C Commands Summary

118 MiLLennium Command Descriptions Manual

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 metres:
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 (sec of arc):
These values will be the rotation between your datum
and WGS84
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