The 3D Helmert transformation is a frequently used method in geodesy

to produce transformations between different Cartesian coordinate systems:

X

where X

X = initial coordinate vector

T = translation vector

R = rotation matrix including r

r

s = scale factor

Seven parameters are required for this kind of transformation

and can be calculated from a set of at least three point correspondences.

helmparms3d (a free command-line tool) reads two ASCII point-files and

calculates all necessary papameters for Helmert transformation.

All parameters are written to an ASCII file for further computations.

Syntax:

$ helmparms3d src_points.txt dest_points.txt outfile_name.txt