General information about SPICE LS-kernels ========================================== In the SPICE system, the Leapsecond (or LS) -kernel contains a tabulation of the leapseconds and other data required to perform a transformation between Universal Time Coordinated (UTC) and Ephemeris time (ET, also called Barycentric Dynamic Time, or TDB). Leapseconds may occur at the New Year or the end of June. The information in an LSK file can be manipulated by a collection of subroutines to provide required time system transformations. These subroutines are part of the SPICE library, the principal component of the SPICE Toolkit, and can be integrated into a user's application program. For information on the SPICE Toolkit and/or how to obtain it, please consult SPICE_INST.CAT and SOFT.CAT. Refer to the TIME.REQ document provided with the Toolkit to get more information about time conversions supported within the SPICE system. Mars Express LSK Files ======================= This file describes the contents of the DATA/LSK directory. It also provides the file naming conventions used for the Mars Express LSK kernels, and it provides identification of the most current version of LSK files. The LSK file is modified every time a new Leapsecond is announced by the International Earth Rotation Service (IERS). All LSK files (*.TLS) contained in this directory are UNIX text files with lines terminated by only. Mars Express Leap Seconds Kernels Contained in this Data Set ============================================================ The following LS-kernels are provided in this data set: NAIFvvvv.TLS SPICE Kernel (LSK) specifying the relationship between the Barycentric Dynamical Time (TDB, also called Ephemeris Time, ET) and Coordinated Universal Time (UTC) up to the last modification in the Leapseconds. Note that when several LSK kernels are provided in the data set, the most recent one supersedes all the others. Kernel File Details =================== The most detailed description of the data in a text LSK file is provided in metadata included inside the description area of the file. This information can be viewed using any text editor program. At least a basic knowledge of the SPICE system is needed in order to use these kernels. The SPICE Toolkit provides versions in Fortran (SPICELIB), C (CSPICE), IDL (Icy), Matlab (Mice), and Java (JNISpice) and the user can choose any one that suits him/her. The SPICE routine FURNSH can be used to load a kernel file into a SPICE-based application to make kernel data usable with SPICE APIs. If two (or more) text kernels assign value(s) using the '=' operator to identical keywords, the data value(s) associated with the last loaded occurrence of the keyword are used -all earlier values have been replaced with the last loaded value(s).