
General information about SPICE PC-kernels
==========================================

   In the SPICE system, the PCK kernel provides orientation and
   ellipsoidal shape information pertaining to extended solar system
   bodies such as the Sun, the planets, the natural satellites of the
   planets, comets, and asteroids. The most recent generic PC kernel
   file based on the latest published IAU report can always be obtained
   from NAIF/JPL.

   The purpose of the PCK kernels and associated software is to provide
   SPICE users with a convenient mechanism for supplying planetary
   physical constants to application programs. SPICE PCK routines are
   able to read files conforming to the PCK format and return to a
   calling application program both the data contained in such files
   and a small number of commonly used numeric quantities derived from
   the kernel data. For information on the SPICE Toolkit and/or how to
   obtain it, please consult SPICE_INST.CAT and SOFT.CAT.

   Refer to the PCK.REQ document provided with the Toolkit to get more
   information on how to access PC-kernel data.


ROSETTA PCK Files
=================

   This file describes the contents of the DATA/PCK directory of the
   ROSETTA SPICE data set.

   PCK files in this directory are either binary or text files. The
   generic text PCK files are created manually with information from
   IAU Reports. Binary files are created using an automated process run
   by NAIF from the information contained in JPL's EOP files based on
   the IERS Earth rotation data.

   All binary PCK files (*.BPC) contained in this directory are
   little-endian (LTL-IEEE) binary files.

   All text PCK files (*.TPC) contained in this directory are UNIX text
   files with lines terminated by <LF> only.


Current PC-Kernels Contained in this Data Set
=============================================

   The following PCK-kernels are provided in this data set:

   Rosetta Mission Target Text PCKs:

      ROS_CG_RAD_V10.TPC             Contains the "Cheops reference
                                     frame" radii values for 67P/C-G.
                                     This file should be loaded when
                                     using DSKs in order to make use of
                                     all DSK API capabilities.

      ROS_CG_ROT_1408_1409_V10.TPC   Contains the "Cheops reference
                                     frame" rotation constants for
                                     67P/C-G for August-September 2014.
                                     This PCK is included only for the
                                     record because its data is
                                     applicable only to the 2014-08-01
                                     to 2014-09-30 range and must not
                                     be used for any other times.
                                     67P/C-G CKs providing orientation
                                     of the 67P/C-G_CK frame must be
                                     used instead of this PCK to get
                                     orientation of the comet.

      ROS_CGS_RSOC_V01.TPC           Contains the preliminary
                                     size/shape and orientation
                                     constants for 67P/C-G. This file
                                     is obsolete and must not be used.

      ROS_LUTETIA_RSOC_V01.TPC
      ROS_LUTETIA_RSOC_V03.TPC       Contain the size/shape and
                                     orientation constants for asteroid
                                     21 Lutetia, the RSOC solution. The
                                     file with the latest version
                                     supersedes all previous versions.
                                     The latest PCK in this set is the
                                     preferred kernel for processing
                                     the Lutetia flyby data.


      ROS_LUTETIA_LC1_V02.TPC
      ROS_LUTETIA_LC2_V02.TPC        Contain the size/shape and
                                     orientation constants for asteroid
                                     21 Lutetia, based on light curve
                                     pole solutions. The file with the
                                     latest version supersedes all
                                     previous versions.


      ROS_LUTETIA_R1_V02.TPC
      ROS_LUTETIA_R2_V02.TPC         Contain the size/shape and
                                     orientation constants for asteroid
                                     21 Lutetia, based on radar pole
                                     solutions. The file with the
                                     latest version supersedes all
                                     previous versions.


      ROS_STEINS_V03.TPC
      ROS_STEINS_V04.TPC
      ROS_STEINS_V05.TPC             Contain the size/shape and
                                     orientation constants for asteroid
                                     2867 Steins. The file with the
                                     latest version supersedes all
                                     previous versions.


   Generic Text PCKs:

      PCK00010.TPC                   Contains the size/shape and
                                     orientation constants for planets,
                                     satellites, Sun and some asteroids
                                     from the IAU 2009 report.

      PCK00008.TPC                   Contains the size/shape and
                                     orientation constants for planets,
                                     satellites, Sun and some asteroids
                                     from the IAU 2000 report. This PCK
                                     is superseded by PCK00010.TPC.

      DE403_MASSES.TPC               Contains the masses for the sun,
                                     planets, satellites and planetary
                                     barycenters. These masses are
                                     given as ratios of Solar GM to
                                     barycenter GM.


   High-precision Earth Orientation Binary PCKs:

      EARTH_000101_070916_070625.BPC
      EARTH_000101_100428_100204.BPC
      EARTH_000101_110111_101020.BPC
      EARTH_000101_120117_111026.BPC
      EARTH_000101_160131_151109.BPC
      EARTH_000101_170227_161206.BPC  Contain the orientation of the
                                      Earth as a function of time for
                                      the interval given by the first
                                      and the third dates in the file
                                      name. Starting from the second
                                      date in the name 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.


Kernel File Details
===================

   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.

   The most detailed description of the data in a binary PCK file is
   provided in metadata included inside the comment area of the file.
   This information can be viewed using utility programs 'commnt' and
   'spacit' included in the SPICE 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), Matlab (Mice), and Java
   (JNISpice) and the user can choose any one that suits him/her.

   The SPICE routine FURNSH can be used to load a kernel file into a
   SPICE-based application to make kernel data usable with SPICE
   APIs.

   In the case when two or more binary PCK files contain data
   overlapping in time for a given object 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).

