PDS_VERSION_ID               = PDS3                                           
RECORD_TYPE                  = FIXED_LENGTH                                   
RECORD_BYTES                 = 2880                                           
FILE_RECORDS                 = 181                                            
^IMAGE                       = ("JGD75B50.IMG",1)                             
INSTRUMENT_HOST_NAME         = "MARS GLOBAL SURVEYOR"                         
TARGET_NAME                  = "MARS"                                         
INSTRUMENT_NAME              = "RADIO SCIENCE SUBSYSTEM"                      
DATA_SET_ID                  = "MGS-M-RSS-5-SDP-V1.0"                         
ORIGINAL_PRODUCT_ID          = "MGS75B.GEOID"                                 
PRODUCT_ID                   = "JGD75B50.IMG"                                 
PRODUCT_RELEASE_DATE         = 1999-09-28                                     
DESCRIPTION                  = "                                              
                                                                              
 This file contains a digital map of the gravity anomaly derived from         
 the MGS75B model of the Mars gravity field.  Each point gives the Mars       
 gravity anomaly in milligals, which is the difference of the model           
 gravity on the geoid from the normal gravity on a reference ellipsoid        
 with semi-major-axis = 3397.0 km, GM = 42828.35796 km**3/s**2,               
 flattening = 5.079304192e-3, and rotation rate = 7.088218081e-5 rad/s.       
 The JGD75B50 gravity anomaly is computed from a truncated MGS75B             
 solution (from degree 2 up to degree 50).  'GD' in the file name             
 indicates it is Gravity anomaly Data, '75B' denotes the MGS75B model         
 solution used, and '50' indicates the maximum degree of the field            
 used to create the map.                                                      
                                                                              
 The map is produced by the Mars Global Surveyor Gravity Science Team         
 at JPL under the direction of William L. Sjogren.                            
                                                                              
 NB: Orbit numbers in keywords below are counted from Mars Orbit              
 Insertion in September 1997.  The MGS Project reset its orbit count          
 at the beginning of Mapping in early March 1999; the reset is not            
 included in either START_ORBIT_NUMBER or STOP_ORBIT_NUMBER."                 
                                                                              
                                                                              
START_ORBIT_NUMBER           = 202                                            
STOP_ORBIT_NUMBER            = 1930                                           
START_TIME                   = 1998-03-28T00:00:00.000                        
STOP_TIME                    = 1999-03-29T05:30:00.000                        
SOFTWARE_NAME                = "GRVMAP;V1.0"                                  
PRODUCT_CREATION_TIME        = 1999-09-28T00:00:00.000                        
PRODUCER_ID                  = "MGS GRAVSCI TEAM"                             
                                                                              
OBJECT               = IMAGE                                                  
  LINES                      = 181                                            
  LINE_SAMPLES               = 360                                            
  SAMPLE_TYPE                = "IEEE REAL"                                    
  SAMPLE_BITS                = 64                                             
  UNIT                       = "METERS"                                       
  OFFSET                     = 0.0E+00                                        
  SCALING_FACTOR             = 1.0E+00                                        
  DESCRIPTION                = "The Digital Map contains                      
values of the gravity anomaly.  The values can be obtained                    
by multiplying the sample in the map by SCALING_FACTOR                        
and then adding OFFSET."                                                      
END_OBJECT           = IMAGE                                                  
                                                                              
OBJECT               = IMAGE_MAP_PROJECTION                                   
  ^DATA_SET_MAP_PROJECTION     = "DSMAP.CAT"                                  
  COORDINATE_SYSTEM_TYPE       = "BODY-FIXED ROTATING"                        
  COORDINATE_SYSTEM_NAME       = PLANETOCENTRIC                               
  MAP_PROJECTION_TYPE          = "SIMPLE CYLINDRICAL"                         
  A_AXIS_RADIUS                = 3397.0 <KM>                                  
  B_AXIS_RADIUS                = 3397.0 <KM>                                  
  C_AXIS_RADIUS                = 3397.0 <KM>                                  
  FIRST_STANDARD_PARALLEL      = "N/A"                                        
  SECOND_STANDARD_PARALLEL     = "N/A"                                        
  POSITIVE_LONGITUDE_DIRECTION = "EAST"                                       
  CENTER_LATITUDE              = 0.0 <DEG>                                    
  CENTER_LONGITUDE             = -0.5 <DEG>                                   
  REFERENCE_LATITUDE           = 0.0 <DEG>                                    
  REFERENCE_LONGITUDE          = 0.0 <DEG>                                    
  LINE_FIRST_PIXEL             = 1                                            
  LINE_LAST_PIXEL              = 181                                          
  SAMPLE_FIRST_PIXEL           = 1                                            
  SAMPLE_LAST_PIXEL            = 360                                          
  MAP_PROJECTION_ROTATION      = 0.0 <DEG>                                    
  MAP_RESOLUTION               = 1.0E+00                                      
  MAP_SCALE                    = "N/A"                                        
  MAXIMUM_LATITUDE             = 90.0 <DEG>                                   
  MINIMUM_LATITUDE             = -90.0 <DEG>                                  
  EASTERNMOST_LONGITUDE        = 179.0 <DEG>                                  
  WESTERNMOST_LONGITUDE        = -180.0 <DEG>                                 
  LINE_PROJECTION_OFFSET       = 90.0                                         
  SAMPLE_PROJECTION_OFFSET     = 180.0                                        
END_OBJECT           = IMAGE_MAP_PROJECTION                                   
                                                                              
END