! Columbus supports keywords that allow you to define centering errors for different types 
! of observation sets. Once centering errors have been defined, they apply to all applicable 
! observations that follow in the file. You can turn off the settings at any time by 
! setting them back to zero.

! Centering errors are always entered in the active linear units.



! Example:

! Establish centering errors for a Hor Angle observation set.
!       AT Hor Cent;    AT Vert Cent;    TO Hor Cent;    TO Vert Cent;     BS Hor Cent
_C_HA;  0.003;          0.005;           0.002;          0.005;            0

! AT Hor Cent  = Horizontal Centering at Instrument
! AT Vert Cent = Vertical  Centering at Instrument
! TO Hor Cent  = Horizontal Centering at Foresight
! TO Vert Cent  = Vertical Centering at Foresight
! BS Hor Cent  = Horizontal Centering at Backsight

! Define some Hor Angle observation sets
_OBS_HA_SET;  A; B; D; 90.0000; 20.0; 88.0000; 25.0; 93.7500; 0.050; 0.0; 0.0
_OBS_HA_SET;  A; D; Z; 190.0000; 20.0; 98.0000; 25.0; 117.7500; 0.050; 0.0; 0.0

! Turn centering off for Hor Angle observation sets
_C_HA; 0; 0; 0; 0; 0





! Azimuth Observation Set
!         AT Hor Cent;    AT Vert Cent;    TO Hor Cent;    TO Vert Cent
_C_AZ;    0.003;          0.005;           0.002;          0.005




! Direction Observation Set
!         AT Hor Cent;    AT Vert Cent;    TO Hor Cent;    TO Vert Cent
_C_DIR;   0.003;          0.005;           0.002;          0.005




! Bearing Observation Set
!         AT Hor Cent;    TO Hor Cent
_C_BEAR;  HA;  0.003;          0.002




! Horizontal Angle Observation Set
!         AT Hor Cent;    AT Vert Cent;    TO Hor Cent;    TO Vert Cent;     BS Hor Cent
_C_HA;    0.003;          0.005;           0.002;          0.005;            0




! Delta North, East, Up Observation Set
!         AT Hor Cent;    AT Vert Cent;    TO Hor Cent;    TO Vert Cent
_C_NEU;   0.003;          0.005;           0.002;          0.005




! GPS Observation Set
!         AT Hor Cent;    AT Vert Cent;    TO Hor Cent;    TO Vert Cent
_C_GPS;   0.003;          0.005;           0.002;          0.005




! Height Difference Observation Set
!            AT Vert Cent;    TO Vert Cent
_C_HGTDIFF;  0.005;           0.005