DTM extraction in urban areas: a detailed comparison of methodologies, algorithms and results

In this paper we propose a comparison of the most important digital terrain model extraction techniques proposed in urban environments. In particular, we focus here on those based on digital signal processing applied to LIDAR data and on stereo photogrammetry. To this aim, we start from a data set composed by LIDAR and photo acquisitions over the town of Pavia, Northern Italy, and apply suitable DTM algorithms. Our investigation aims to provide a way to exploit both data sets. We were able to provide a complete DTM of Pavia with a very small degradation of the original measurements, as shown by a comparison with extremely precise ground control points