PDS_VERSION_ID          = PDS3
RECORD_TYPE             = STREAM

OBJECT                  = TEXT
   INTERCHANGE_FORMAT   = ASCII
   PUBLICATION_DATE     = 2008-03-25
   NOTE                 = "This file describes the files in the 
                           extras/orbnum directory of this volume."
END_OBJECT              = TEXT

END


Orbit Number Files for the CASSINI Mission
==========================================

   This directory contains orbit number files, "cas_vNN.orb",
   generated using the NAIF's ORBNUM utility program for the archived
   spacecraft trajectory SPK files for the orbital phases of the
   CASSINI mission. These orbnum files are a plain ASCII text files
   with lines terminated with a line feed character, LF (ASCII 10).
   The latest file indicated by the version "NN" in the file name 
   supersedes all earlier files.

   These files provide the orbit numbers that follow the
   "apoapsis-to-apoapsis" orbit numbering scheme -- with the orbit
   number changing at apoapsis.
 
   The information contained in these orbit number files includes the
   orbit number ("No."), apoapsis UTC time ("Event UTC APO") and SCLK
   time ("Event SCLK APO"), periapsis UTC time ("OP-Event UTC PERI"),
   planetocentric subsolar longitude and latitude ("SolLon" and
   "SolLat") at apoapsis in the Saturn body-fixed frame based on the
   IAU 2000 Saturn rotation model, planetocentric subspacecraft
   longitude and latitude ("SC Lon" and "SC Lat") at apoapsis in the
   same frame, and spacecraft altitude above Saturn ("Alt") at
   apoapsis.


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