PDS_VERSION_ID          = PDS3
RECORD_TYPE             = STREAM

OBJECT                  = TEXT
   INTERCHANGE_FORMAT   = ASCII
   PUBLICATION_DATE     = 2006-03-08 
   NOTE                 = "C-Kernel Information"
END_OBJECT              = TEXT
                                                                     
END 


General information about SPICE C-kernels
=========================================

   In the SPICE system, pointing data for an instrument platform, or
   for a specific instrument, are stored C-kernels.  The pointing of
   a platform or an instrument is often expressed in terms of a
   transformation matrix from some standard inertial reference frame
   to a instrument-fixed frame. In the past, the instrument was often
   a camera, and the transformation was thus dubbed the ``C-matrix'';
   hence the choice of C as the name for the pointing kernel.
   
   The data contained in C-kernel files can be accessed and manipulated
   by a collection of FORTRAN 77 subroutines which are part of the
   SPICELIB library. These subroutines can be integrated into user
   application programs. The SPICE system toolkit for a number of
   computer platforms or information regarding how it can be obtained
   is located in the SOFTWARE subdirectory of the main directory of
   this dataset.
   
   To use C-kernels, a Spacecraft Clock Kernel (SCLK) is required.
   Also, for C-Kernels containing orientation of a project-defined
   frames, a Frame Definitions File is required.
   
   Refer to the CK.REQ document provided with the toolkit or available
   from the NAIF Node of PDS if SPICE toolkit is not included with
   this data set to get more information on how to access C-kernel
   data.


Stardust C-kernels contained in this volume
===========================================

   This volume contains the SPICE C-Kernel files for the Stardust
   spacecraft and NAVCAM instrument. The following binary CK files are
   present in this volume (only file names are shown; the file name
   extensions of the binary CK files are always ".bc"):

      sdu_sc_rec_YYYY[_vX]   Stardust spacecraft orientation CK files.
                             Each of these files covers the year
                             specified by the YYYY token of the name.
                             The file for the year 2003 also covers the
                             first half of January 2004, during which
                             the Wild 2 encounter and post encounter
                             observations have occurred. This longer
                             coverage is indicated by the YYYY token
                             set to 2003_w2. The file for 2005 also 
                             covers the beginning of 2006, through
                             the end of the Earth return phase.

                             These CKs contain s/c orientation that was
                             extracted from the channelized telemetry,
                             small forces packets, and NAVCAM image
                             headers. If more than one file is present
                             for any of the years, the file with latest
                             version (_vX) supersedes all other files
                             for that year.

      sdu_sc_rec_w2_opnav    Stardust spacecraft orientation CK file,
                             containing s/c attitude for the Wild 2
                             encounter, determined as part of the
                             Optical Navigation (OPNAV) team geometry
                             solution for the encounter.

      sdu_nc_rec[_vX]        NAVCAM orientation CK files. These files
                             contains data required to compute NAVCAM
                             pointing w.r.t the spacecraft. 

                             These CKs contain contain discrete data
                             points computed from the mirror angle
                             values included in the image headers and
                             corresponding to the exact times when the
                             images were taken. Therefore, they cannot
                             be used to compute the camera view
                             direction for any other times. To get
                             these exact times users interested in
                             computing NAVCAM orientation using these
                             CKs must start with SCLK values provided
                             in the SPACECRAFT_CLOCK_START_COUNT
                             keywords in the NAVCAM image labels and
                             convert these SCLKs to other time
                             system(s) to access SPICE data. Starting
                             with UTC times from the NAVCAM labels will
                             result in a small round off and the
                             pointing will not be found.

                             If more than one NAVCAM CK file is
                             present, the file with latest version
                             (_vX) supersedes all other files.

      sdu_coll_nom[_vX]      Dust collector orientation CK files. These
                             files contain commanded orientation of the
                             dust collector grid with respect to the
                             spacecraft.

                             If more than one collector CK file is
                             present, the file with latest version
                             (_vX) supersedes all other files.
  
Kernel file details
===================

   The most detailed description of the data in a binary CK 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 into the NAIF Toolkit.

  
Contact information
===================

   Regarding Stardust project specific information provided in this
   data set and for general information about SPICE system:
   
      Charles H. Acton, Jr, 
      (818)-354-3869, 
      Chuck.Acton@jpl.nasa.gov, 
      
   or 
   
      Boris Semenov 
      (818)-354-8136 
      Boris.Semenov@jpl.nasa.gov
      
   or 
   
      Lee Elson
      (818)-354-4223 
      Lee.Elson@jpl.nasa.gov

   address:
   
      Navigation and Ancillary Information Facility (NAIF)
      Jet Propulsion Laboratory
      MS 301-125L
      4800 Oak Grove Drive
      Pasadena CA 91109 USA 

