VEX LSK Files                                                               
  =============                                                               
                                                                              
  This "aareadme.txt" file describes the contents of the kernels/lsk          
  directory. It also provides the file naming conventions used for the VEX 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).                                
                                                                              
  The most detailed description of the data in an IK 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    
  this kernels. The SPICE toolkit provides versions in Fortran (SPICELIB), C  
  (CSPICE) and IDL (icy), and the user can choose any one that suits him/her. 
                                                                              
  The SPICELIB routine FURNSH, CSPICE function furnsh_c, and icy and mice     
  routine cspice_furnsh load a kernel file into the kernel pool as shown      
  below.                                                                      
                                                                              
      CALL FURNSH ( 'kernel_name' )                                           
      furnsh_c    ( "kernel_name" );                                          
      cspice_furnsh, 'kernel_name'                                            
      cspice_furnsh( 'kernel_name' )                                          
                                                                              
                                                                              
  In the case when two or more files contain data overlapping in time for a   
  given object, for binary kernels, the file loaded last takes precedence.    
                                                                              
  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).                                              
                                                                              
                                                                              
  All LSK files (*.TLS) contained in this directory are unix text files. These
  may be used in a non-compatible text environment by using the ASCII mode of 
  FTP to port the file.                                                       
                                                                              
  Contact                                                                     
                                                                              
        ESA SPICE Team       esa_spice@sciops.esa.int                                
                                                                              
  , or                                                                        
                                                                              
    Jose Luis Vazquez    jlvazquez@sciops.esa.int                             
                                                                              
  if you have any questions.                                                  
                                                                              
                                                                              
                                                                              
References                                                                    
==========                                                                    
                                                                              
   1. Time Required Reading (NAIF Document).                                  
                                                                              
   All the NAIF Documents are available at the NAIF web:                      
                                                                              
      http://naif.jpl.nasa.gov                                                
                                                                              
                                                                              
                                                                              
                                                                              
Venus Express LSK Directory Structure                                         
====================================                                          
                                                                              
 aareadme.txt        Text file describing the directory structure, the naming 
                     conventions for the LSKs, and the current version(s) of  
                     each LSK type.                                           
                                                                              
 former_versions     Subdirectory that contains obsolete versions of the      
                     LSK files that have been updated in the Current LSK      
                     Kernels Set.                                             
                                                                              
 NAIFvvvv.TLS        File storing the occurrences of leapseconds. vvvv is the 
                     version number of the file.                              
                                                                              
                                                                              
                                                                              
-------------------                                                           
                                                                              
        This file was last modified on March 17th, 2009. (J. Vazquez)