-20:16 OCM-20 p_near_2000_12_13_a 2000-12-13-20:25 2000-12-27-19:35 p_near_2000_12_27_a 2000-12-27-19:35 2001-01-09-18:51 p_near_2001_01_09_a 2001-01-09-18:51 2001-01-24-16:06 OCM-21 p_near_2001_01_24_a 2001-01-24-16:10 2001-01-28-01:26 OCM-22 p_near_2001_01_28_a 2001-01-28-01:30 2001-01-28-18:06 OCM-23 p_near_2001_01_28_b 2001-01-28-18:10 2001-02-02-08:52 OCM-24 p_near_2001_02_02_a 2001-02-02-08:55 2001-02-06-17:45 OCM-25 p_near_2001_02_06_a 2001-02-06-17:50 2001-02-12-15:15 EMM-1 Appendix 4: Segment Boundary Discontinuities =========================================================================== This table summarizes the discontinuities at the segment boundaries. BOUNDARY TIME (UTC) DOWNTRK INPLANE NORMAL ------------------------ ------- ------- ------- 2000-03-03T17:59:59.999 -0.014 0.160 -0.026 2000-05-17T14:58:55.814 -0.000 0.000 0.001 2000-05-24T13:13:55.814 -0.000 0.000 -0.002 2000-06-07T16:58:55.815 -0.005 -0.001 -0.001 2000-06-14T16:13:55.815 0.001 -0.000 -0.000 2000-09-20T17:18:55.817 0.007 -0.004 -0.000 2000-09-30T16:58:55.817 -0.000 -0.015 0.001 2000-10-07T16:58:55.817 -0.001 -0.009 -0.000 2000-11-15T20:08:55.817 0.044 -0.092 0.010 2000-11-29T17:38:55.816 0.060 -0.223 -0.030 2000-12-27T19:33:55.816 -0.000 0.001 0.000 2001-01-09T18:49:55.815 -0.003 0.002 0.000 The table consists of 4 columns. The first column contains the UTC time at which a segment boundary with discontinuity occurs. The next last three columns (2..4) contain view coordinate frame components in kilometers -- ``down track'' (this direction is parallel to the velocity vector), ``normal to plane'' (this direction is computed as cross product of position vector by velocity vector) and ``in plane'' (this direction is computed as a cross product of ``down track'' by ``normal to plane'') -- of the difference between the state vectors computed at that UTC time defining segment boundary at which a discontinuity exists. The pairs of segments and discontinuity times are determined using an algorithm that emulates the standard SPK loading priority -- ``last loaded segment takes precedence''. Therefore, the discontinuities summarized in the file are those which a user reading file would actually see. The difference components in the view coordinate frame were computed for each discontinuity using the following algorithm: -- A single state was computed from each pair of segment the J2000 frame at the time of discontinuity. -- For this pair of states, a position difference vector was computed by subtracting the state computed from the segment with higher priority from the state computed from segment with lower priority. Then, a frame transformation matrix rotating these difference vectors from J2000 to the view coordinate frame defined by the state obtained from the higher priority segment was computed, and the position difference vector was rotated to the view frame coordinates using this matrix. ********************************************************************************