AUXILIARY PARAMETER DEFINITION RECORDS

Auxiliary parameters are used to solve for systematic errors that can occur in survey observations. For example there may be a scale difference between two sets of distance observations or a scale difference between 2 different groups of GPS measurements. The use of auxiliary parameters allow for the solution of the random and systematic errors at the same time.

The auxiliary parameters are defined by:

1. Explicitly by the user
   • Distance scale and constant values
   • Azimuth orientation
   • Coordinate system translation parallel to x, y and z axis
   • Coordinate system rotations about x, y and z axis
   • Coordinate system scale

2. Automatically (internally) by the program
   • Direction set orientation
   • Inertial Survey scale
   • Inertial Surbey orientation

Note: The code 94 record is used to define the auxiliary parameter in the BLKCORD file and to identify the auxiliary parameter associated with a particular observed set of coordinate observations in the INTCOBS file. Distance and azimuth auxiliary parameters are identified using the Sigma record

Sample records

      COLUMN    CONTENT

        1       Blank

        2-3     Code : 8 Junction auxiliary parameter record
                       94 Auxiliary parameter

        4-6     Type - used to identify a class of observations
                        DIS - Distance
                        AZI - Azimuth
                        DOP - Doppler
                        GPS - Global positioning System
                        LBI - Long Baseline Interferometry 
                        PEQ - Position EQuation
                        PRN - Partial reduced normal
                        
        7-15    Auxiliary parameter number used to associate the data on this
                record with data on other records 

        16-30   Additional identification
         
        32-35   Type of parameter
                        Distance
                          CS   - Constant correction
                            PR - Proportional correction (enter "PR" starting in column 34)
                        Azimuth
                          ORAZ - Orientation
                        Coordinate system parameters 
                          TRAX - Translation parallel to the X azis
                          TRAY - Translation parallel to the Y azis
                          TRAZ - Translation parallel to the Z azis
                          ROTX - Rotation about the X azis
                          ROTY - Rotation about the Y azis
                          ROTZ - Rotation about the Z azis
                          SCPR - Scale correction
                        
                        Note: Translation parameters are not defined 
                        for position difference observations
                              
        40-44   Optional initial value for distance and azimuth parameters
                Used in BLKCORD to establish a value other than 0.0