3.9. Local Transformation
To calculate a local
transformation choose the Input > Coordinates
submenu and enter the coordinates and point numbers of the control points.
When
measuring the control points in the Input
> Measurements submenu, make sure to use the same point numbers as
entered before. Once you have measured your identical points, it is possible to
calculate a transformation. Choose the Calculate > Polar/GPS-Transformation submenu.
First choose the kind of transformations with the Transf > Change button.
To perform a standard local adjustment use a 3-Parameter-Transformation without
residual estimation.
The <Ctrl Pnt> button shows the
residuals in meters for the control points. To define a control point choose the button <Edit>
and click on the button CP.
Use the button <Calculate> to
start the transformation for all points orientated on the chosen station. The
differences to the known coordinates are shown.
The
calculated transformation affects the user coordinates of the current selected
station. It is saved with respect to the station and is applied for all
coordinates calculated out of measurements made on this station. GART-2000®
CE uses the
global 7-parameter transformation together with the projection chosen in Initial
> Constants > GPS and the local transformation chosen here.
For
a new station the old transformation cannot be applied. Optionally, a new
transformation can be defined.