Basingstoke 3D City Model

Skeye was asked to generate a 3D mesh of the city centre of Basingstoke in the United Kingdom. Photogrammetry was selected as the methodology whereby the 3D geometry of objects can be derived from a series of overlapping aerial images. The images were captured using a dual camera system from a manned aircraft. Two cameras are mounted at an offset whereby one looks straight down and the second at an oblique angle of 40 degrees. Normally aerial imagery is flown in a series of parallel strips but with this camera system the data is captured in flying a circular pattern. This enables the oblique camera to view objects from all different sides. For the 3D generation of a mesh it is important to capture imagery of the facades as well as the straight down images. The average resolution of the images was 6 cm.

3D city model with photogrammetry and aerial imagery

View the online interactive model through this link 

In total 900 images were captured that were used for the modelling in combination with ground based measurements with a GPS. The photogrammetry method will derive a 3D coordinate (X, Y and Z) for as many image pixels that are recognised in adjacent overlapping images. The result is a very dense cloud of points with around 100 points per square meters. A small amount of noise cleaning was required to create a clean and crisp 3D mesh.

The dense point cloud was used to create a 3D mesh. In this process the points are joined in such a manner as to create triangles. These triangles are subsequently coloured with the imagery. The end result was checked with independent ground measurements and demonstrated an average accuracy of 4cm.

3D city model photogrammetry and aerial imagery