PDS_VERSION_ID          = PDS3
RECORD_TYPE             = STREAM

OBJECT                  = TEXT
   INTERCHANGE_FORMAT   = ASCII
   PUBLICATION_DATE     = 2004-08-04
   NOTE                 = "SCL-Kernel Information"
END_OBJECT              = TEXT
                                                                     
END 


General information about SPICE SCL-kernels
===========================================

   In the SPICE system, the Spacecraft Clock (or SCL) -kernel contains
   information required to perform a mapping between Ephemeris time
   (ET) and spacecraft on-board time (SCLK).
   
   The spacecraft clock coefficient information contained in an SCLK
   file can be manipulated by a collection of subroutines to provide a
   transformation between Ephemeris and spacecraft on-board times.
   These subroutines are part of the SPICE library, the major
   component of the SPICE Toolkit. The routines needed are integrated
   into a user's application programs. Information regarding how the
   Toolkit can be obtained is located in the SOFTWARE subdirectory of
   the main directory of this dataset.
   
   Refer to the SCLK.REQ document provided with the Toolkit to get more
   information about conversion between ET and spacecraft clock times.


MER-2 SCLK files contained in this directory 
=======================================

   This volume contains the following MER-2 SCLK files (only the name
   portion of the file name is shown; the extension of all file names
   is ".tsc"):

       mer_254_sclkscet_VVVVV    MER-2 rover on-board clock correlation
                                 SPICE SCLK files generated by
                                 converting the corresponding SCLKvSCET
                                 file to SPICE SCLK format, using the
                                 MAKCLK SPICE Utility program. These
                                 files contain on-board clock
                                 correlation used during operations.
                                 For the period of surface operations
                                 this correlation is known to be in
                                 error in an absolute sense by up to 20
                                 seconds. Refer to the DATA SET catalog
                                 object for more information on this
                                 issue.

       mer2_hlst_ep55a3_vV       Special MER-2 SCLK files implementing
                                 Hybrid Local Solar Time (HLST or LSTB)
                                 time system that was used during
                                 surface operations. Refer to
                                 the DATA SET catalog object for more
                                 information about these files.

   If multiple versions of an SCLK file are provided (version is
   specified by VVVVV or vV tokens in the file name patterns above),
   always use the latest version (unless an earlier version is needed for
   some special reasons.)


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

   The most detailed description of the data in an SCLK file is
   provided in metadata included inside the description area of the
   file. This information can be viewed using any text editor program.
   

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

   Regarding MER project specific information provided in this data set
   and for general information about SPICE system:
   
      Charles H. Acton, Jr, 
      (818)-354-3869, 
      Charles.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