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

  Last Update: 12 MAY 2006

  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

  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). [Ref 2a]

  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. [Ref 2a]

  Contact Jose Luis Vazquez (jlvazquez@sciops.esa.int) or Joe Zender 
  (Joe.Zender@esa.int) if you have any questions.

=============================================================================
References
=============================================================================

  1. PCK Reading. NAIF Document No. 254.05  17 Jan 2002 

  2. Selected SPICE Tutorials from the NAIF server:
ftp://naif.jpl.nasa.gov/pub/naif/toolkit_docs/Tutorials/office/individual_docs/
       
       a) Porting Kernels Tutorial     09_porting_kernels.ppt
       b) PCK Tutorial                 16_pck.ppt

  3. NAIF IDs Required Reading. NAIF Document No. 219.12  30 Jul 2003

=============================================================================
Mars Express PCK Directory Structure
=============================================================================
  aareadme.txt        Text file describing the directory structure, the naming
                      conventions for the PCK, and the current version(s) of
                      each PCK type.

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

=============================================================================
MEX Binary PCK Naming Convention              EARTH_[sdat]_[edat]_[pdat].BPC
=============================================================================

      token           description
      ---------       -------------------------------------------------------
       [sdat]         Coverage start time of the file in YYMMDD format.

       [edat]         Coverage end time of the file in YYMMDD format.

       [pdat]         Start time for the predicted data in the file in YYMMDD
                      format.

=============================================================================
Current PCK Kernels Set
=============================================================================

 Name                            Comments
 ------------------------------  --------------------------------------------
 EARTH_[sdat]_[edat]_[pdat].BPC  PCK file containing the orientation of the
                                 Earth as a function of time for the interval
                                 [sdat] to [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.

 MARS_IAU2000_Vx.TCP             PCK file containing the radii and orientation 
                                 constants for Mars and its natural satellites

 DE403-MASSES.TPC                PCK file containing the masses for the sun and
                                 planetary barycenters. These masses are given
                                 as ratios to of Solar GM to barycenter GM.

 PCK00008.TPC                    PCK file containing the size, shape, radii
                                 and orientation constants for planets,
                                 satellites, Sun and some asteroids.