MAVEN Reconstructed SPK, NAV Solution, 2020-10-01 to 2021-01-01, Version 1 =========================================================================== Created by Boris Semenov, NAIF/JPL, Thu Jan 28 08:20:54 PST 2021 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 12458 through 13069): Start of Interval (ET) End of Interval (ET) -------------------------------- -------------------------------- 2020 OCT 01 00:01:09.182 2021 JAN 01 01:01:09.183 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_12448-12495_rec_v1.bsp trj_orb_12494-12542_rec_v1.bsp trj_orb_12541-12584_rec_v1.bsp trj_orb_12583-12631_rec_v1.bsp trj_orb_12630-12673_rec_v1.bsp trj_orb_12672-12719_rec_v1.bsp trj_orb_12718-12751_rec_v1.bsp trj_orb_12750-12824_rec_v1.bsp trj_orb_12823-12857_rec_v1.bsp trj_orb_12856-12898_rec_v1.bsp trj_orb_12897-12957_rec_v1.bsp trj_orb_12956-13009_rec_v1.bsp trj_orb_13008-13056_rec_v1.bsp trj_orb_13055-13085_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_201001_210101_v1.bsp, km: # #ORBNUM BOUNDARY TIME (UTC) DOWNTRK INPLANE NORMAL #------- ----------------------- ------- ------- ------- 12459 2020-10-01T05:15:50.817 -0.002 0.001 0.002 12470 2020-10-02T20:58:50.817 0.011 -0.004 -0.011 12479 2020-10-04T05:53:50.817 0.001 -0.000 -0.001 12486 2020-10-05T06:43:50.817 -0.002 0.001 0.002 12494 2020-10-06T12:06:27.817 -0.001 0.000 0.002 12499 2020-10-07T05:11:50.817 -0.003 0.001 -0.001 12506 2020-10-08T06:49:17.817 0.003 -0.001 -0.003 12514 2020-10-09T11:41:17.817 0.008 -0.003 -0.009 12518 2020-10-10T02:48:50.817 -0.003 0.000 0.005 12526 2020-10-11T07:13:50.817 -0.012 0.003 0.019 12534 2020-10-12T11:58:50.817 0.005 -0.002 -0.007 12541 2020-10-13T13:43:50.817 -0.002 0.000 0.005 12552 2020-10-15T04:58:50.817 -0.002 0.001 0.003 12563 2020-10-16T20:28:50.817 0.004 -0.001 -0.005 12572 2020-10-18T06:20:50.817 0.004 0.001 -0.010 12583 2020-10-19T20:43:50.817 0.006 -0.002 -0.010 12590 2020-10-20T22:08:50.817 -0.001 0.000 0.001 12597 2020-10-21T23:18:50.817 -0.004 0.001 0.007 12607 2020-10-23T11:56:32.817 0.005 0.000 -0.015 12617 2020-10-24T23:36:30.817 -0.006 0.001 0.013 12623 2020-10-25T22:41:40.817 0.005 0.002 -0.014 12630 2020-10-26T22:16:50.817 -0.006 0.002 0.012 12637 2020-10-27T23:30:50.817 0.002 -0.001 -0.004 12645 2020-10-29T04:30:50.817 -0.001 0.000 0.001 12659 2020-10-31T06:58:50.817 -0.002 0.000 0.005 12665 2020-11-01T04:33:50.817 0.005 -0.001 -0.012 12672 2020-11-02T05:58:50.817 0.002 -0.000 -0.006 12684 2020-11-04T01:13:50.817 0.000 0.000 -0.001 12696 2020-11-05T21:13:50.817 0.000 0.000 -0.001 12703 2020-11-06T21:53:50.817 -0.002 0.000 0.008 12718 2020-11-09T05:08:50.817 -0.002 -0.001 0.015 12727 2020-11-10T12:20:29.817 0.000 -0.000 -0.002 12733 2020-11-11T10:10:26.817 0.000 -0.000 -0.001 12740 2020-11-12T11:15:33.817 0.000 0.000 0.000 12745 2020-11-13T05:18:05.817 -0.001 0.000 0.011 12750 2020-11-13T23:18:50.817 0.001 0.000 -0.004 12766 2020-11-16T10:18:50.817 -0.000 0.000 0.002 12768 2020-11-16T16:58:50.817 0.001 0.000 -0.059 12776 2020-11-17T21:18:50.817 0.000 0.000 0.042 12789 2020-11-19T20:58:50.817 0.000 0.000 0.015 12799 2020-11-21T08:16:50.817 0.001 0.000 0.004 12809 2020-11-22T20:24:50.817 -0.001 -0.000 -0.004 12823 2020-11-24T22:58:50.817 0.001 -0.000 0.005 12832 2020-11-26T07:28:50.817 -0.001 -0.000 -0.003 12842 2020-11-27T17:38:50.816 -0.001 0.000 0.003 12850 2020-11-29T00:31:01.816 -0.003 -0.000 -0.008 12856 2020-11-29T20:17:50.816 -0.001 0.000 0.005 12869 2020-12-01T19:33:50.816 -0.000 0.000 0.002 12878 2020-12-03T04:13:50.816 0.000 0.000 -0.000 12889 2020-12-04T21:23:50.816 -0.002 -0.000 -0.003 12897 2020-12-06T02:18:50.816 -0.000 -0.000 -0.001 12909 2020-12-07T21:32:50.816 -0.002 -0.000 -0.002 12916 2020-12-08T22:47:50.816 0.003 0.000 0.003 12922 2020-12-09T18:42:50.816 -0.001 0.000 0.003 12938 2020-12-12T04:28:50.816 -0.002 0.001 0.004 12948 2020-12-13T16:43:50.816 0.001 -0.000 -0.003 12956 2020-12-14T21:55:40.816 0.001 -0.000 -0.002 12962 2020-12-15T19:07:23.816 -0.001 0.000 0.003 12969 2020-12-16T20:21:33.816 0.001 -0.000 -0.002 12975 2020-12-17T18:49:50.816 -0.003 0.001 0.003 12984 2020-12-19T02:58:50.816 0.004 -0.001 -0.005 12995 2020-12-20T18:28:50.816 -0.003 0.001 0.004 13008 2020-12-22T19:09:50.816 0.002 0.001 0.002 13024 2020-12-25T02:39:50.816 0.003 -0.001 -0.004 13037 2020-12-27T01:48:50.816 -0.009 0.003 0.011 13048 2020-12-28T19:03:50.816 0.003 0.001 -0.000 13055 2020-12-29T19:24:50.816 -0.011 0.003 0.009 13068 2020-12-31T18:49:50.816 0.013 0.000 -0.006 End of comments.