Photo: Stéphane Couderq

3D city model of the Canton of Geneva, Switzerland 

In July 2008, the canton of Geneva has awarded COWI to generate a detailed 3D city model of the whole canton and to deliver the data for their GIS. This major 3D project includes approx. 76.000 buildings on about 245 sq. km and will be performed within approx. 10 months.

Use of the client’s existing aerial images
COWI will use existing aerial images taken by a Vexcel camera as well as the official building footprints from cadastral survey. The 3D city model will be derived using photogrammetry and strong in-house developed 3D capturing and editing software tools.

Photo: COWI A/S

Highly sophisticated 3D model for GIS

The 3D city model that COWI produces is not only highly detailed and accurate, but also fulfils major requirements by the client to use the data in its GIS. The 3D data is therefore combined with the existing cadastral 2D footprints and split accordingly to have a consistent 3D vector model that fits to the existing 2D footprints.

Overhanging roofs are generated, geometric attributes like volume, inclination etc. calculated automatically and stored along with attributes coming from the existing 2D dataset.
The 3D model will be delivered in three coordinate systems (MN03, MN95, WGS84) in the geodatabase format (ESRI).

Applications3D city models are powerful datasets with various applications like GIS analysis, urban planning, homeland security, tourism, web-based 3D visualization and many more.