PDS_VERSION_ID          = PDS3
RECORD_TYPE             = STREAM

OBJECT                  = TEXT
   INTERCHANGE_FORMAT   = ASCII
   PUBLICATION_DATE     = 2011-03-30
   NOTE                 = "This file describes the files in the 
                          ckiss directory of this volume."
END_OBJECT              = TEXT
END


Extra data related to Cassini C-Kernels: ISS image navigation data
==================================================================

   This directory contains data related to c-smithed or image navigated
   C-Kernel (CK) pointing information. These CK's are provided in the
   "data/ck" directory, however backup information is provided in this
   directory.

   This backup information consists of pairs of files, each pair for
   about one month's data. The first file in each pair is a text file
   containing a log of angular differences between image navigated and
   AACS reconstructed CK's, for the observation times covered in the
   image navigated CK's. Such text file was produced only for CKs prior
   to May 1, 2010. The second file in each pair is a ZIP archive of
   the graphic images that resulted from the image navigation process.
   These graphic images are in JPEG format. Additional information
   about the image navigation process can be found in the comments
   sections of the image navigated CK's.


Angular Difference Log Files
======================================================================

   Angular difference logs provided in this directory have names with
   the following form:

      [StartDate]_[EndDate]c[Version]_ISS_bc_err.txt

   where:

      [StartDate]    is the coverage start date (YYDOY) of the CK;

      [EndDate]      is the coverage stop date (YYDOY) of the CK;

      [Version]      is the version of the CK.

   For example, the file 

      99213_99243ca_ISS_bc_err.txt

   contains data associated with the image navigated file
   99213_99243ca_ISS.bc. These text files contain the angular rotation
   deltas between the reconstructed 00 C-kernel and the Autonav
   C-kernel for the observation times covered in the c-smith C-kernel
   sampled at some small time interval. The columns are:

      1.  SCET Time
      2.  Total angular rotation delta in mrads
      3.  The rotation delta about the X-Axis in mrads
      4.  The rotation delta about the Y-Axis in mrads
      5.  The rotation delta about the Z-Axis in mrads
      6.  The X-Axis S/C body rate in mrad/sec
      7.  The Y-Axis S/C body rate in mrad/sec
      8.  The Z-Axis S/C body rate in mrad/sec


Navigation Process Image Archive ZIP Files
======================================================================

   Navigation process image archive ZIP files provided in this
   directory have names with the following form:

      [StartDate]_[EndDate]c[Version]_ISS_JPGs.zip

   where:

      [StartDate]    is the coverage start date (YYDOY) of the CK;

      [EndDate]      is the coverage stop date (YYDOY) of the CK;

      [Version]      is the version of the CK.

   For example, the file 

      99213_99243ca_ISS_JPGs.zip

   contains data associated with the image navigated file
   99213_99243ca_ISS.bc.

   Each of the ZIP archives contains graphic images with the names that
   have the following form:

      [Camera][SCLKTime]_[Version]_autonav.jpg

   where:

      [Camera]      is 'N' for the NAC camera or 'W' for the WAC camera.

      [SCLKTime]    is the spacecraft clock time at image shutter close.

      [Version]     is the version of the image (beginning with '1')


Contact Information
===================

   Regarding Cassini project specific information provided in this data
   set and for general information about SPICE system, contact:

      Boris Semenov 
      (818)-354-8136 
      Boris.Semenov@jpl.nasa.gov
      
   address:
   
      Navigation and Ancillary Information Facility (NAIF)
      Jet Propulsion Laboratory
      MS 301-125L
      4800 Oak Grove Drive
      Pasadena CA 91109 USA