MAVEN Reconstructed SPK, NAV Solution, 2019-10-01 to 2020-01-01, Version 1 =========================================================================== Created by Boris Semenov, NAIF/JPL, Thu Feb 6 16:49:59 PST 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 10024 through 10633): Start of Interval (ET) End of Interval (ET) -------------------------------- -------------------------------- 2019 OCT 01 00:01:09.182 2020 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_09981-10028_rec_v1.bsp trj_orb_10027-10074_rec_v1.bsp trj_orb_10073-10094_rec_v1.bsp trj_orb_10093-10167_rec_v1.bsp trj_orb_10166-10191_rec_v1.bsp trj_orb_10190-10260_rec_v1.bsp trj_orb_10259-10313_rec_v1.bsp trj_orb_10312-10353_rec_v1.bsp trj_orb_10352-10384_rec_v1.bsp trj_orb_10383-10424_rec_v1.bsp trj_orb_10423-10493_rec_v1.bsp trj_orb_10492-10539_rec_v1.bsp trj_orb_10538-10560_rec_v1.bsp trj_orb_10559-10606_rec_v1.bsp trj_orb_10605-10658_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_191001_200101_v1.bsp, km: # #ORBNUM BOUNDARY TIME (UTC) DOWNTRK INPLANE NORMAL #------- ----------------------- ------- ------- ------- 10027 2019-10-01T14:33:50.817 -0.009 0.003 0.022 10038 2019-10-03T06:53:50.817 -0.014 0.005 0.048 10048 2019-10-04T18:28:50.817 -0.000 0.000 0.000 10058 2019-10-06T06:53:50.817 0.021 -0.007 -0.049 10066 2019-10-07T14:46:20.817 0.001 0.000 0.006 10073 2019-10-08T14:14:56.817 -0.010 0.002 0.056 10082 2019-10-09T21:54:50.817 0.010 -0.004 -0.032 10093 2019-10-11T14:09:39.817 0.005 -0.002 -0.048 10098 2019-10-12T07:58:50.817 0.003 0.001 -0.002 10108 2019-10-13T20:18:50.817 0.006 -0.002 -0.098 10120 2019-10-15T15:44:51.817 0.002 0.001 -0.128 10124 2019-10-16T06:39:44.817 0.002 -0.001 0.181 10140 2019-10-18T17:23:50.817 0.007 -0.000 0.113 10144 2019-10-19T06:38:50.817 0.005 -0.002 0.035 10155 2019-10-20T22:17:20.817 0.004 -0.001 0.009 10166 2019-10-22T13:55:50.817 -0.002 0.001 0.002 10175 2019-10-23T22:38:50.817 -0.000 -0.000 -0.000 10190 2019-10-26T06:38:50.817 -0.005 -0.001 -0.016 10201 2019-10-27T20:38:50.817 -0.006 0.002 -0.002 10212 2019-10-29T13:58:50.817 0.015 0.002 0.041 10221 2019-10-30T21:00:28.243 0.001 -0.000 0.000 10230 2019-11-01T06:29:00.620 0.007 -0.001 0.015 10240 2019-11-02T19:38:31.817 -0.023 -0.007 -0.044 10247 2019-11-03T19:54:19.817 0.026 -0.005 0.048 10259 2019-11-05T14:28:50.817 0.000 -0.000 -0.000 10274 2019-11-07T20:18:50.817 -0.005 0.001 0.006 10283 2019-11-09T06:27:50.817 -0.002 -0.001 -0.002 10290 2019-11-10T06:28:50.817 0.021 -0.008 0.000 10300 2019-11-11T19:32:50.817 -0.019 0.003 -0.021 10312 2019-11-13T14:39:55.817 -0.026 0.006 -0.023 10320 2019-11-14T19:33:53.817 -0.015 0.004 -0.012 10325 2019-11-15T13:44:43.817 -0.007 0.001 -0.006 10338 2019-11-17T13:43:22.688 0.056 0.017 0.054 10345 2019-11-18T13:47:55.817 0.007 -0.002 0.004 10352 2019-11-19T13:58:50.817 0.022 -0.003 -0.019 10361 2019-11-20T23:13:50.817 -0.005 0.002 -0.001 10373 2019-11-22T18:58:50.817 -0.011 0.003 -0.005 10376 2019-11-23T06:48:50.817 -0.018 -0.005 -0.013 10383 2019-11-24T06:58:50.817 -0.053 0.015 -0.017 10400 2019-11-26T19:26:50.817 0.000 -0.000 -0.000 10406 2019-11-27T17:19:50.817 0.026 -0.010 -0.009 10416 2019-11-29T06:22:50.816 0.022 -0.005 0.006 10423 2019-11-30T06:38:50.816 0.063 -0.021 -0.025 10431 2019-12-01T13:28:50.816 0.008 0.002 0.003 10445 2019-12-03T13:59:50.816 -0.028 0.007 0.010 10458 2019-12-05T13:32:50.816 0.001 -0.001 -0.000 10472 2019-12-07T18:18:50.816 0.001 0.001 0.000 10479 2019-12-08T18:18:50.816 0.030 -0.002 0.003 10485 2019-12-09T14:53:50.816 -0.034 0.014 0.005 10492 2019-12-10T18:28:50.816 0.012 0.005 0.002 10503 2019-12-12T08:43:50.816 -0.035 0.008 -0.001 10516 2019-12-14T06:53:50.816 0.034 -0.014 -0.002 10526 2019-12-15T19:13:50.816 0.012 -0.007 -0.000 10538 2019-12-17T15:53:50.816 0.041 0.006 -0.001 10545 2019-12-18T15:48:50.816 -0.030 0.011 -0.001 10552 2019-12-19T17:48:50.816 -0.000 0.000 0.000 10559 2019-12-20T18:43:50.816 0.013 -0.005 0.001 10584 2019-12-24T13:58:50.816 -0.047 0.003 0.003 10589 2019-12-25T07:13:50.816 0.036 -0.014 0.005 10605 2019-12-27T17:43:27.816 0.014 -0.003 0.000 10612 2019-12-28T18:03:29.816 -0.011 0.004 -0.004 10619 2019-12-29T19:22:42.816 -0.007 0.002 -0.002 10632 2019-12-31T19:25:29.816 0.015 -0.003 0.001 End of comments.