EARTH

                                                                                
----+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8
EARTH 0        20 20         3.986004359D+14 6378144.11    298.255              
----+----0----+----0----+----0----+----0----+----0----+----0----+----0----+----0
                                                                                
                                                                                
COLUMNS FORMAT         DESCRIPTION                         DEFAULT VALUE & UNITS
                                                                                
1-5     A5     EARTH - Modifies the earth's                                     
               gravitational potential and/or                                   
               introduces new earth constants.                                  
                                                                                
7       I1     Gravity model initalization indicator.             0             
                                                                                
               = 0 Gravitational coefficients are                               
                   initialized from gravity model file.                         
                   They may be changed by GCOEF, GCOEFC                         
                   or GCOEFS cards.                                             
                                                                                
               > 0 Gravitational coefficients are set                           
                   to zero except those which appear on                         
                   GCOEF, GCOEFC, or GCOEFS cards which                         
                   follow this card.                                            
                                                                                
8       I1     Gravity model print control switch.                0             
                                                                                
               = 0  Print two portions of model:                                
                    1. lowest degree & order; and                               
                    2. highest degree & order.                                  
                                                                                
               = 1  Print entire gravity model.    :                            
                                                   : N/A                        
               = 2  Print only model checksum.     :                            
                                                                                
9       I1     Indicator of the contents of the                   0             
               remainder of this card:                                          
                                                                                
               = 0  Columns 25-72 contain the                                   
                    values for GM, ae,1/fe.                                     
                                                                                
               = 1  Columns 25-72 contain the                                   
                    sigmas for GM, ae, 1/fe.
JULY 1987

8704.0

GLOBAL SET

EARTH (cont)

                                                                                
COLUMNS FORMAT         DESCRIPTION                         DEFAULT VALUE & UNITS
                                                                                
15-17   I3     Maximum degree of coefficient to be                3             
               used in the gravitational model.                                 
               Minimum =3.  Default depends on gravity                          
               model file on unit 12.(See NOTES)                                
                                                                                
18-20   I3     Maximum order of coefficient to be                 2             
               used in the gravitational model.                                 
               minimum =2.  Default depends on                                  
               gravity model file on unit 12.                                   
                                                                                
25-44   D20.8  Universal gravitational constant           3.9860064D14 M**3/S**2
               times the mass of the Earth (GMe)                                
               or sigma value if column 9 =1                                    
                                                                                
45-59   D15.3  Semi-major axis of the Earth (Ae) or        6378138.0        M   
               sigma value if column 9 =1                                       
                                                                                
60-72   D13.1  Inverse of the Earth's flattening             298.255            
               (1/fe) or sigma value if column 9 =1                             
                                                                                
                                                                                
                                                                                
                                                                                
                                                                                
NOTES:                                                                          
   [1]  The default values for degree and order of the gravity field and        
        the Earth constants are overridden by the values from the gravity       
        model file on unit 12.                                                  
                                                                                
   [2]  EARTH and PLANET are actually the same keyword card except that         
        EARTH automatically supplies the planet number (0300) and does not      
        have planetary position adjustment capability.                          
                                                                                
                                                                                
UNITS:  KM =Kilometers; M  =Meters    ; S  =Seconds    ; M/S=Meters per second  
                                                                                
                                                                                
                                                                                
IF CARD OMITTED:  The complete geopotential field contained in                  
                  the default gravity model file on UNIT 12 will be used.
AUG 1985

8507.0

GLOBAL SET



Patrick Dahiroc
1998-09-10