XMM SPK files
===========================================================================

   This ``aareadme.txt'' file describes the contents of the kernels/spk
   directory of the XMM SPICE Kernel Dataset.

   It was last modified on February 24, 2023 by Ricardo Valles, ESAC/ESA.


Brief Summary
------------------------------------------------------------------------

   This directory contains the SPICE SP-Kernel files for the XMM
   mission, including mission analysis, nominal and operational spacecraft
   trajectory SPKs, generic planetary and satellite ephemeris SPKs.


File naming conventions
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   There is no agreed naming Scheme for XMM spacecraft SPKs.


Current SPK Kernels Set
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   de432s.bsp

      SPICE SPK file containing JPL planetary ephemerides version DE432,
      created by NAIF, JPL.


   xmm_horizons_YYYYMMDD_YYYYMMDD_vNN.bsp

      SPICE SPK file containing XMM spacecraft position data from
      Horizons orbit historic (concatenation of publicly released JSpOC
      two-line elements). YYYYMMDD_YYYYMMDD indicates the coverage of the SPK
      and vNN the SPK file version.
      Created by the ESA SPICE Service.


   xmm_ssm_YYYYMMDD_YYYYMMDD_vNN.bsp

      SPICE SPK file containing XMM spacecraft position data from
      measured orbit historic. YYYYMMDD_YYYYMMDD indicates the
      coverage of the SPK and vNN the SPK file version.
      Created by the ESA SPICE Service.


Other directory contents
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   aareadme.txt         This file.


Particulars
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   Trajectory data is consistent with planetary ephemeris DE-432 and with
   the leapseconds kernel naif0010.tls


Kernel File Details
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     The most detailed description of the data in a binary SPK file is
     provided in metadata included inside the comment area of the file.
     This information can be viewed using the utility programs COMMNT and
     SPACIT included in the NAIF Toolkit.


Contact Information
------------------------------------------------------------------------

   If you have any questions regarding this file contact the
   ESA SPICE Service (ESS) at ESAC:

           Alfredo Escalante Lopez
           (+34) 91-8131-429
           spice@sciops.esa.int


References and required readings
------------------------------------------------------------------------

     1. ``SPK Required Reading'', NAIF Document


End of aareadme file.
