Two approaches for dense DSM generation from aerial digital oblique camera system

In recent years, in photogrammetric field, have been developed technologies, which consist of multi digital oblique camera, able not only to observe the same target from different angles, but also to determine, thanks to appropriate dedicated software, the geometry. Of particular interest is the new oblique camera system Leica RCD30 that combines vertical (nadir) and oblique cameras according to the “Maltese cross” characteristic scheme. The purpose of this work is to verify the potential of the oblique imagery to provide dense point clouds to realize Digital Surface Model (DSM) to high resolution, where for high-resolution model is meant a representation of the observed scene with a ground sample distance (GSD) of less than 10cm. The dense Digital Surface Models are obtained through two different approaches, one that derived from photogrammetric reconstruction based on graphic processing units (GPU) technique and multi-core CPUs, the other from so-called Structure from Motion (SfM). To analyse the quality both of acquisition systems that the model surface obtained from images, a case study on the Nöllen (Switzerland) area is presented.