MAVEN Reconstructed SPK, NAV Solution, 2016-01-01 to 2016-04-01, Version 1 =========================================================================== Created by Boris Semenov, NAIF/JPL, Tue May 10 16:39:25 PDT 2016 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 2441 through 2925): Start of Interval (ET) End of Interval (ET) -------------------------------- -------------------------------- 2016 JAN 01 00:01:08.183 2016 APR 01 01:01:08.185 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_02427-02459_rec_v1.bsp trj_orb_02458-02502_rec_v1.bsp trj_orb_02501-02532_rec_v1.bsp trj_orb_02531-02576_rec_v1.bsp trj_orb_02575-02614_rec_v1.bsp trj_orb_02613-02652_rec_v1.bsp trj_orb_02651-02690_rec_v1.bsp trj_orb_02689-02727_rec_v1.bsp trj_orb_02726-02764_rec_v1.bsp trj_orb_02763-02780_rec_v1.bsp trj_orb_02779-02836_rec_v1.bsp trj_orb_02835-02875_rec_v1.bsp trj_orb_02874-02914_rec_v1.bsp trj_orb_02913-02950_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_160101_160401_v1.bsp, km: # #ORBNUM BOUNDARY TIME (UTC) DOWNTRK INPLANE NORMAL #------- ----------------------- ------- ------- ------- 2444 2016-01-01T16:58:51.816 0.016 -0.008 -0.021 2448 2016-01-02T13:28:51.816 -0.011 -0.004 0.001 2452 2016-01-03T06:58:51.816 0.025 0.003 -0.014 2458 2016-01-04T10:43:51.815 0.004 0.002 0.000 2468 2016-01-06T05:09:51.815 0.005 -0.002 -0.007 2480 2016-01-08T11:23:51.815 -0.012 0.006 0.018 2485 2016-01-09T10:43:51.815 0.009 -0.004 -0.015 2492 2016-01-10T17:58:51.815 -0.011 0.006 0.022 2496 2016-01-11T11:58:51.815 0.003 -0.002 -0.007 2501 2016-01-12T11:13:51.815 0.002 -0.000 -0.004 2507 2016-01-13T15:33:51.815 -0.004 -0.001 0.003 2518 2016-01-15T15:13:51.815 0.004 -0.002 -0.011 2526 2016-01-17T02:58:51.815 -0.004 0.002 0.010 2531 2016-01-18T02:58:51.815 0.006 -0.001 -0.013 2538 2016-01-19T10:13:51.815 -0.002 0.001 0.006 2542 2016-01-20T04:58:51.815 -0.010 -0.001 0.020 2549 2016-01-21T10:58:51.815 0.004 -0.002 -0.012 2554 2016-01-22T10:28:51.815 0.023 -0.006 -0.075 2558 2016-01-23T03:58:51.815 -0.013 0.006 0.051 2569 2016-01-25T05:28:51.815 -0.008 0.003 0.035 2575 2016-01-26T10:08:51.815 -0.016 -0.004 0.048 2579 2016-01-27T02:58:51.815 0.033 -0.012 -0.184 2581 2016-01-27T11:58:51.815 -0.036 0.013 0.209 2584 2016-01-28T02:58:51.815 0.015 0.005 -0.044 2591 2016-01-29T10:48:51.815 0.002 0.001 -0.006 2595 2016-01-30T02:53:51.815 -0.003 0.001 0.023 2600 2016-01-31T02:48:51.815 0.013 0.003 -0.075 2607 2016-02-01T10:08:51.815 -0.004 -0.000 0.037 2613 2016-02-02T11:28:51.815 0.004 -0.002 -0.065 2622 