MAVEN Reconstructed SPK, NAV Solution, 2020-04-01 to 2020-07-01, Version 1 =========================================================================== Created by Boris Semenov, NAIF/JPL, Wed Aug 5 11:31:53 PDT 2020 Objects in the Ephemeris -------------------------------------------------------- This SPK file contains ephemeris data for the Mars Atmosphere and Volatile Evolution Mission (MAVEN) spacecraft. The NAIF ID code for MAVEN is -202. Approximate Time Coverage -------------------------------------------------------- This file covers the following part of the orbital phase of the MAVEN mission (orbits 11238 through 11844): Start of Interval (ET) End of Interval (ET) -------------------------------- -------------------------------- 2020 APR 01 00:01:09.185 2020 JUL 01 01:01:09.184 Status -------------------------------------------------------- This file was created by merging regular reconstructed OD solution SPK files produced by the MAVEN NAV team during the orbital phase of the mission. This file was created by NAIF for archiving in the Planetary Data System (PDS). Pedigree -------------------------------------------------------- The original SPK files used to create this file contained only reconstructed trajectory. They were officially delivered to the MAVEN project data base by the MAVEN NAV team. The list of the original files data from which has been merged into this file is provided in Appendix 1 of these comments. Segment Boundary Discontinuities -------------------------------------------------------- This SPK file contains a large number of SPK segments that came from original individual SPK files. Although, each segment provides continuous trajectory within the interval that it covers, in general a position and velocity discontinuity exists at the boundary of the segment and the segments whose coverages immediately precede or follow it. The times and magnitudes of these discontinuities are provided in Appendix 2 of these comments. Usage -------------------------------------------------------- This file should be used together with DE430 planetary ephemeris and MAR097 satellite ephemeris since the original SPK files contained subsets of these particular ephemeris in them. Contacts -------------------------------------------------------- If you have questions regarding this data contact Boris V. Semenov (818)-354-8136 Boris.Semenov@jpl.nasa.gov Appendix 1: Original SPK List -------------------------------------------------------- The original SPK files, the data from which has been included into this file, are: trj_orb_11228-11282_rec_v1.bsp trj_orb_11281-11329_rec_v1.bsp trj_orb_11328-11375_rec_v1.bsp trj_orb_11374-11423_rec_v1.bsp trj_orb_11422-11468_rec_v1.bsp trj_orb_11467-11507_rec_v1.bsp trj_orb_11507-11563_rec_v1.bsp trj_orb_11562-11608_rec_v1.bsp trj_orb_11607-11656_rec_v1.bsp trj_orb_11655-11703_rec_v1.bsp trj_orb_11701-11748_rec_v1.bsp trj_orb_11747-11772_rec_v1.bsp trj_orb_11771-11843_rec_v1.bsp trj_orb_11842-11890_rec_v1.bsp Appendix 2: Segment Boundary Discontinuity Summary -------------------------------------------------------- This SPK file contains a large number of SPK segments that came from original individual SPK files. Although, each segment provides continuous trajectory within the interval that it covers, in general a position and velocity discontinuity exists at the boundary of the segment and the segments whose coverage immediately precede and follow it. The times and magnitudes of these discontinuities are provided in the table included in this Appendix. The top portion of the table contains the name of this SPK file. All descriptive lines in the top portion of the file start with the ``#'' character to allow direct plotting of the data in the freeware ``gnuplot'' application. The table consists of 5 columns. The first column is the orbit number within which a segment boundary