Emitter locating using time-difference-of-arrival (TDOA) techniques

The present invention provides a method of selecting receiving pairs from a set of at least three receivers that may be used to localize an emitter. This involves identifying the set of at least three receivers to be used to localize the emitter. An isochron may be developed for each receiver pair wherein each isochron has a finite width. The intersection of two isochrons creates an uncertainty parallelogram. When the intersection of two isochrones is substantially orthogonal or subtends a relatively large angle, uncertainty based on the intersection angle is minimized and uncertainty becomes primarily a function of isochron width. To determine acceptable or best receiver pairs to be used, the intersections of each isochron pair may be analyzed. The uncertainty parallelograms and intersection angles are compared for each pair of intersecting isochrons. Then, receiver pairs that produced the isochrons that result in a reduced or compact uncertainty parallelogram may be selected.