PROJ Transformation Library

PROJ is an open source transformation library where the Norwegian Mapping Authority has contributed with transformations and source code.

Gemini Terrain has implemented this transformation library.

For transformations and conversions in PROJ, EPSG codes are used when transitioning between reference frames, datums and projections.

The library converts coordinates between the various official reference frames EUREF89, ITRF, NGO1948 and ED50. The program can also convert between plane, geographic and geocentric coordinates. This also includes conversion to and from the building and construction projection EUREF89 NTM.

The requirement for transformation is that the coordinate system/height system is defined with EPSG codes in Gemini.

Create Transformation

Procedure

1. Open the Gemini Terrain Settings dialog
2. Select General and Plan Transformations...
3. Click New... and select transformation type PROJ
4. Enter ID and description and select From coordinate system and To coordinate system

How to Transform?

Standard application layers and surveying application layers contain information about reference systems and can be transformed directly.

Procedure

1. Select application layers to be transformed
2. Go to Tools - Transform in plan... on the context menu in the vertical list field
3. Select the transformation set you want to use and click OK
4. The transformation is performed

For standard application layers, you can also transform data during import and export.