Detailed 3D Maps for the City of Brussels
Nowadays city stakeholders (companies, inhabitants, urban planners, city agencies etc.) have an increasing need to plan, view and simulate various aspects of the environment, weather, growth, and density of a city. The issues that require cities consider 3D models include shadow or noise impact, wave propagation, a line of sight analysis, urban planning, flood analysis, etc. Only with detailed, immersive visualizations and maps, can stakeholders truly get a picture of how these various dynamics affect the city.
The Centre of Informatics for Brussels Capital Region (CIBG) needed a detailed 3D model of buildings in the city of Brussels to accurately model the mobile phone signal reach and penetration throughout the city. With a model, the CIBG could determine if and where additional telecommunication antennas were needed.
For the required level of detail, simple block models would not suffice. CIBG needed detailed and accurate roof structures to adequately model signal wave penetration and come up with the best location to place antennas. The city engaged Avineon to create a process to integrate various source data format including vector data, Digital Terrain Models (DTM), ortho-photos, stereo-imagery and Light Detection and Ranging (LiDAR) data into an immersive 3D model of the entire region comprised of over 250.000 buildings and over 200 bridges.
Using newly acquired aerial images, Avineon first updated the 2D maps which served as a basis for the 3D model. All differences between vector data and the aerial images were identified, marked and sent to a photogrammetry team that did the update via stereo-restitution. This resulted in an up-to-date 2D base map.
In a multi-step process, Avineon then created 3D building footprints, perfectly aligned with the updated 2D map, and corresponding to the height of the Digital Terrain Models, as well as detailed roofs and walls. For most buildings, Avineon developed a semi-automatic process based on the LiDAR data, which was acquired at the same time as the aerial images that were used for the 2D Map updates. For modeling landmarks and complex buildings such as churches, unique skyscrapers, and sports stadiums, Avineon used manual modeling techniques based on their expertise in stereo-restitution.
Though not part of the scope of the work with CIBG, Avineon could have also used oblique image integration to create additional texture of buildings in and around the city. This could eventually allow a city add a level of immersion that accounts for detailed views of various scenarios and simulations but this was ultimately unnecessary for CIBG’s study.
With a comprehensive strategy, Avineon was able to deliver a rich 3D model of the city of Brussels to the CIBG for their specific purposes. The model was also made available for public and private use for city stakeholders of Brussels.
To see maps for yourself and read more on the project, click to go to the article in LiDAR Magazine.