AUTOMATIC IMAGE-BASED 3D RECONSTRUCTION STRATEGIES FOR HIGH-FIDELITY URBAN MODELS – COMPARISON AND FUSION OF UAV AND MOBILE MAPPING IMAGERY FOR URBAN DESIGN STUDIES

Abstract

Modelling environments for urban projects often involve virtual reconstructions of existing urban areas where generalised city models are not sufficient. The use of photogrammetry with aerial imagery from UAVs on the one hand, and imagery from street-level mobile mapping systems on the other, has advanced significantly in recent years. However, there are limitations when these two imagery types are used separately.The main contribution of this paper is an end-to-end solution for creating large-scale and complex reality-based mesh models of urban environments. We outline a novel image-based 3D reality capturing process by combining street-level imagery from a backpack multi-camera mobile mapping system and nadir and oblique UAV imagery. This reconstruction is based on dense multi-view image matching method. A use case is presented with a goal to reconstruct an area for an urban project which aims to introduce an elevated cycle highway to facilitate traffic. The investigated area has a size of 0.64 square kilometres and is in the city of Basel in Switzerland. The MMS and UAV images were all oriented in a single photogrammetric project. Several reconstructions with different configurations were investigated and the results of the successful reconstruction with a geometric accuracy of a few cm are presented.