KPL/SCLK

PHX SCLK File Implementing Local Mean Solar Time (LMST) at DAB1 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 DAB1 and Ephemeris Time (ET) using SPICE SCLK time conversion
     routines/tools.


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

     1.0.0 -- August 28, 2007 -- BVS/NAIF

         Initial Release.


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

         1.   SCLK Required Reading Document

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

         3.   Mark Garcia's e-mail summarizing DAB1 site information,
              August 28, 2007

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

     From LTST and LMST equations in [2], one could derive that LMST
     for PHOENIX at the landing site DAB1 and launch at the start of the
     launch window resulting in landing on May 25, 2008 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 2008-05-25 
     06:51:20 UTC (or 264970345.185 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 DAB1 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 computed for the
     landing site DAB1.
 
 
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              = ( @2007-08-28/12:00 )

	 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     264970345.185    88775.24400000  
				  )  

     \begintext