The Helmerttransformation is used to move the co-ordinates of the Digitizers in the Sollkoordinaten of the data bank. The transformation can carry out a translation, a rotation around small corners and a Skalierung. The Skalierung is carried out in X axis and Y axis with the same graduation. The transformation is based on an amount from points (at least two) from which the co-ordinates are in both systems bekann. They are called identical points. Practically The points whose Sollkoordinaten are in the data bank bekann e.g. the corner points of a plan, are digitized, after the plan on the Digitizer was fixed.
Attention: x is the high-level value, y is the legal value.
Given:
yAP, i
xAP, i Co-ordinates of the identical points in the old system
yNP, i
xNP, i Koorditanten of the identical points in the new system
yA
xA Co-ordinates of a point in the old system (before the transformation)
n Number of the identical points
In request:
yN
xN Co-ordinates of the point (yA, xA) after the transformation in the new system)
Calculation:
The main focus in the old system
The main focus in the new system
The transformation constants o and a.
an is the change of the graduation, o is the rotation.
