The 1m DSM is obtained by interpolation in Lambert 2008 of the raw height data regrouping the source data, in Lambert 72 and at 1m resolution, of the Flemish and Walloon regions.

The source data used for the production of this DSM are the DSM at 1m resolution of the regions: those of the AIV (ex-AGIV), for the Flemish region and those of the SPW, for the Walloon region.

These source data are collected and processed to obtain a homogeneous and regular grid with a point every 1m in X and Y indicating the height of the land surface.

The two regional organisations providing their product in Lambert 72, the IGN reprojected the data into Lambert 2008 and carried out an interpolation in order to obtain a product with round coordinates and then assembled them so that the DSM 1m product thus created covers the entire Belgian territory"The product called “DSM1meter”, in short DSM 1m, indicates the height of the surface of the Earth, i.e. the ground or any other permanent and visible landscape element (vegetation, construction, …) compared to the Belgian zero level (fictitious zero-D of Uccle). In other words, it is the orthometric height, commonly known as height.

The source data used to produce this DSM are the DSM at a 1m-resolution from the regions: data from Digitaal Vlaanderen (former AIV and former AGIV) for the Flemish Region, data from the SPW for the Walloon Region and data from Paradigm for the Region of Brussels-Capital. These regional DSM are derived from the clouds of points obtained during the LiDAR campaign (flight of 9 October 2021 for Brussels, from 19 February 2021 to 5 March 2022 for Wallonia and from 20 February 2013 to 20 April 2015 for Flanders).

These source data are gathered and processed in order to obtain a homogeneous and regular grid with every meter a point in X and Y indicating the height of the surface level of the Earth.

As the Flemish and Brussels regional bodies deliver their products in Lambert 72, the NGI reprojected those in Lambert 2008 and achieved an interpolation in order to obtain a product with round coordinates, and then gathered them with the product of the Walloon Region (already in Lambert 2008) so that the newly created DSM 1m-product covers the whole Belgian territory.

During the creation of DSM 1m, the highest priority is to get a complete coverage.

This priority is an important requirement for internal applications oof the NGI and for most external customers.

Besides, the availability of DSM 1m as a standard product (point grid every 1m in XY) in a generic format (gdb raster file) that can be used by all the software packages is a remarkable asset for internal and external applications.