MAVEN Reconstructed SPK, NAV Solution, 2018-07-01 to 2018-10-01, Version 1 =========================================================================== Created by Boris Semenov, NAIF/JPL, Wed Nov 14 14:31:43 PST 2018 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 7305 through 7803): Start of Interval (ET) End of Interval (ET) -------------------------------- -------------------------------- 2018 JUL 01 00:01:09.184 2018 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_07277-07313_rec_v1.bsp trj_orb_07312-07356_rec_v1.bsp trj_orb_07355-07395_rec_v1.bsp trj_orb_07394-07431_rec_v1.bsp trj_orb_07430-07470_rec_v1.bsp trj_orb_07469-07508_rec_v1.bsp trj_orb_07507-07538_rec_v1.bsp trj_orb_07537-07584_rec_v1.bsp trj_orb_07583-07622_rec_v1.bsp trj_orb_07621-07654_rec_v1.bsp trj_orb_07653-07699_rec_v1.bsp trj_orb_07698-07728_rec_v1.bsp trj_orb_07727-07766_rec_v1.bsp trj_orb_07765-07808_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_180701_181001_v1.bsp, km: # #ORBNUM BOUNDARY TIME (UTC) DOWNTRK INPLANE NORMAL #------- ----------------------- ------- ------- ------- 7309 2018-07-01T23:10:45.815 -0.025 -0.005 -0.019 7312 2018-07-02T11:53:50.815 -0.021 0.002 -0.012 7319 2018-07-03T17:58:50.815 0.012 -0.006 -0.000 7326 2018-07-05T00:43:50.815 0.000 -0.000 -0.000 7334 2018-07-06T11:58:50.816 0.014 -0.005 -0.012 7347 2018-07-08T22:43:50.816 -0.017 0.007 -0.002 7355 2018-07-10T09:43:50.816 -0.028 0.014 0.012 7361 2018-07-11T11:58:50.816 -0.002 0.001 0.002 7367 2018-07-12T15:03:50.816 0.016 -0.008 -0.008 7371 2018-07-13T11:21:20.816 0.001 0.000 0.001 7378 2018-07-14T16:58:50.816 -0.004 0.001 -0.001 7385 2018-07-16T00:58:50.816 0.051 0.014 0.038 7394 2018-07-17T15:45:50.816 0.041 -0.012 0.003 7401 2018-07-18T22:10:50.816 0.007 -0.004 -0.004 7403 2018-07-19T09:10:50.816 -0.021 -0.008 -0.018 7412 2018-07-20T22:19:50.816 0.024 -0.006 -0.023 7414 2018-07-21T08:45:18.816 -0.007 0.002 -0.001 7420 2018-07-22T10:35:17.816 -0.014 0.007 0.009 7430 2018-07-24T08:53:50.816 -0.003 -0.001 -0.002 7437 2018-07-25T16:13:50.816 0.011 0.004 0.010 7448 2018-07-27T15:28:50.816 -0.007 0.002 0.001 7458 2018-07-29T11:58:50.816 0.002 -0.000 -0.000 7469 2018-07-31T11:28:50.816 -0.000 0.000 0.000 7473 2018-08-01T07:48:50.816 0.013 0.005 0.010 7480 2018-08-02T14:03:50.816 -0.021 -0.001 -0.004 7486 2018-08-03T14:58:50.816 0.005 -0.003 -0.006 7495 2018-08-05T09:58:50.816 -0.005 -0.002 -0.006 7501 2018-08-06T10:36:50.816 -0.014 0.003 0.004 7507 2018-08-07T13:01:20.816 0.007 -0.002 -0.003 7513 2018-08-08T14:15:52.816 -0.005 0.002 0.005 7517 2018-08-09T08:40:43.816 0.005 -0.002 -0.005 7525 2018-08-10T22:28:50.816 -0.001 -0.000 -0.001 7532 2018-08-12T05:28:50.816 0.003 0.002 0.003 7537 2018-08-13T03:18:50.817 0.006 0.002 0.003 7544 2018-08-14T10:23:50.817 0.000 0.000 0.000 7550 2018-08-15T13:03:50.817 0.001 0.001 0.001 7556 2018-08-16T13:58:50.817 0.003 -0.001 -0.002 7566 2018-08-18T10:30:27.817 -0.047 0.007 0.025 7571 2018-08-19T07:05:36.817 0.025 -0.010 -0.032 7583 2018-08-21T14:13:50.817 0.005 0.001 -0.001 7595 2018-08-23T19:23:50.817 -0.019 -0.003 0.003 7601 2018-08-24T21:25:50.817 0.030 -0.003 -0.020 7604 2018-08-25T10:08:50.817 -0.023 0.008 0.027 7613 2018-08-27T03:08:50.817 0.005 0.001 -0.001 7621 2018-08-28T12:28:50.817 -0.020 0.010 0.036 7629 2018-08-30T01:58:50.817 -0.005 -0.001 0.001 7631 2018-08-30T11:08:50.817 0.019 0.008 0.006 7639 2018-08-31T20:03:50.817 0.005 -0.002 -0.010 7647 2018-09-02T07:28:50.817 -0.007 0.003 0.014 7653 2018-09-03T10:38:50.817 -0.007 0.002 0.011 7659 2018-09-04T12:58:50.817 0.022 -0.009 -0.044 7662 2018-09-05T01:58:50.817 -0.011 0.005 0.023 7669 2018-09-06T11:21:50.817 -0.006 -0.003 -0.006 7680 2018-09-08T08:51:24.817 0.012 -0.006 -0.026 7685 2018-09-09T07:31:07.817 -0.030 0.014 0.076 7689 2018-09-10T01:27:50.817 0.024 -0.009 -0.058 7698 2018-09-11T19:01:50.817 -0.013 -0.006 -0.001 7702 2018-09-12T11:25:50.817 0.001 -0.000 -0.002 7705 2018-09-13T01:32:50.817 0.023 0.007 -0.018 7707 2018-09-13T10:16:50.817 -0.038 -0.011 0.037 7718 2018-09-15T11:03:50.817 0.011 0.004 -0.008 7727 2018-09-17T01:28:50.817 -0.011 0.002 0.033 7738 2018-09-19T01:43:50.817 0.009 -0.003 -0.036 7743 2018-09-20T01:32:50.817 -0.004 -0.002 0.002 7752 2018-09-21T17:46:50.817 0.001 0.000 0.002 7760 2018-09-23T02:58:50.817 0.006 -0.001 -0.028 7765 2018-09-24T01:58:50.817 0.005 0.001 -0.017 7774 2018-09-25T18:41:50.817 0.004 0.002 0.007 7785 2018-09-27T18:10:50.817 -0.011 -0.002 0.059 7793 2018-09-29T05:33:50.817 -0.030 -0.008 0.187 7799 2018-09-30T07:28:50.817 0.030 0.000 -0.322 End of comments.