KPL/SCLK

PHX SCLK File Implementing Local Mean Solar Time (LMST) at GrnVly_LLB_102407 Landing Site
===========================================================================
 
     This file is a SPICE spacecraft clock (SCLK) kernel that
     implements Local Mean Solar Time (LMST). This file contains
     information required to convert between LMST at the PHX landing
     site GrnVly_LLB_102407 and Ephemeris Time (ET) using SPICE SCLK
     time conversion routines/tools.


Version 
--------------------------------------------------------

     1.0.0 -- December 26, 2007 -- BVS/NAIF

         Initial Release.


References
--------------------------------------------------------

         1.   SCLK Required Reading Document

         2.   Phoenix Planetary Constants and Models Document 
              (PHX-377-515)

         3.   Lynn Craig's e-mail summarizing GrnVly_LLB_102407 site
              information, December 5, 2007

 
 
Implementation Details
--------------------------------------------------------

     From LTST and LMST equations in [2], one could derive that LMST
     for PHOENIX at the landing site GrnVly_LLB_102407 and landing
     date/time of 25-May-2008 23:38:20 UTC can be presented by a simple
     linear function.

     The starting point for this function will be ET corresponding to
     the midnight LMST of the SOL 0 specified in [3] as 25-May-2008 
     06:51:18 UTC (or 264970343.185 ET seconds past J2000.)

     This function will "run" at the constant rate of 1.02749125 ET
     seconds in 1 local Martian second, which is equal the SCLK rate of
     88775.24400000 ET seconds in 1 local day appearing in the
     COEFFICIENTS keyword below.
 
     The ID for this clock is chosen to be 84900 to indicate that this
     is NOT a actual SCLK for the PHX but rather a convenient way to
     implement LMST using SCLK subsystem of SPICE.


LMST Format
--------------------------------------------------------

     The LMST string, the conversion for which is provided by this SCLK
     file, consists of four fields:

          DDD:HR:MN:SC

     where:

          DDD  -- count of LMST (SOL) days
          HR   -- count of LMST hours
          MN   -- count of LMST minutes
          SC   -- count of LMST seconds


Usage
--------------------------------------------------------
 
     This file must be loaded into the user's program by a call to the
     FURNSH subroutine
 
          CALL FURNSH( 'this_file_name' )
          furnsh_c   ( "this_file_name" );
 
     in order to use the SPICELIB SCLK family of subroutines to convert
     PHX LMST at the landing site GrnVly_LLB_102407 to ET and vice versa.
 
     Once loaded, the SCE2S/sce2s_c.f routines can be used to convert
     an ET time to an LMST string in the format DDD:HR:MN:SC:

          CALL SCE2S( -84900, ET,         LMST )
          sce2s_c   ( -84900, et, maxlen, lmst );
 
     and the routines SCS2E/scs2e_c can be used for backward conversion
     -- from LMST in DDD:HR:MN:SC format to ET:

          CALL SCS2E( -84900, LMST,  ET )
          scs2e_c   ( -84900, lmst, &et );
   

Production/History of this SCLK file
--------------------------------------------------------
 
     This file was generated manually using the PHOENIX LMST definition
     provided in [2] and the LMST0 reference point provided for the
     landing site GrnVly_LLB_102407 in [3].
 
 
Inquiries
--------------------------------------------------------
 
     If you have any questions regarding this file contact NAIF at JPL
 
           Charles H. Acton, Jr
           (818) 354-3869
           Chuck.Acton@jpl.nasa.gov
 
           Boris V. Semenov
           (818) 354-8136
           Boris.Semenov@jpl.nasa.gov
 

Kernel DATA
--------------------------------------------------------

     \begindata

         SCLK_KERNEL_ID              = ( @2007-12-26/12:00 )

         SCLK_DATA_TYPE_84900        = ( 1 )
         SCLK01_TIME_SYSTEM_84900    = ( 2 )
         SCLK01_N_FIELDS_84900       = ( 4 )
         SCLK01_MODULI_84900         = ( 24855 24 60 60 )
         SCLK01_OFFSETS_84900        = ( 0     0  0  0  )
         SCLK01_OUTPUT_DELIM_84900   = ( 2 )

         SCLK_PARTITION_START_84900  = ( 0.0000000000000E+00 )

         SCLK_PARTITION_END_84900    = ( 1.0995116277750E+12 )

         SCLK01_COEFFICIENTS_84900   = ( 
             0.0000000000000E+00     264970343.185     88775.24400000  
                                  )  

     \begintext