MAVEN Reconstructed SPK, NAV Solution, 2023-07-01 to 2023-10-01, Version 1 =========================================================================== Created by Boris Semenov, NAIF/JPL, Sat Nov 4 08:54:22 PDT 2023 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 19104 through 19708): Start of Interval (ET) End of Interval (ET) -------------------------------- -------------------------------- 2023 JUL 01 00:01:09.184 2023 OCT 01 01:01:09.182 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_19080-19130_rec_v1.bsp trj_orb_19129-19167_rec_v1.bsp trj_orb_19147-19213_rec_v1.bsp trj_orb_19212-19260_rec_v1.bsp trj_orb_19259-19289_rec_v1.bsp trj_orb_19288-19351_rec_v1.bsp trj_orb_19350-19400_rec_v1.bsp trj_orb_19399-19447_rec_v1.bsp trj_orb_19446-19491_rec_v1.bsp trj_orb_19490-19541_rec_v1.bsp trj_orb_19540-19581_rec_v1.bsp trj_orb_19580-19630_rec_v1.bsp trj_orb_19629-19673_rec_v1.bsp trj_orb_19672-19718_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_230701_231001_v1.bsp, km: # #ORBNUM BOUNDARY TIME (UTC) DOWNTRK INPLANE NORMAL #------- ----------------------- ------- ------- ------- 19117 2023-07-03T02:18:50.815 -0.000 0.000 0.000 19129 2023-07-04T21:55:50.815 -0.002 0.000 0.002 19142 2023-07-06T22:40:50.816 -0.002 0.001 -0.001 19147 2023-07-07T16:28:50.816 -0.012 0.005 0.001 19167 2023-07-10T18:58:50.816 -0.022 -0.006 -0.012 19191 2023-07-14T09:51:50.816 -0.005 0.000 -0.001 19206 2023-07-16T15:10:50.816 -0.007 0.001 0.002 19212 2023-07-17T15:39:50.816 -0.019 -0.007 -0.007 19228 2023-07-19T23:43:50.816 0.015 -0.005 -0.004 19245 2023-07-22T14:13:50.816 -0.007 0.003 0.000 19253 2023-07-23T19:22:50.816 0.004 -0.002 -0.000 19259 2023-07-24T17:18:50.816 0.006 -0.002 -0.000 19271 2023-07-26T14:33:50.816 0.001 0.000 0.000 19288 2023-07-29T04:03:50.816 -0.033 0.003 -0.006 19304 2023-07-31T13:52:50.816 0.011 -0.004 0.002 19312 2023-08-01T18:08:50.816 0.008 -0.000 -0.001 19320 2023-08-03T01:13:50.816 -0.008 -0.000 -0.001 19326 2023-08-03T23:13:50.816 0.012 0.001 0.002 19337 2023-08-05T14:58:50.816 -0.045 0.006 -0.011 19345 2023-08-06T19:07:05.816 0.007 -0.002 0.001 19350 2023-08-07T13:52:50.816 -0.016 0.006 -0.005 19359 2023-08-08T23:22:50.816 0.019 -0.002 0.005 19376 2023-08-11T12:47:50.816 -0.019 0.007 -0.008 19389 2023-08-13T11:38:50.817 0.000 -0.000 0.000 19399 2023-08-15T01:27:50.817 -0.025 0.002 -0.010 19409 2023-08-16T13:52:50.817 -0.033 0.004 -0.015 19422 2023-08-18T13:22:50.817 0.007 -0.001 0.004 19429 2023-08-19T14:13:50.817 0.015 -0.005 0.010 19446 2023-08-22T03:53:50.817 0.001 -0.000 0.000 19454 2023-08-23T09:18:50.817 -0.039 0.016 -0.029 19468 2023-08-25T13:13:50.817 0.049 -0.007 0.038 19483 2023-08-27T18:43:50.817 0.022 -0.005 0.001 19490 2023-08-28T20:13:50.817 0.027 -0.006 -0.004 19509 2023-08-31T18:58:50.817 0.032 -0.004 0.034 19524 2023-09-03T01:58:50.817 -0.005 -0.000 -0.006 19529 2023-09-03T18:50:50.817 -0.017 0.006 -0.011 19540 2023-09-05T11:43:50.817 0.002 -0.001 0.003 19551 2023-09-07T04:03:50.817 0.000 -0.000 0.000 19560 2023-09-08T13:23:50.817 0.008 0.000 0.012 19570 2023-09-10T02:03:50.817 0.006 0.001 0.009 19580 2023-09-11T13:00:50.817 0.005 -0.002 0.004 19589 2023-09-12T22:48:50.817 -0.007 0.001 -0.016 19599 2023-09-14T11:58:50.817 0.009 0.001 0.019 19617 2023-09-17T05:13:50.817 -0.005 0.000 -0.016 19629 2023-09-18T23:50:50.817 0.003 -0.001 0.004 19645 2023-09-21T10:14:50.817 0.001 -0.000 0.002 19656 2023-09-23T02:53:50.817 -0.000 0.000 -0.003 19672 2023-09-25T12:41:50.817 0.003 -0.001 0.004 19682 2023-09-27T01:38:50.817 -0.001 0.000 -0.011 19698 2023-09-29T11:28:50.817 -0.000 -0.000 0.006 19704 2023-09-30T09:03:50.817 -0.000 0.000 -0.009 End of comments.