PDS_VERSION_ID          = PDS3
RECORD_TYPE             = STREAM

OBJECT                  = TEXT
   INTERCHANGE_FORMAT   = ASCII
   PUBLICATION_DATE     = 2010-08-30
   NOTE                 = "LRO 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 APIs which are part of the SPICE Toolkit
   library. These subroutines/functions 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 data set.

   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.


LRO C-kernels Contained in This Data Set
========================================

   This directory contains the SPICE C-kernel files for the LRO
   mission. All files are in IEEE big endian binary format.

   The following CK files are provided in this directory (only the
   leading portion of the file name is shown; the extension of all CK
   file names is ``.bc''):

      lrosc_YYYYDOY_yyyydoy_vNN    merged reconstructed spacecraft
                                   orientation CK files, created by
                                   merging together ``as is'' sets of 9
                                   to 11 daily LRO definitive
                                   spacecraft CK files
                                   (moc42_???????_???????_v??.bc)
                                   produced by the LRO project during
                                   operations. YYYYDOY and yyyydoy in
                                   the file name identify the period
                                   covered by the file; NN identifies
                                   the file version.

      lrohg_YYYYDOY_yyyydoy_vNN    merged reconstructed High Gain
                                   Antenna (HGA) orientation CK files,
                                   created by merging together ``as
                                   is'' sets of 9 to 11 daily LRO
                                   definitive HGA CK files
                                   (moc43_???????_???????_v??.bc)
                                   produced by the LRO project during
                                   operations. YYYYDOY and yyyydoy in
                                   the file name identify the period
                                   covered by the file; NN identifies
                                   the file version.

      lrosa_YYYYDOY_yyyydoy_vNN    merged reconstructed Solar Array
                                   (SA) orientation CK files, created
                                   by merging together ``as is'' sets
                                   of 9 to 11 daily LRO definitive SA
                                   CK files (moc44_???????_???????_v??.bc)
                                   produced by the LRO project during
                                   operations. YYYYDOY and yyyydoy in
                                   the file name identify the period
                                   covered by the file; NN identifies
                                   the file version.

      lrodv_YYYYDOY_yyyydoy_vNN    merged reconstructed DLRE
                                   orientation CK files, created by
                                   merging together ``as is'' sets
                                   hourly reconstructed DLRE CK files
                                   (lro_div_????-??-??_??.bc) produced
                                   by the DLRE team during operations.
                                   YYYYDOY and yyyydoy in the file name
                                   identify the period covered by the
                                   file; NN identifies the file
                                   version.

   If more than one CK covering the same period of time is present in
   either CK set, the CK with the latest version supersedes all CKs
   with earlier versions.
  

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 Lunar Reconnaissance Orbiter project specific information
   provided in this data set contact:

      Rick Saylor
      (301)-614-1354
      Richard.S.Saylor@nasa.gov

   address:

      NASA Goddard Space Flight Center (GSFC)
      Mail Stop 451.0
      Building 12 Room N233
      Greenbelt MD 20771