Propagation speed free emitter location finding using TDOA

The location of an electromagnetic, acoustic or seismic source can be determined by spatially separated synchronized receivers. To locate the target, hyperbolic lines of position are defined by using the time differences of arrival (TDOA), between these receivers. Then the target is positioned at the intersection point of these lines. In literature, most of the TDOA based methods assume that the propagation speed is known. Whereas, the propagation speed depends upon the elasticity and the density of the medium and in most cases it is unknown. For the overdetermined systems, in very few works, target position and propagation speed are estimated jointly. In this paper, different from the published studies up to now, a novel method based on TDOA but independent of the speed of propagation is proposed. In this proposed method, the propagation speed is removed by proportioning the time differences each other and the target is positioned using particle swarm optimization with the obtained time difference of arrival ratio. Simulation results prove the validity of the proposed novel method.