Sensor registration in ECEF coordinates using the MLR algorithm

The Maximum 'Likelihood Registration (MLR) algorithm' has been recently proposed for spa- tial alignments of multiple, possibly dissimilar (active and passive) sensors. This paper applies the MLR algo- n'thm to register sensors in the Earth-Centred-Earth- Fixed coordinate system, and derives the corresponding theoretical Cram&-Rao bound for this application. The problem is relevant in the context of wide-area surveil- lance with the &ed-site radars, where the stereographic projection on a two-dimensional regional plane intro- duces errors.