MAVEN Reconstructed SPK, NAV Solution, 2017-10-01 to 2018-01-01, Version 1 =========================================================================== Created by Boris Semenov, NAIF/JPL, Thu Feb 8 18:17:54 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 5828 through 6329): Start of Interval (ET) End of Interval (ET) -------------------------------- -------------------------------- 2017 OCT 01 00:01:09.182 2018 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_05804-05838_rec_v1.bsp trj_orb_05837-05875_rec_v1.bsp trj_orb_05874-05908_rec_v1.bsp trj_orb_05907-05914_rec_v1.bsp trj_orb_05913-05919_rec_v1.bsp trj_orb_05918-05925_rec_v1.bsp trj_orb_05924-05930_rec_v1.bsp trj_orb_05929-05935_rec_v1.bsp trj_orb_05934-05941_rec_v1.bsp trj_orb_05940-05949_rec_v1.bsp trj_orb_05948-05957_rec_v1.bsp trj_orb_05956-05977_rec_v1.bsp trj_orb_05976-06028_rec_v1.bsp trj_orb_06027-06072_rec_v1.bsp trj_orb_06071-06110_rec_v1.bsp trj_orb_06109-06149_rec_v1.bsp trj_orb_06148-06188_rec_v1.bsp trj_orb_06187-06226_rec_v1.bsp trj_orb_06225-06243_rec_v1.bsp trj_orb_06242-06301_rec_v1.bsp trj_orb_06300-06334_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_171001_180101_v1.bsp, km: # #ORBNUM BOUNDARY TIME (UTC) DOWNTRK INPLANE NORMAL #------- ----------------------- ------- ------- ------- 5829 2017-10-01T08:28:50.817 0.011 0.001 -0.006 5837 2017-10-02T20:28:50.817 0.020 0.006 -0.021 5845 2017-10-04T06:28:50.817 -0.016 0.007 -0.011 5861 2017-10-07T05:43:50.817 -0.000 -0.000 -0.000 5870 2017-10-08T20:18:50.817 -0.003 0.001 -0.007 5874 2017-10-09T16:08:50.817 -0.024 -0.001 0.012 5880 2017-10-10T17:28:50.817 0.015 -0.007 0.029 5886 2017-10-11T21:28:50.817 -0.006 -0.001 0.004 5891 2017-10-12T20:03:46.817 0.003 0.001 -0.004 5897 2017-10-13T22:26:36.817 0.006 0.001 -0.006 5900 2017-10-14T11:50:06.817 -0.001 -0.000 0.000 5904 2017-10-15T05:37:36.817 -0.001 -0.000 0.001 5907 2017-10-15T16:58:50.817 -0.013 0.006 -0.051 5911 2017-10-16T10:38:50.817 -0.007 0.003 -0.029 5913 2017-10-16T21:33:50.817 -0.025 -0.007 0.042 5915 2017-10-17T06:23:50.817 0.030 0.009 -0.054 5918 2017-10-17T19:38:50.817 0.007 0.002 -0.014 5921 2017-10-18T08:48:50.817 0.002 0.000 -0.003 5924 2017-10-18T22:34:50.817 -0.013 -0.006 0.058 5927 2017-10-19T11:18:50.817 0.034 0.012 -0.090 5929 2017-10-19T20:08:50.817 0.031 0.012 -0.093 5932 2017-10-20T09:18:50.817 -0.034 -0.013 0.115 5934 2017-10-20T18:00:50.817 -0.065 -0.023 0.209 5937 2017-10-21T07:13:50.817 -0.006 -0.002 0.025 5940 2017-10-21T20:13:50.817 0.019 0.007 -0.075 5941 2017-10-22T00:33:50.817 -0.043 -0.016 0.168 5945 