KPL/SCLK MSL SCLK File Implementing LMST at MVS1P100710 Landing Site =========================================================================== This file is a SPICE spacecraft clock (SCLK) kernel implementing Local Mean Solar Time (LMST). This file contains information required to convert between Ephemeris Time (ET) and LMST at the MSL landing site MVS1P100710 (Mawrth Vallis Site 1 Primary) for the landing date/time 2010-07-10T09:46:05 using SPICE SCLK time conversion routines/tools. Version -------------------------------------------------------- 1.0.0 -- January 07, 2008 -- BVS/NAIF Initial Release. References -------------------------------------------------------- 1. SCLK Required Reading Document Implementation Details -------------------------------------------------------- LMST for MSL at the landing site MVS1P100710 and landing date/time 2010-07-10T09:46:05 can be represented by a simple linear function. The starting point for this function is the ET corresponding to the midnight LMST of the SOL 0 -- 2010-07-09T17:41:06.481 UTC (or 331969331.666 ET seconds past J2000). This function "runs" 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 Martian day that appears in the COEFFICIENTS keyword below. The ID for this clock is chosen to be 76900 to indicate that this is NOT an actual SCLK for the MSL on-board clock but a special SCLK file that enables LMST-ET time conversions using the APIs of the 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 -------------------------------------------------------- In order to use the SPICELIB SCLK family routines to convert MSL LMST at the landing site MVS1P100710 to ET and vice versa, this file must be loaded into the user's program by a call to the FURNSH routine CALL FURNSH( 'this_file_name' ) furnsh_c ( "this_file_name" ); Once loaded, the routines SCE2S/sce2s_c.f can be used to convert an ET time to an LMST string in the format DDD:HR:MN:SC: CALL SCE2S( -76900, ET, LMST ) sce2s_c ( -76900, 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( -76900, LMST, ET ) scs2e_c ( -76900, lmst, &et ); 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 = ( @2008-01-07-10:27:06 ) SCLK_DATA_TYPE_76900 = ( 1 ) SCLK01_TIME_SYSTEM_76900 = ( 1 ) SCLK01_N_FIELDS_76900 = ( 4 ) SCLK01_MODULI_76900 = ( 24855 24 60 60 ) SCLK01_OFFSETS_76900 = ( 0 0 0 0 ) SCLK01_OUTPUT_DELIM_76900 = ( 2 ) SCLK_PARTITION_START_76900 = ( 0.0000000000000E+00 ) SCLK_PARTITION_END_76900 = ( 1.0995116277750E+12 ) SCLK01_COEFFICIENTS_76900 = ( 0.0000000000000E+00 331969331.666 88775.24400000 ) \begintext