To create a Helmert transformation
Local transformation support is available only when the Advanced Geodetic option is enabled in the Cogo settings screen of the job properties.
- Tap
and select Cogo / Adjust / Transformations.
- Select Manage local transformations. Tap Next.
- Select Create new transformation. Tap Next.
- Set the Transformation type to Helmert and then enter the Transformation name.
- Set the Scale factor type to one of the following:
- Free – The computed best fit scale factor is used in the transformation.
- Fixed– The scale factor you enter is used in the transformation.
- Set the Vertical adjustment to one of the following:
- None – No vertical adjustment is carried out.
- Constant adjustment only – The average vertical correction computed from the elevations of the point pairs is used for vertical adjustment in the transformation.
- Inclined plane – A vertical correction plus a best fit correction plane is used for vertical adjustment in the transformation.
- Tap Next.
- Tap Add to select the Grid point name and Local grid point name pairs of points and then set the Use field to one of the following:
- Off – Do not use this point pair in the computation of the transformation parameters.
- Vertical only – Use this point pair only in the computation of the vertical adjustment parameters.
- Horizontal only – Use this point pair only in the computation of the horizontal adjustment parameters.
- Horizontal & vertical – Use this point pair in the computation of both the horizontal and the vertical adjustment parameters.
- Tap Accept to add the pair to the list and then tap Add again to add more pairs of points.
- To view the result of the transformation, tap Results.
- Tap Store.
If you change the coordinates of a point used to define a Helmert transformation, you must recompute the Helmert transformation the new transformation to use the new coordinates.