Genetic Algorithms for PRI ambiguity resolution in Passive Emitter Tracking

Passive emitter tracking (PET) is an accurate technique to localize an emitter through time difference of arrival (TDOA) multilateration by a network of sensors. It suffers from pulse repetition interval (PRI) ambiguity when two successive pulses are closer than the distance between the receivers. The problem can be undertaken by minimizing an error function (X²), and ambiguity can be solved by using coarse direction of arrival (DOA) information; but X² becomes a very complex function of position for low PRI (airborne radars). Traditional approaches to solve ambiguity can be time consuming. An alternative approach is presented which exploits the characteristics of genetic algorithms (GA), suitable for the optimization of particularly complex functions. This technique becomes more efficient than the standard methods for low PRI.