PDS_VERSION_ID = PDS3 RECORD_TYPE = STREAM OBJECT = TEXT INTERCHANGE_FORMAT = ASCII PUBLICATION_DATE = 2012-10-30 NOTE = "GRAIL SCL-Kernel Information" END_OBJECT = TEXT END General information about SPICE SCL-kernels =========================================== In the SPICE system, Spacecraft Clock (or SCL) -kernel contains a set of information required to perform a mapping between Ephemeris time (ET) and spacecraft on-board time (SCLK). The spacecraft clock coefficient information contained in the SCLK files can be manipulated using the SPICE Toolkit APIs, calls to which can be integrated into user application programs. The information regarding how to obtain the SPICE system toolkit for a number of languages and computer platforms is located in the ``/software'' subdirectory of the main directory of this data set. Refer to the ``sclk.req'' document provided with the toolkit to get more information about conversion between ET and spacecraft clock times. GRAIL SCL-kernels contained in this directory ============================================= This volume contains the following GRAIL SCLK files (only the leading portion of the file name is shown; the extension of all file names is ``.tsc''): SC_sclkscet_VVVVV GRAIL Spacecraft clock coefficients kernel (SCLK) files providing correlation data for the primary GRAIL-A (SC=gra) or GRAIL-B (SC=grb) on-board clock tags where VVVVV is the file version (example: ``00005'' for Version 5). These SCLK files contain actual GRAIL on-board clock to ET mapping coefficients computed using time calibration packets from the spacecraft engineering telemetry. If multiple versions of an SCLK file are provided, always use the latest version unless an earlier version is needed for consistency purposes. Kernel File Details =================== The most detailed description of the data in an SCLK file is provided in metadata included inside the descriptive text areas within the file. This information can be viewed using any text editor. Contact Information =================== Regarding GRAIL project specific information provided in this data set and for general information about SPICE system: 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