A method to eliminate TDOA ambiguity based on FDOA and FDOA-rate

For eliminating ambiguity of time difference of arrival (TDOA) in radar passive location system, especially with a high pulse repetition frequency (HPRF), a novel method based on frequency difference of arrival (FDOA) and FDOA-rate is proposed in this paper. By using FDOA and FDOA-rate parameters, the radar emitter´s position can be roughly estimated in order to provide a direct calculation of TDOA solving its ambiguity. Furthermore, the location accuracy using FDOA and FDOA-rate is derived, and the constraint condition with no TDOA ambiguity is also presented. Simulations show that the proposed method can reduce the TDOA ambiguity effectively along with the extension of sampling time.