Passive Emitter Localisation Using TDOA and FDOA Measurements from UAV

Abstract

This paper addresses the joint time difference of arrival (TDOA) and frequency difference of arrival (FDOA) measurements for a passive emitter location using cross ambiguity function (CAF). The TDOA and FDOA measurements obtained from moving unmanned aerial vehicles (UAVs) are sent to the ground station for finding the peak of the CAF using grid optimization technique. These are then directly mapped on to the surface of the earth to locate the position of the static emitter. Conventional techniques, on the contrary, uses the method of least squares or maximum likelihood for position estimation which is computationally intensive. Proposed method is able to localise the emitter accurately even at low signal to noise ratio at the receiving stations. As the receivers are moving in nature, the emitter and reciever geometry keeps on changing. Due to this, during simulations, multiple signal lengths and various distance between emitter and receiver are taken into consideration for measuring the location accuracy. In addition to it an offset in receiver position and velocity is also introduced and the accuracies are compared. Extensive numerical experiments validate the effectiveness of the proposed method.