This is a close relative of the Helmert transformations. Instead of rotating about the standard axes passing through the origin of the coordinate system, though, it rotates about a set of axes parallel to those but instead passing through an arbitrary point specified in the control parameters. It uses approximate position vector rotation (following the formula described in EPSG guidance note 7, section 2.3.5). This approximation will only produce desirable results if the rotation angles are relatively close to zero.
The "MolodenskyBadekas" DatumShift has the following Parameters:
|
Parameter Name |
Parameter String |
Units |
|
X Translation |
dx |
|
|
Y Translation |
dy |
|
|
Z Translation |
dz |
|
|
X Rotation |
rx |
|
|
Y Rotation |
ry |
|
|
Z Rotation |
rz |
|
|
X Coordinate of the point about which the coordinate reference frame is rotated |
xp |
|
|
Y Coordinate of the point about which the coordinate reference frame is rotated |
yp |
|
|
Z Coordinate of the point about which the coordinate reference frame is rotated |
zp |
|
|
Scale Factor |
k |