C Commands Summary

MiLLennium GPSCard SW Version 4.503/4.52 Command Descriptions Manual Rev 2 135

USERDATUM

This command permits entry of customized ellipsoidal datum parameters. Use this command in conjunction with

the DATUM command. The default setting is WGS84.
Syntax:
Example:

userdatum 6378206.4,294.9786982,-12,147,192,0,0,0,0

USERDATUM semi-major flattening dx dy dz rx ry rz scale

Syntax Range Value Description Default Example
USERDATUM -Command userdatum
semi-major min.
6300000.0
max.
6400000.0
Datum Semi-major Axis (a) in metres 6378137.000 6378206.4
flattening min. 290.0
max. 305.0 Reciprocal Flattening, 1/f = a/(a-b) 298.257223563 294.9786982
dx,dy,dz min. - 2000.0
max. 2000.0 Datum offsets from WGS84 in meters:
These will be the translation values between your datum
and WGS84 (internal reference)
0.000,0.000,0.000 -12,147,192
rx,ry,rz min. -10
max. 10 Datum Rotation Angle about X, Y and Z axis (radians):
These values will be the rotation between your datum
and WGS84 where a positive value indicates a clockwise
rotation and a negative value indicates a counter
clockwise rotation.
0.000,0.000,0.000 0,0,0
scale min. -10
max. 10 Scale value is the difference in ppm between your datum
and WGS84 0.000 0