A reliable Doppler-based solution for single sensor geolocation

This paper examines the ability of particle filters to provide accurate Doppler-based frequency of arrival (FOA) geolocation of radio frequency (RF) emitters. Most existing non-differential Doppler geolocation techniques simplify their geolocation solution by assuming that the emitter´s carrier frequency is unknown but stable over the course of the triangulation. This assumption is often violated by today´s commercial devices whose applications allow for significant carrier frequency drift, with the result of erroneous FOA solutions. The proposed approach uses particles to discretely represent a state´s hypothesized emitter location and conditionally updates the particle´s associated frequency drift based on that location and the observations. The performance of this approach is examined for the case of a relatively slow-moving unmanned aerial vehicle (UAV). The results show it is significantly more accurate and robust than Newton´s iterative gradient descent techniques, and closely approaches the FOA Cramer-Rao lower bound (CRLB) for location estimation.