This study tackles the production of 3D realistic map databases for outdoor environments. An approach based on the fusion of heterogeneous 3D representations was studied. We propose a variant of ICP (Iterative Closest Point) based on an adaptive dynamic threshold and a RANSAC removing outliers process. An application of our approach was tested on two scenarios: a registration of point clouds obtained by a fixed terrestrial 3D Laser on a 2.5D data Digital Model of Surface (DSM), and the registration of point clouds obtained by a Mobile Mapping System (MMS) on DSM. The objective is to obtain coherence of a homogeneous 3D representation, which will be the input of the following processing step: 3D modeling. We treat various scenarios of registration which were specified; the algorithm exploits specific pre-processing dedicated to the studied use-cases.