MAVEN Reconstructed SPK, NAV Solution, 2016-10-01 to 2017-01-01, Version 1 =========================================================================== Created by Boris Semenov, NAIF/JPL, Mon Jan 30 13:19:37 PST 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 3906 through 4383): Start of Interval (ET) End of Interval (ET) -------------------------------- -------------------------------- 2016 OCT 01 00:01:08.182 2017 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_03887-03924_rec_v1.bsp trj_orb_03924-03961_rec_v1.bsp trj_orb_03960-03997_rec_v1.bsp trj_orb_03996-04033_rec_v1.bsp trj_orb_04032-04070_rec_v1.bsp trj_orb_04069-04106_rec_v1.bsp trj_orb_04105-04142_rec_v1.bsp trj_orb_04141-04179_rec_v1.bsp trj_orb_04178-04215_rec_v1.bsp trj_orb_04214-04251_rec_v1.bsp trj_orb_04235-04288_rec_v1.bsp trj_orb_04287-04324_rec_v1.bsp trj_orb_04323-04361_rec_v1.bsp trj_orb_04360-04378_rec_v1.bsp trj_orb_04377-04427_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_161001_170101_v1.bsp, km: # #ORBNUM BOUNDARY TIME (UTC) DOWNTRK INPLANE NORMAL #------- ----------------------- ------- ------- ------- 3911 2016-10-02T06:05:57.817 -0.000 0.000 0.003 3916 2016-10-03T03:13:51.817 -0.008 0.004 0.016 3924 2016-10-04T16:23:51.817 0.019 -0.009 -0.037 3927 2016-10-05T08:58:51.817 0.005 0.002 -0.002 3932 2016-10-06T07:58:51.817 0.012 0.006 -0.009 3941 2016-10-07T23:58:51.817 -0.048 0.010 0.083 3947 2016-10-09T04:58:51.817 -0.045 -0.016 0.056 3952 2016-10-10T03:58:51.817 -0.012 -0.004 0.016 3960 2016-10-11T15:28:51.817 -0.095 0.038 0.144 3962 2016-10-12T01:43:51.817 -0.025 -0.001 0.035 3968 2016-10-13T03:58:51.817 0.074 -0.039 -0.080 3970 2016-10-13T14:58:51.817 -0.073 -0.011 0.095 3978 2016-10-15T01:58:51.817 -0.009 0.005 0.004 3983 2016-10-16T01:48:51.817 -0.001 0.000 0.001 3988 2016-10-17T01:43:51.817 0.098 -0.012 -0.120 3996 2016-10-18T14:43:51.817 -0.073 0.010 0.084 4004 2016-10-20T05:07:51.817 0.072 0.034 -0.069 4013 2016-10-21T22:23:51.817 -0.023 -0.008 0.024 4020 2016-10-23T05:58:51.817 -0.014 0.001 0.014 4026 2016-10-24T08:08:51.817 -0.007 0.004 0.000 4032 2016-10-25T14:21:58.817 -0.012 -0.004 0.011 4040 2016-10-27T01:32:17.817 0.010 -0.005 -0.006 4050 2016-10-28T23:58:51.817 -0.003 0.001 0.002 4056 2016-10-30T04:58:51.817 -0.024 -0.004 0.019 4061 2016-10-31T02:58:51.817 0.045 -0.017 -0.023 4069 2016-11-01T15:58:51.817 0.036 -0.013 -0.016 4077 2016-11-03T05:28:51.817 -0.038 0.006 0.021 4086 2016-11-04T23:58:51.817 0.011 0.003 -0.007 4092 2016-11-06T01:43:51.817 -0.005 0.003 -0.001 4097 2016-11-07T01:43:51.817 0.040 -0.011 -0.013 4100 2016-11-07T15:28:51.817 -0.022 0.007 0.006 4105 2016-11-08T14:33:51.817 -0.077 0.027 0.015 4112 2016-11-09T21:43:51.817 -0.008 0.003 -0.005 4117 2016-11-10T21:43:51.817 0.126 -0.059 0.007 4122 2016-11-11T21:58:51.817 -0.045 -0.001 0.016 4128 2016-11-13T02:28:51.817 -0.030 -0.012 0.016 4134 2016-11-14T06:18:51.817 0.032 0.013 -0.018 4141 2016-11-15T14:58:51.817 -0.009 -0.004 0.006 4148 2016-11-16T20:58:51.817 -0.046 0.022 -0.016 4153 2016-11-17T21:03:51.817 0.084 -0.010 -0.006 4157 2016-11-18T15:03:51.817 -0.045 0.015 -0.007 4160 2016-11-19T04:53:51.817 0.013 -0.004 0.002 4165 2016-11-20T02:53:51.817 0.010 -0.005 0.007 4169 2016-11-20T21:23:51.817 0.018 -0.008 0.013 4178 2016-11-22T17:28:51.817 0.034 0.010 -0.007 4183 2016-11-23T16:58:51.817 -0.036 -0.016 0.013 4188 2016-11-24T14:58:51.817 0.046 -0.002 0.006 4195 2016-11-26T00:23:51.817 0.035 0.015 -0.010 4202 2016-11-27T06:58:51.817 -0.004 0.002 -0.002 4205 2016-11-27T20:58:51.816 -0.015 0.005 -0.007 4209 2016-11-28T15:28:51.816 0.028 -0.009 0.014 4214 2016-11-29T15:08:51.816 0.044 -0.002 0.014 4221 2016-11-30T21:43:51.816 0.018 -0.008 0.013 4224 2016-12-01T13:33:51.816 -0.068 -0.005 -0.020 4231 2016-12-02T21:28:51.816 -0.046 0.005 -0.023 4235 2016-12-03T16:58:51.816 -0.115 -0.043 -0.008 4242 2016-12-04T22:33:51.816 0.006 -0.002 0.004 4250 2016-12-06T13:08:51.816 0.075 -0.008 0.048 4258 2016-12-08T01:48:51.816 0.040 -0.009 0.033 4268 2016-12-09T23:58:51.816 -0.013 0.003 -0.012 4274 2016-12-11T03:28:51.816 0.012 -0.003 0.012 4283 2016-12-12T20:58:51.816 -0.064 0.016 -0.068 4287 2016-12-13T14:28:51.816 0.003 -0.002 0.004 4292 2016-12-14T14:58:51.816 -0.033 0.000 -0.032 4297 2016-12-15T14:58:51.816 0.021 0.009 0.011 4306 2016-12-17T06:58:51.816 -0.056 0.014 -0.073 4311 2016-12-18T06:58:51.816 0.031 0.006 0.031 4318 2016-12-19T15:28:51.816 -0.014 -0.005 -0.014 4323 2016-12-20T13:08:51.816 -0.010 0.003 -0.015 4329 2016-12-21T15:43:51.816 -0.004 0.002 -0.004 4332 2016-12-22T05:33:51.816 0.011 -0.006 0.011 4340 2016-12-23T20:43:51.816 0.047 0.016 0.061 4344 2016-12-24T12:58:51.816 -0.038 0.020 -0.056 4349 2016-12-25T13:58:51.816 0.062 0.016 0.097 4354 2016-12-26T12:28:51.816 -0.036 -0.001 -0.066 4360 2016-12-27T13:48:51.816 -0.019 0.002 0.030 4369 2016-12-29T07:45:51.816 0.025 -0.013 0.032 4377 2016-12-30T21:28:51.816 0.017 -0.006 0.044 End of comments.