REFRAC

                                                                                
----+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8
REFRAC 1                                                                        
----+----0----+----0----+----0----+----0----+----0----+----0----+----0----+----0
                                                                                
                                                                                
COLUMNS FORMAT         DESCRIPTION                         DEFAULT VALUE & UNITS
                                                                                
1-6     A6     REFRAC - Specifies the tropospheric                              
               model to be used for tropospheric                                
               corrections to the observations.                                 
                                                                                
8       I1     Model selection number                             0             
                                                                                
                = 0 Hopfield Model                                              
                = 1 Marini Murray Model [NOTE 1]                                
                = 2 VLBI/GPS                                                    
                = 3 GPS Model using Neil mapping functions
                = 4 Marini Murray for laser data
                    Model 03 for nonlaser data
                                                                                
9       I1     Correction Component Applied                       0             
                                                                                
                = 0 Wet and Dry                                                 
                = 1 Wet Only                                                    
                = 2 Dry Only                                                    
                                                                                
10      I1     Scale Factor Adjustment                            0             
                                                                                
                = 0 K*(Wet + Dry)                                               
                = 1 K*Wet Only                                                  
                                                                                
11      I1     Wet Component Mapping Function (Model 2)           0             
                                                                                
                = 0 Chao                                                        
                = 1 CFA2.2                                                      
                                                                                
12      I1     Dry Component Mapping Function (Model 2)           0             
                                                                                
                = 0 Chao                                                        
                = 1 CFA2.2

APR 1997

9704.0

GLOBAL SET

REFRAC (cont)

                                                                                
NOTES:                                                                          
                                                                                
 [1]  The Marini Murray model is only available for laser range data.   If 
      the Marini Murray model is selected (column 8 =1) and data other
      than laser range is present, the Hopfield model will be used
      for all non laser range data and the Marini Murray model will be used for
      the laser range data.  
                                                                                
                                                                                
                                                                                
                                                                                
                                                                                
                                                                                
                                                                                
                                                                                
IF CARD OMITTED:  Hopfield model will be used for non laser range data.
                  Marini Murray model will be used for laser range data.
JUNE 1991

9106.0

GLOBAL SET



Patrick Dahiroc
1998-09-10