MEX PCK Files
  =============

  This "aareadme.txt" file describes the contents of the kernels/pck directory
  of the MEX SPICE data server. It also provides the file naming conventions
  used for the MEX PCK kernels, and it provides identification of the most
  current version of each kind of PCK file.

  PCK files in this directory are either binary or text files. Text files are 
  created manually with the information from mainly the 2000 IAU Report.
  Binary files are created from the information contained in the EOP files
  provided by IERS.

  The most detailed description of the data in a text PCK file is provided in
  metadata included inside the description area of the file. This information
  can be viewed using any text editor program.

  For a binary PCK kernel, this information can be viewed using utility
  programs COMMNT and SPACIT included into the NAIF Toolkit.

  At least a basic knowledge of the SPICE system is needed in order to use
  these kernels. The SPICE toolkit provides versions in Fortran (SPICELIB), C
  (CSPICE), IDL (icy) and Matlab (mice), and the user can choose any one that
  suits him/her.

  The SPICELIB routine FURNSH, CSPICE function furnsh_c, and icy and mice
  routine cspice_furnsh load a kernel file into the kernel pool as shown
  below.

      CALL FURNSH ( 'kernel_name' )
      furnsh_c    ( "kernel_name" );
      cspice_furnsh, 'kernel_name'
      cspice_furnsh( 'kernel_name' )

  In the case when two or more files contain data overlapping in time for a
  given object, for binary kernels, the file loaded last takes precedence.

  If two (or more) text kernels assign value(s) using the '=' operator to
  identical keywords, the data value(s) associated with the last loaded
  occurrence of the keyword are used -all earlier values have been replaced
  with the last loaded value(s).

  All binary PCK files (*.BPC) contained in this directory are unix binary
  files. These may be used as is (without format conversion) in a non-unix
  environment by using any recent version of the SPICE Toolkit (Version N0052
  or later).

  All text PCK files (*.TPC) contained in this directory are unix text files.
  These may be used in a non-compatible text environment by using the ASCII
  mode of FTP to port the files.

  Contact

      ESA SPICE Team             spice@sciops.esa.int

  , or

      Alfredo Escalante Lopez    aescalante@sciops.esa.int

  if you have any questions.


  References
  ==========

  1. PCK Reading (NAIF Document).

  2. NAIF IDs Required Reading (NAIF Document).

  All the NAIF Documents are available at the NAIF web:

      http://naif.jpl.nasa.gov


  Mars Express PCK Directory Structure
  ====================================

  aareadme.txt                    This file.

  former_versions                 Subdirectory that contains obsolete versions
                                  of the PCK files that have been updated in
                                  the Current PCK Kernel Set.

  EARTH_[sdat]_[edat]_[pdat].BPC  SPICE Kernel (PCK) that contains the
                                  orientation of the Earth as a function of
                                  time for the interval from [sdat] until
                                  [edat]. From [pdat] the information
                                  contained in the file corresponds to
                                  predicted data. The rotational effects
                                  included are precession, nutation, rotation
                                  through true siderial time, polar motion and
                                  nutation corrections.

  DE403_MASSES.TPC                SPICE Kernel (PCK) that contains the masses
                                  for the sun and planetary barycenters. These
                                  masses are given as ratios to of Solar GM to
                                  barycenter GM.

  PCK00008.TPC                    SPICE Kernel (PCK) that contains the size,
                                  shape, radii and orientation constants for
                                  planets, satellites, Sun and some asteroids.


-------------------

        This file was last modified on March 22th, 2021. (R. Valles)


End of aareadme file.