with discontinuity occurs. The next column contains the UTC time of that segment boundary. The last three columns (3..5) contain view coordinate frame components -- ``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. The segment boundary discontinuities for this file are: # # Summary of discontinuities at segment boundaries for # SPK file ./maven_orb_rec_200401_200701_v1.bsp, km: # #ORBNUM BOUNDARY TIME (UTC) DOWNTRK INPLANE NORMAL #------- ----------------------- ------- ------- ------- 11241 2020-04-01T13:50:50.814 0.057 0.004 -0.018 11247 2020-04-02T11:45:50.814 -0.048 -0.010 0.014 11254 2020-04-03T12:23:50.814 -0.001 0.000 0.000 11265 2020-04-05T04:43:50.814 -0.066 -0.016 0.014 11273 2020-04-06T07:58:50.814 0.028 -0.012 -0.001 11281 2020-04-07T12:42:13.814 0.026 -0.010 0.000 11294 2020-04-09T13:29:44.814 -0.039 -0.011 0.004 11308 2020-04-11T14:28:50.814 -0.003 -0.001 0.000 11316 2020-04-12T20:18:50.814 -0.004 -0.000 0.000 11328 2020-04-14T14:03:50.814 0.010 -0.003 -0.001 11346 2020-04-17T07:09:50.814 -0.006 0.003 0.001 11355 2020-04-18T15:58:50.814 -0.033 0.012 0.001 11363 2020-04-19T20:28:50.814 -0.010 0.004 0.001 11374 2020-04-21T11:58:50.814 -0.014 0.005 0.003 11383 2020-04-22T20:38:50.814 0.012 -0.005 -0.002 11394 2020-04-24T12:18:50.814 0.019 -0.008 -0.003 11402 2020-04-25T16:33:50.814 -0.006 0.001 0.002 11409 2020-04-26T18:10:50.814 -0.013 0.005 0.004 11414 2020-04-27T12:08:50.814 0.005 -0.002 -0.002 11422 2020-04-28T18:23:44.814 0.012 0.000 0.003 11431 2020-04-30T03:33:14.814 -0.031 -0.012 -0.016 11445 2020-05-02T04:58:50.814 0.030 -0.003 0.006 11456 2020-05-03T21:05:50.814 -0.018 -0.002 -0.008 11467 2020-05-05T11:13:50.814 -0.005 0.002 0.003 11475 2020-05-06T15:58:50.814 -0.001 0.001 0.001 11480 2020-05-07T10:41:50.814 0.021 -0.006 -0.001 11489 2020-05-08T19:13:50.814 -0.015 0.003 -0.000 11499 2020-05-10T07:53:50.814 -0.002 -0.000 -0.001 11507 2020-05-11T11:15:50.814 -0.007 0.003 0.006 11514 2020-05-12T12:02:50.814 -0.003 0.000 0.002 11519 2020-05-13T06:26:50.814 0.006 -0.003 -0.007 11528 2020-05-14T16:22:50.814 -0.006 -0.001 -0.003 11534 2020-05-15T12:28:50.814 -0.005 0.002 0.006 11541 2020-05-16T13:58:50.814 -0.001 0.000 0.001 11549 2020-05-17T19:38:50.814 -0.000 -0.000 -0.000 11562 2020-05-19T17:58:50.814 -0.002 0.001 0.001 11568 2020-05-20T15:58:50.814 -0.006 0.001 0.000 11582 2020-05-22T17:11:17.814 0.006 -0.002 -0.010 11592 2020-05-24T06:17:00.814 -0.008 0.001 0.002 11595 2020-05-24T16:25:26.814 0.003 -0.001 -0.005 11607 2020-05-26T11:28:50.814 0.001 -0.000 -0.001 11621 2020-05-28T16:03:50.815 -0.001 -0.001 -0.003 11628 2020-05-29T14:58:50.815 0.001 -0.000 -0.003 11638 2020-05-31T02:54:50.815 -0.000 0.000 0.001 11644 2020-06-01T02:28:50.815 0.002 0.001 0.004 11655 2020-06-02T18:23:50.815 0.002 0.001 0.005 11665 2020-06-04T06:13:50.815 -0.001 0.000 -0.002 11676 2020-06-05T19:48:50.815 -0.000 0.000 0.001 11684 2020-06-07T02:43:50.815 0.000 0.000 0.002 11695 2020-06-08T16:55:50.815 0.001 -0.000 -0.008 11701 2020-06-09T16:03:41.815 0.001 0.000 0.005 11715 2020-06-11T16:17:46.815 0.000 -0.000 -0.001 11722 2020-06-12T17:17:06.815 0.000 -0.000 -0.021 11727 2020-06-13T11:58:50.815 0.001 -0.000 0.044 11734 2020-06-14T12:58:50.815 -0.000 -0.000 -0.008 11740 2020-06-15T10:28:50.815 -0.001 0.000 -0.021 11747 2020-06-16T11:18:50.815 -0.000 0.000 -0.004 11751 2020-06-17T01:48:50.815 -0.001 0.000 -0.011 11762 2020-06-18T17:16:50.815 -0.000 0.000 -0.001 11771 2020-06-20T01:38:50.815 -0.001 0.000 -0.003 11785 2020-06-22T04:08:50.815 -0.001 0.000 -0.003 11788 2020-06-22T14:54:50.815 -0.002 0.001 -0.008 11799 2020-06-24T06:25:50.815 0.002 -0.001 0.005 11809 2020-06-25T18:24:50.815 0.000 -0.000 0.001 11818 2020-06-27T03:08:50.815 -0.009 0.003 -0.027 11829 2020-06-28T18:28:50.815 -0.000 -0.000 -0.000 11834 2020-06-29T12:28:50.815 0.006 -0.003 0.014 11842 2020-06-30T17:28:50.815 0.010 -0.004 0.024 End of comments.