Transformation from Lambert72 to Lambert 2008 in ArcGIS Pro

The Belgian Lambert 2008 projection system (EPSG: 3812) is based on the ETRS89 geodetic system. It integrates better across borders than the Lambert72 projection system. The Lambert 2008 projection is now established as a reference in accordance with the INSPIRE directive.

The Belgian National Geographical Institute provides to users on its website an NTv2 grid for the transformation of geographical data expressed in the Datum Belge72 (on which the Lambert72 projection system is based) to the ETRS89 Datum.

This transformation grid has been integrated by ESRI with their new version of ArcGIS software. However, they are not included with the default software. Grid files are compact, but including NTv2 grids for every country would make ArcGIS Pro too large. That’s why NTv2 grids are available as a separate, easy-to-install package, the “ArcGIS Coordinate Systems Data” module.

To find this module, go to My Esri. You can find this module under the download tab. The “ArcGIS Coordinate System Data” module is to be downloaded from the for ArcGIS Pro related modules, under “Data and Content”. This module installs like any other module in ArcGIS Pro.

You need to consider the installation type of ArcGIS Pro (determined by the installation settings, see https://pro.arcgis.com/pro-app/get-started/arcgis-pro-installation- administration.htm).

If it’s a “per user” installation (this is the default installation option, parameter ALLUSERS = 2), you will need to install the “ArcGIS Coordinate Systems Data for ArcGIS Pro Per User Install” module.

If it’s a “per machine” installation (parameter ALLUSERS = 1), the “ArcGIS Coordinate Systems Data” module must be installed.

If you do not need all transformations, you can choose to install part of the contents of this module during the installation process. To do so, click on the icon next to the specific component:

After installation, the NTv2 transformation from Datum Belge72 to Datum ETRS89 is available under the name “Belge_1972_To_ETRS_1989_3”.

Below an example in ArcGIS Pro:

If you have any questions about this topic or need help with the transformation from Lambert72 to Lambert 2008 in ArcGIS Pro, please feel free to contact info@esribelux.com.