1. A method for classifying range profiles, comprising: (i) generating, for each in a set of objects of interest, a probabilistic model representing, for one or more different orientations of the object, possible sequences of distances between features of the object selected as being likely to result in distinct peaks in range data for the object, wherein the possible sequences of distances are derived from a first probabilistic representation of each said selected feature; and (ii) classifying a given range profile by deriving an observed sequence of distances from the spacing of distinct peaks in the given range profile and by calculating, for each of one or more probabilistic models generated at step (i), the probability that the model generates the observed sequence of distances, the object whose model generates the observed sequence with the greatest probability being associated with the given range profile.