An application of the Least Squares 3D algorithm for territorial monitoring and control

In this contribute we propose an application of a new algorithm for least squares matching of overlapping 3D surfaces that we sampled point by point using a terrestrial laser scanner. The studies on the absolute orientation of stereo models using DEMs as control information are known as DEM matching. The proposed method estimates the transformation parameters between two (or more) fully 3D surface patches and minimizes the Euclidean distances instead of Z-differences between the surfaces by least squares. The application in question is aimed, in the study of deformations of mountain areas, as well as test the TLS applied to a hilly area. For this purpose, it was also tested using the algorithm LS3D “Least squares 3D surface matching” that allows both the registration of point clouds produced by scans carried out without using targets but, overall, the estimate of deformations that in this case, compared to other methods, is done directly on the basis of the two data sets acquired in two different eras.