2017-10-22T15:26:50.817 -0.007 0.003 -0.076 5947 2017-10-23T02:43:50.817 -0.008 -0.003 0.040 5948 2017-10-23T07:28:50.817 0.007 0.003 -0.069 5952 2017-10-24T00:28:50.817 -0.020 -0.008 0.133 5956 2017-10-24T17:58:50.817 -0.011 -0.005 0.106 5964 2017-10-26T01:58:50.817 0.001 -0.000 0.028 5976 2017-10-28T09:23:50.817 -0.001 -0.001 -0.024 5981 2017-10-29T05:28:50.817 0.000 -0.000 0.000 5988 2017-10-30T11:13:50.817 0.000 -0.000 -0.001 5995 2017-10-31T20:13:50.817 0.000 0.000 0.002 6003 2017-11-02T05:28:50.817 -0.001 0.000 0.004 6012 2017-11-03T22:28:50.817 0.000 0.000 0.001 6022 2017-11-05T17:58:50.817 0.002 0.001 0.006 6027 2017-11-06T13:28:50.817 -0.009 0.004 0.040 6032 2017-11-07T13:38:50.817 -0.010 -0.005 -0.022 6036 2017-11-08T05:28:50.817 0.032 -0.005 -0.078 6042 2017-11-09T07:08:50.817 -0.002 0.001 0.005 6051 2017-11-10T21:38:50.817 -0.004 0.002 0.014 6058 2017-11-12T05:13:50.817 0.007 -0.002 -0.015 6066 2017-11-13T16:08:50.817 -0.002 0.000 0.005 6071 2017-11-14T12:50:13.017 -0.001 -0.000 0.001 6075 2017-11-15T06:58:50.817 -0.015 0.006 0.037 6081 2017-11-16T08:58:50.817 0.021 -0.010 -0.052 6089 2017-11-17T19:58:50.817 -0.008 0.003 0.016 6097 2017-11-19T05:50:16.017 0.002 -0.000 -0.001 6103 2017-11-20T08:35:40.017 -0.014 0.007 0.028 6109 2017-11-21T12:28:50.817 -0.048 -0.008 0.045 6122 2017-11-23T19:58:50.817 0.034 -0.013 -0.057 6130 2017-11-25T07:58:50.817 -0.020 -0.003 0.020 6141 2017-11-27T06:58:50.817 0.034 -0.011 -0.049 6148 2017-11-28T12:28:50.816 0.012 -0.005 -0.010 6157 2017-11-30T05:08:50.816 0.040 -0.005 -0.047 6166 2017-12-01T18:38:50.816 -0.018 0.004 -0.008 6177 2017-12-03T20:53:50.816 -0.045 -0.006 0.041 6187 2017-12-05T14:53:50.816 0.001 -0.001 -0.001 6194 2017-12-06T20:58:50.816 0.005 -0.002 -0.001 6204 2017-12-08T18:38:50.816 -0.043 -0.006 0.037 6213 2017-12-10T07:44:17.816 -0.020 0.007 -0.003 6225 2017-12-12T12:43:12.816 -0.037 0.018 0.025 6230 2017-12-13T10:13:50.816 0.056 -0.028 -0.022 6232 2017-12-13T18:58:50.816 -0.043 0.023 0.018 6236 2017-12-14T15:13:50.816 0.002 0.001 -0.002 6242 2017-12-15T17:38:50.816 -0.010 -0.001 0.008 6250 2017-12-17T04:51:50.816 0.011 -0.003 -0.008 6258 2017-12-18T17:28:50.816 0.022 0.002 -0.016 6263 2017-12-19T15:58:50.816 0.044 0.007 -0.031 6273 2017-12-21T12:58:50.816 0.038 0.008 -0.027 6284 2017-12-23T12:33:50.816 -0.076 0.040 0.009 6288 2017-12-24T06:33:50.816 -0.015 0.008 0.002 6300 2017-12-26T12:58:50.816 0.038 -0.013 -0.013 6309 2017-12-28T04:58:50.816 -0.018 0.009 0.002 6317 2017-12-29T16:53:50.816 -0.064 0.031 0.004 6328 2017-12-31T17:43:50.816 0.040 -0.020 0.017 End of comments.