User-Aided Global Registration Method using Geospatial 3D Data for Large-Scale Mobile Outdoor Augmented Reality

Accurate global camera registration is a key requirement for precise AR visualizations in large-scale outdoor AR applications. Existing approaches mostly use complex image-based registration methods requiring large pre-registered databases of geo-referenced images or point clouds that are hardly applicable to large-scale areas. In this paper, we present a simple yet effective user-aided registration method that utilizes common geospatial 3D data to globally register mobile devices. For this purpose, text-based 3D geospatial data including digital 3D terrain and city models is processed into small-scale 3D meshes and displayed in a live AR view. Via two common mobile touch gestures the generated virtual models can be aligned manually to match the actual perception of the real-world environment. Experimental results show that - combined with a robust local visual-inertial tracking system - this approach enables an efficient and accurate global registration of mobile devices in various environments determining the camera attitude with less than one degree deviation while achieving a high degree of immersion through realistic occlusion behavior.