DRAG

                                                                                
----+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8
DRAG   0         7654321 2.3                                                    
----+----0----+----0----+----0----+----0----+----0----+----0----+----0----+----0
                                                                                
                                                                                
COLUMNS FORMAT         DESCRIPTION                         DEFAULT VALUE & UNITS
                                                                                
1-6     A6        DRAG   - Modifies drag application and/or                     
                  requests estimation of drag coefficients.                     
                                                                                
8       I1        Indicates order of drag coefficients:          0              
                                                                                
                    0 - Cd                                                      
                        .                                                       
                    1 - Cd                                                      
                        ..                                                      
                    2 - Cd                                                      
                                                                                
18-24   I7        Satellite ID (required).                       0              
                                        .      ..                               
25-44   D20.8     Drag coefficient.(For Cd and Cd the            0.    none or  
                  units are per second and per second                  1/S or   
                  squared)                                             1/S**2   
                                                                                
45-59   D15.3     This field must be left blank unless           0.             
                  the time dependent drag option is wanted.                     
                  To select time dependent drag specify the                     
                  end time of the period for which this                         
                  acceleration coefficient applies in the                       
                  form YYMMDDHHMMSS.SS in this field.                           
                  See NOTE[1] for more details.                                 
                                                                                
60-72   D13.1     Standard deviation of drag coefficient.              none or  
                                                                       1/S or   
                                                                       1/S**2

AUG 1988

8805.0

ARC SET - Option Cards

DRAG (cont)

                                                                                
                                                                                
 NOTE[1]:                                                                       
        Time periods may be specified only for the highest order coefficients   
        used (i.e. if Cd and Cd dot are used, only Cd dot can have time         
        intervals).                                                             
                                                                                
        When using time periods the number of drag cards required is equal      
        to the number of time periods plus the order (order = the number        
        in column 8 +1).                                                        
                                                                                
        The first DRAG card with an end time covers the time period from epoch  
        to the specified end time. Subsequent drag cards with end times cover   
        the time interval from the preceeding end time to the current end       
        time. In this manner continuous time intervals are guaranteed from      
        epoch to the last specified end time. If orbit integration continues    
        beyond the end of the last specified drag time interval, the Cd ( or    
        Cd dot, or Cd double dot) without a time interval is used. A Cd         
        (or Cd dot or Cd double dot) without a time interval is MANDATORY when  
        using this time dependent option. See example below.                    
                                                                                
                                                                                
 EXAMPLE:  Drag cards for using time dependent drag coefficients.               
           (highest order - Cd dot;two time intervals;  4 cards required)       
                                                                                
                                                                                
----+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8
DRAG   0         7654321 2.3                                                    
DRAG   1         7654321 .00002                                                 
DRAG   1         7654321 .000021             840902000000.                      
DRAG   1         7654321 .000022             840903000000.                      
----+----0----+----0----+----0----+----0----+----0----+----0----+----0----+----0
                                                                                
                                                                                
                                                                                
WARNINGS: If duplicate time periods are specified the run will terminate        
          in IIS with a warning message.                                        
          The first time period that exceeds the end time of the run            
          (see EPOCH card) will be accepted. All other end times exceeding      
          the end time of the run will be ignored.                              
                                                                                
UNITS:  KM =Kilometers; M  =Meters    ; S  =Seconds    ; Kg =Kilograms          
        DEG=Degrees   ; RAD=Radians   ; AS =Arc seconds; MAS=Milli-arc seconds  
                                                                                
                                                                                
IF CARD OMITTED: Drag is applied with a default Cd of 2.3

DEC 1992

9212.0

ARC SET - Option Cards



Patrick Dahiroc
1998-09-10