Hera FK files
===========================================================================

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

   It was last modified on April 26, 2024 by Alfredo Escalante, ESAC/ESA.


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

   This directory contains the SPICE Frames Definition Kernel files for the
   Hera 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
     ---------------------------  -----------------------------------------
      earthfixeditrf93.tf          Makes the ITRF93 frame coincide with
                                   the Earth fixed reference frame.

      estrack_vNN.tf               ESA Ground Stations topocentric frames.

      rssd0002.tf                  Cross-mission frames kernel that defines
                                   frames of interest not ``built'' in the
                                   SPICE toolkit.

      hera_ops_vNN.tf              Hera science operations frames.

      hera_sc_didymain_npo_vNN.tf  Mapping/overwrite of HERA_SPACECRAFT to
                                   Hera Didymain Nadir-Power-Optimized frame.

      hera_vNN.tf                  Hera spacecraft, structures,
                                   instruments and sensors frames.

      hera_juventas_vNN.tf         Juventas cubesat, structures,
                                   instruments and sensors frames.

      hera_milani_vNN.tf           Milani cubesat, structures,
                                   instruments and sensors frames.

      hera_dsk_surfaces_vNN.tf     Hera Surface definitions for
                                   Digital Shape Kernels.

   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.)


 Current FK Kernels Set
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   earthfixeditrf93.tf

      SPICE FK file that makes the ITRF93 frame coincide with the Earth
      fixed reference frame.


   estrack_vNN.tf

      SPICE FK file that provides topocentric frames for the ESA Ground
      Stations. Created by the ESA SPICE Service.


   rssd0002.tf

      SPICE FK file defining a number of cross-mission frames that could be
      used by any of the users of any of the ESA planetary missions and that
      are not ``built'' in the SPICE toolkit.


   hera_ops_vNN.tf

      SPICE FK file that provides Hera science operations frames. Created by
      the ESA SPICE Service.


   hera_sc_didymain_npo_vNN.tf

      SPICE FK file that provides Mapping/overwrite of HERA_SPACECRAFT to
      Hera Didymos Nadir-Power-Optimized frame. Created by the ESA SPICE Service.


   hera_vNN.tf

      SPICE FK file that provides Hera spacecraft, structures, instruments
      and sensors frames. Created by the ESA SPICE Service.


   hera_juventas_vNN.tf

      SPICE FK file that provides Juventas cubesat, structures, instruments
      and sensors frames. Created by the ESA SPICE Service.


   hera_milani_vNN.tf

      SPICE FK file that provides Milani cubesat, structures, instruments
      and sensors frames. Created by the ESA SPICE Service.


   hera_dsk_surfaces_vNN.tf

      SPICE FK file containing surface definitions for the Digital Shape
      Kernels of Didymos, Dimorphos, and Hera.


Other directory contents
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    aareadme.txt         This file.


Particulars
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    Important information about the Mapping/overwrite frame definition
    kernels (hera_sc_didymos_npo_vNN.tf):

       These frames have been implemented to overwrite the HERA_SPACECRAFT
       frame definition provided in the Hera Frames Definitions
       kernel (hera_vNN.tf) and map it to the HERA_DIDYMOS_NPO
       frames defined in the Hera Science Operations Frames
       Definitions kernel (hera_ops_vNN.tf).

       In order to make use of these frames' kernel, ONLY ONE of these files
       MUST BE LOADED AFTER the Hera frames definition kernel and
       the Hera Science Operations Frames Definition kernel.

       NOTE THAT BY USING ANY OF THESE KERNEL, THE HERA_SPACECRAFT FRAME
       WILL BE  MAPPED TO THE CORRESPONDING SCIENCE OPERATIONS FRAME, AND
       ANY CK PROVIDING ORIENTATION FOR THE HERA_SPACECRAFT FRAME WILL
       NOT BE USED BY THE APPLICATION SOFTWARE, EVEN IF IT IS LOADED IN
       THE KERNEL POOL.


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.


Contact Information
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     If you have any questions regarding this directory or its
     contents, please contact SPICE support at ESAC:

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

     or NAIF at JPL:

             Boris Semenov
             (818) 354-8136
             Boris.Semenov@jpl.nasa.gov


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


End of aareadme file.