MAVEN Reconstructed SPK, NAV Solution, 2017-04-01 to 2017-07-01, Version 1 =========================================================================== Created by Boris Semenov, NAIF/JPL, Tue Aug 15 07:28:36 PDT 2017 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 4855 through 5334): Start of Interval (ET) End of Interval (ET) -------------------------------- -------------------------------- 2017 APR 01 00:01:09.185 2017 JUL 01 01:01:09.184 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_04832-04874_rec_v1.bsp trj_orb_04873-04911_rec_v1.bsp trj_orb_04910-04948_rec_v1.bsp trj_orb_04947-04985_rec_v1.bsp trj_orb_04984-05022_rec_v1.bsp trj_orb_05021-05059_rec_v1.bsp trj_orb_05058-05096_rec_v1.bsp trj_orb_05095-05124_rec_v1.bsp trj_orb_05124-05159_rec_v1.bsp trj_orb_05158-05207_rec_v1.bsp trj_orb_05206-05244_rec_v1.bsp trj_orb_05243-05281_rec_v1.bsp trj_orb_05280-05318_rec_v1.bsp trj_orb_05317-05355_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_170401_170701_v1.bsp, km: # #ORBNUM BOUNDARY TIME (UTC) DOWNTRK INPLANE NORMAL #------- ----------------------- ------- ------- ------- 4858 2017-04-01T15:58:50.814 0.180 -0.067 -0.012 4865 2017-04-03T00:48:50.814 -0.111 0.000 0.001 4873 2017-04-04T13:28:50.814 0.003 -0.000 0.000 4881 2017-04-06T02:13:50.814 -0.007 -0.002 -0.000 4891 2017-04-07T23:58:50.814 -0.013 -0.001 -0.001 4894 2017-04-08T12:56:33.814 -0.060 0.010 0.005 4899 2017-04-09T11:28:50.814 0.087 -0.026 -0.012 4902 2017-04-10T00:58:50.814 0.002 -0.001 -0.000 4910 2017-04-11T13:43:50.814 -0.009 0.003 0.001 4918 2017-04-13T01:58:50.814 0.006 -0.002 -0.001 4921 2017-04-13T15:48:50.814 0.019 -0.007 -0.004 4927 2017-04-14T19:28:50.814 -0.020 0.004 0.003 4936 2017-04-16T12:58:50.814 -0.031 -0.000 0.002 4942 2017-04-17T14:58:50.814 0.024 -0.012 -0.012 4947 2017-04-18T16:13:50.814 -0.008 -0.003 -0.002 4955 2017-04-20T03:58:50.814 0.009 0.001 -0.000 4964 2017-04-21T20:58:50.814 0.008 0.001 -0.000 4968 2017-04-22T15:13:50.814 -0.043 -0.006 0.002 4974 2017-04-23T17:28:50.814 0.024 -0.008 -0.012 4978 2017-04-24T13:33:50.814 0.004 0.002 0.001 4984 2017-04-25T16:05:50.814 -0.044 -0.005 0.005 4991 2017-04-26T23:03:50.814 0.025 -0.008 -0.014 5001 2017-04-28T20:28:50.814 -0.021 0.008 0.014 5010 2017-04-30T12:43:50.814 0.006 -0.003 -0.006 5016 2017-05-01T15:58:50.814 -0.004 0.002 0.004 5021 2017-05-02T15:48:50.814 -0.004 0.001 0.003 5028 2017-05-04T00:53:50.814 -0.005 -0.002 0.000 5032 2017-05-04T17:53:50.814 0.041 -0.012 -0.034 5038 2017-05-05T20:28:50.814 -0.007 0.003 0.008 5042 2017-05-06T15:58:50.814 -0.019 0.001 0.011 5047 2017-05-07T15:37:07.814 0.017 0.006 0.000 5052 2017-05-08T12:58:50.814 -0.013 0.004 0.014 5058 2017-05-09T15:58:50.814 0.010 -0.004 -0.014 5062 2017-05-10T11:58:50.814 0.013 0.005 0.000 5072 2017-05-12T07:58:50.814 0.005 -0.002 -0.006 5079 2017-05-13T16:58:50.814 -0.003 -0.000 0.002 5086 2017-05-15T00:58:50.814 0.011 0.003 -0.005 5095 2017-05-16T18:33:50.814 0.000 0.000 -0.000 5100 2017-05-17T13:58:50.814 0.000 -0.000 0.000 5106 2017-05-18T18:38:50.814 0.021 -0.007 -0.044 5112 2017-05-19T21:48:50.814 0.005 -0.002 -0.012 5116 2017-05-20T14:58:50.814 -0.010 0.004 0.019 5124 2017-05-22T03:23:50.814 0.014 -0.007 -0.033 5134 2017-05-24T01:58:50.814 -0.031 0.010 0.097 5142 2017-05-25T13:58:50.814 0.025 -0.011 -0.102 5152 2017-05-27T12:30:50.814 -0.029 -0.001 0.089 5158 2017-05-28T13:58:50.815 -0.008 0.004 0.036 5163 2017-05-29T14:03:05.815 0.001 -0.000 -0.004 5168 2017-05-30T12:58:50.815 0.004 0.000 -0.026 5174 2017-05-31T14:58:50.815 0.006 -0.004 -0.054 5179 2017-06-01T13:58:50.815 0.010 -0.003 -0.086 5185 2017-06-02T16:43:50.815 -0.006 0.003 0.085 5191 2017-06-03T19:48:50.815 -0.002 0.001 0.030 5197 2017-06-04T23:58:50.815 0.006 -0.002 -0.254 5206 2017-06-06T15:43:50.815 -0.001 0.000 -0.023 5210 2017-06-07T09:28:50.815 -0.002 0.000 0.058 5216 2017-06-08T13:18:50.815 0.006 -0.003 0.100 5223 2017-06-09T21:28:50.815 0.001 -0.001 0.016 5226 2017-06-10T11:13:50.815 -0.024 0.011 -0.263 5232 2017-06-11T14:28:50.815 0.018 -0.008 0.162 5238 2017-06-12T18:28:50.815 0.009 -0.001 0.053 5243 2017-06-13T15:58:50.815 0.012 -0.006 0.070 5253 2017-06-15T13:08:50.815 -0.008 0.004 -0.031 5260 2017-06-16T20:28:50.815 0.001 -0.000 -0.001 5264 2017-06-17T14:58:50.815 0.016 -0.008 0.043 5274 2017-06-19T12:18:50.815 0.009 -0.004 0.019 5280 2017-06-20T15:28:50.815 0.013 -0.006 0.023 5285 2017-06-21T14:08:50.815 0.011 -0.006 0.018 5290 2017-06-22T12:48:50.815 -0.010 0.005 -0.015 5297 2017-06-23T20:32:15.815 0.063 -0.030 0.076 5300 2017-06-24T11:58:45.815 -0.117 -0.005 -0.241 5308 2017-06-25T23:53:52.815 -0.011 0.002 -0.024 5315 2017-06-27T07:04:05.815 0.073 -0.028 0.154 5317 2017-06-27T15:58:50.815 0.078 -0.031 0.157 5322 2017-06-28T13:58:50.815 0.006 -0.003 0.008 5328 2017-06-29T19:28:50.815 -0.008 -0.002 -0.010 End of comments.