EnVision FK files
==============================================================================

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

   It was last modified on June 5, 2025 by Alfredo Escalante, ESAC/ESA.


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

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


References and required readings
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   1. ``Frames Required Reading'', NAIF Document

   2. ``Kernel Pool Required Reading'', NAIF

   3. ``C-Kernel Required Reading'', NAIF

          
Brief Summary
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   This directory contains the SPICE Frames Definition Kernel files for the
   EnVision spacecraft, its structures, and science instruments, as well as
   for the Ground Earth Stations. Moreover, it contains frame definitions for
   science operations and for data analysis and scientific investigations.


File naming conventions
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   The following table provides information on which file contains which
   frames, their file naming conventions and some particular details:
   
       File                          Contents
      ----------------------------  ------------------------------------------
       earth_topo_YYMMDD.tf          NASA DSN Ground Stations topocentric
                                     frames.

       estrack_vNN.tf                ESA Ground Stations topocentric frames

       envision_vNN.tf               EnVision spacecraft, structures,
                                     instruments and sensors frames

       envision_sc_venus_npo_vNN.tf  Frames kernel that always aligns the
                                     EnVision spacecraft reference frame
                                     with Nadir-Power-Optimized attitude.

       rssd00NN.tf                   Cross-mission frames kernel that defines
                                     frames of interest not ``built'' in the
                                     SPICE toolkit.

      where

         NN             version number -- two digits (required)

                        If multiple versions of a Frames Kernel file are
                        provided, always use the latest version (unless
                        earlier version is needed for some special reasons.)

         CREF          crema reference (required)


Other directory contents
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   aareadme.txt         This file.


Particulars
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   Nothing to report.


Kernel File Details
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   The most detailed description of the data in an FK file is provided in
   metadata included inside the descriptive text areas of the file. This
   information can be viewed using any text editor.


End of aareadme file.