Solving the strip adjustment problem of 3D airborne Lidar data

Abstract

This paper proposes a contribution to the adjustment problem of airborne laser scanner strips. Based the comparison of each laser strips with a photogrammetric derived Digital Surface Model (DSM), and on the modeling of the discrepancies between these two data sets, the algorithm produces an homogeneous 3D deformation field. The measurements of these deformations is performed using a modified Hough transform and we search for the maximum of the accumulator whereupon we assign a probability of correctness. Depending of this probability, we estimate a global affine transform over the cloud of points. For transitivity properties, all strips are registered with regard to this DSM and therefore they all perfectly fit on overlapping areas. This fine registration is of importance for many applications, especially when fusionning photogrammetric data and lidar data for feature extraction. More generally, this method can be applied to any other sorts of 3D data and provides an efficient algorithm for matching 3D datasets