1. A method of producing a geometrical representation of a plurality of referents in space, comprising a step of obtaining signals from a plurality of referents and a step of uti lising the signals in order to provide the geometrical representation of the referents, wherein the step of utilising the signals includes predicating that differences in the signals from the referents imply an actual distance between the referents, in accordance with a theory of spatial redundancy, predicating that the differences in signals are related to the actual distance between the referents by a monotonically increasing function, predicating that the differences (b) in signals implies an actual distance (a) between the associated referents, and utilising the signal differences (b) to determine a geometrical distance (g) for locators constituting the geometrical representation, wherein the geometrical distance (g) is a function of the actual distance (a).