PDS_VERSION_ID        = PDS3                                                  
RECORD_TYPE           = STREAM                                                
OBJECT                = TEXT                                                  
  PUBLICATION_DATE      = 2000-03-17                                          
  NOTE                  = "Text describes the magnetometer calibration."      
END_OBJECT            = TEXT                                                  
END                                                                           
                                                                              
MAG Calibration Parameters for the J0/Io Flyby:                               
                                                                              
onboard calibration (12/7/95):                                                
  gains (eng. units):       G1 =  16244                                       
                            G2 =  16670                                       
                            G3 =  16475                                       
                                                                              
  offsets (eng. units):     O1 =     75                                       
                            O2 =      3                                       
                            O3 =     75                                       
                                                                              
  matrix (eng. units):    170     -32766      -1817                           
                        32765        154       -155                           
                           56      -1777      32765                           
                                                                              
'best' calibration (6/20/96):                                                 
  offsets (nT):             O1 =    41.2                                      
                            O2 =     3.5                                      
                            O3 =    37.5                                      
                                                                              
  Coupling matrix (nT):   0.005252  -1.017174  -0.060191                      
                          0.984121   0.004677  -0.003778                      
                          0.000425  -0.060009   1.005252                      
                                                                              
scale factors (for converting eng. units to nT):                              
  gain   = 16384                                                              
  offset =     2                                                              
  matrix = 32767                                                              
                                                                              
Calibration Procedure:                                                        
                                                                              
  The Galileo magnetometer applies the onboard calibration to all data before 
  further processing, including transmission to the ground. In order to       
  apply an improved calibration, the onboard calibration must be reversed     
  to get back to 'sensor' data. First convert the onboard calibration factors 
  to real numbers by dividing by the various scale factors.                   
   1) To work in units of nanoTesla, divide the MAG vector in engineering     
      units by the offset scale factor. (s/c coordinates)                     
   2) Multiply the mag vector by the inverse of the scaled onboard            
      calibration matrix. (converts to sensor coordinates)                    
   3) Divide the MAG sensor data vector by the sensor gain factors.           
   4) Add the sensor offsets back to the sensor data.                         
  Now apply the improved calibration.                                         
   1) Subtract the improved sensor offset estimates.                          
   2) Multiply by the coupling matrix.                                        
  Data are now in spacecraft coordinates (spinning) in units of nanoTesla.