3D mapping of buildings with SAPPHIRE

An experimental radar system is described that is designed to determine a building map in three dimensions by driving past the building with the radar mounted on a vehicle. The radar system, SAPPHIRE, produces full polarimetric reflectivity data in three dimensions with a voxel resolution of <0.5 m in each direction at 10 m distance. SAPPHIRE uses SAR in the driving direction, focused beam forming and MIMO in the vertical direction and FMCW radar in the range direction. The reflectivity data allows interpretation of specular and diffuse scattering behaviour and polarimetric behaviour of the scattering returns. In this paper, we describe the system design, component performance and system calibration. We also present building measurement results with the system mounted on a rail, discuss imaging and mapping methods and show the potential of SAPPHIRE for 3D mapping of buildings.