PDS_VERSION_ID        = PDS3                                                  
RECORD_TYPE           = STREAM                                                
OBJECT                = TEXT                                                  
  PUBLICATION_DATE      = 2000-10-12                                          
  NOTE                  = "INFO.TXT describes the DATA/ANCIL directory        
                           contents."                                         
END_OBJECT            = TEXT                                                  
END                                                                           
                                                                              
This directory contains kernel files. The files in this group all are         
ASCII text files. Copies of these files also exist in the GEOMETRY            
directory on this disk.                                                       
                                                                              
                                                                              
     MAG_ER.TI,    a SPICE MAG/ER instrument kernel containing a MAG/ER       
                   instrument mounting description. (JPL NAIF)                
                                                                              
     MO_MAGS.KER,  a magnetometer constants file used for conversion          
                   of telemetry.                                              
                                                                              
     MO_OBJ.KER,   a file that provides information about program             
                   variables used in preparation of the data.                 
                   (GSFC MAG)                                                 
                                                                              
     PCK.TPC,      a "planetary constants" (PCK) kernel file, which           
                   contains constants needed by NAIF subroutines              
                   which require body size, orientation, etc. (JPL NAIF)      
                   Any coordinate system transformation to body fixed         
                   or quasi body fixed coordinates consults this file.        
                   It will be altered from time to time as deemed             
                   necessary by NAIF.                                         
     SCLK.KER,     a spacecraft clock kernel file for the time                
                   period spanned by the data.                (JPL NAIF)      
                   This is one of two files needed to convert spacecraft      
                   tics - the long binary word in the header, roughly         
                   equal to seconds past a specific date - to Universal Time. 
                   This file will change from time to time.                   
     LEAP.KER,     a "leapseconds" file, contains time conversion             
                   data needed by NAIF subroutines.           (JPL NAIF)      
                   This is a short file that contains a list of leapseconds,  
                   also needed to convert spacecraft tics to UTC.             
     HGA.TF,       a Frames Kernel file (FK),                                 
                   contains set of frame definitions for the Mars Global      
                   Surveyor High and Low gain antennas.       (JPL NAIF)      
     SC_MOD.KER,   Spacecraft Magnetic Field Model File for Mars Global       
                   Surveyor                                   (GSFC MAG)      
                                                                              
This directory also contains a detached PDS label for each of these           
files. The label describing a given file has the same filename as the         
file, but with the extension changed to LBL (for example, MAG_ER.LBL).        
                                                                              
Copies of the kernel files from this directory, and of their labels,          
also exist in the GEOMETRY directory. Users with Web browsers may access      
these copies of the kernels either directly or via links in the HTML          
file GEOMETRY.HTM in the EXTRAS directory. Such users also can navigate       
the entire disk using the file AAREADME.HTM in the disk root directory.