2016-02-04T04:13:51.815 -0.001 0.000 0.020 2629 2016-02-05T11:43:51.815 -0.000 -0.000 0.001 2632 2016-02-06T02:38:51.815 -0.001 0.000 -0.151 2638 2016-02-07T04:48:51.815 0.008 -0.002 0.275 2645 2016-02-08T11:33:51.815 -0.004 0.002 -0.064 2651 2016-02-09T16:58:51.815 0.001 0.000 0.007 2654 2016-02-10T05:58:51.814 -0.009 -0.002 -0.085 2659 2016-02-11T03:58:51.814 0.001 -0.000 0.008 2667 2016-02-12T16:58:51.814 0.009 0.003 0.043 2675 2016-02-14T05:08:51.814 -0.007 -0.003 -0.026 2680 2016-02-15T03:43:51.814 0.004 0.002 0.013 2689 2016-02-16T19:58:51.814 0.002 0.001 0.005 2696 2016-02-18T03:58:51.814 -0.010 -0.005 -0.018 2705 2016-02-19T20:08:51.814 0.012 0.005 0.033 2709 2016-02-20T11:58:51.814 -0.010 0.005 -0.031 2715 2016-02-21T15:58:51.814 0.010 -0.002 0.033 2717 2016-02-22T02:18:51.814 -0.029 -0.013 -0.060 2721 2016-02-22T17:58:51.814 0.002 -0.001 0.006 2726 2016-02-23T17:28:51.814 -0.021 0.003 -0.060 2734 2016-02-25T04:28:51.814 0.003 -0.002 0.007 2742 2016-02-26T17:28:51.814 -0.022 0.004 -0.053 2748 2016-02-27T19:13:51.814 0.005 -0.002 0.005 2753 2016-02-28T17:43:51.814 0.035 -0.018 0.032 2757 2016-02-29T13:48:51.814 -0.061 -0.014 -0.124 2763 2016-03-01T14:53:51.814 -0.009 0.005 -0.011 2768 2016-03-02T14:08:51.814 0.024 -0.007 0.044 2770 2016-03-03T01:48:51.814 -0.030 -0.011 0.029 2779 2016-03-04T16:58:51.814 -0.067 -0.020 -0.114 2789 2016-03-06T11:58:51.814 0.025 -0.013 0.024 2795 2016-03-07T15:58:51.814 0.056 -0.010 0.087 2800 2016-03-08T15:28:51.814 -0.063 -0.019 -0.096 2808 2016-03-10T03:28:51.814 0.029 0.009 0.042 2817 2016-03-11T17:58:51.814 0.005 -0.003 0.004 2820 2016-03-12T09:58:51.814 0.023 0.011 0.027 2826 2016-03-13T11:58:51.814 -0.066 -0.006 -0.086 2832 2016-03-14T14:58:51.814 -0.019 -0.002 -0.024 2835 2016-03-15T05:30:51.814 -0.003 -0.001 -0.003 2840 2016-03-16T01:28:51.814 -0.064 0.032 -0.041 2845 2016-03-17T01:13:51.814 0.045 0.000 0.052 2847 2016-03-17T09:58:51.814 0.007 -0.001 0.008 2853 2016-03-18T14:28:51.814 0.014 0.007 0.014 2858 2016-03-19T10:23:51.814 -0.018 0.009 -0.009 2863 2016-03-20T09:23:51.814 0.078 -0.026 0.064 2868 2016-03-21T08:18:51.814 -0.026 0.004 -0.023 2874 2016-03-22T12:48:51.814 0.034 0.017 0.032 2879 2016-03-23T08:28:51.814 -0.062 0.032 -0.002 2883 2016-03-24T02:58:51.814 -0.003 0.001 -0.002 2890 2016-03-25T09:38:51.814 0.019 -0.009 -0.008 2900 2016-03-27T08:28:51.814 0.018 0.002 0.015 2907 2016-03-28T13:58:51.814 -0.025 0.011 0.011 2913 2016-03-29T18:08:51.814 -0.099 0.025 -0.056 2920 2016-03-31T00:28:51.814 -0.005 0.002 0.001 End of comments.