On the Estimation of Rigid-Body Transformation for Tls Registration

The paper presents some considerations on the estimation of rigid-body transformation which is the basis for registration and georeferencing in terrestrial laser scanning. Two main issues are afforded, which in the opinion of the author have been poorly investigated up until now. The first one concerns the analysis of the stochastic model of Least Squares estimation of the transformation. In standard practice, the control points used for parameter estimation are considered as equally precise. Here two different approaches for weighting observations in laser scan and ground control points are proposed and evaluated through a set of Monte Carlo simulations. The second aspect refers to the reliability analysis. In particular the estimation of a joint-adjustment including both geo-referencing parameters and geodetic network observations for the determination of ground control points is discussed and evaluated.