UAV Team Formation for Emitter Geolocation

In this paper we study a scenario in which uninhabited aerial vehicles (UAVs) are tasked with locating a group of active emitters. The time difference of arrival (TDOA) technique is used by the UAVs to geolocate the active emitters. As TDOA requires at least three UAVs to perform geolocation, an algorithm to team three or more UAVs and task this team to geolocate an emitter is required. We discuss two approaches for teaming the UAVs, which we have developed and tested via simulation. The first approach is a simple heuristic that assigns the closest three UAVs to the highest priority emitter. This approach was simple and efficient to run, but improvements in performance could be made. Because TDOA works best when the UAVs are angularly separated evenly around the emitter, the next teaming algorithm developed takes into account the geometry between all UAVs and emitters. It assigns a cost for each UAV team and emitter combination based on the current angular separation of the UAVs around an emitter, and by how much each UAV team can perfect its geometry in a given time period. Two search techniques are explored, which search the solution space for efficient solutions. Results from simulation tests of the two approaches indicate that the second algorithm on average geolocates the emitters in the simulation faster than the heuristic approach, and provides an efficient solution to this UAV teaming and allocation problem.