Airborne Asynchronous TDOA Based on Critical Area

Exploiting the time different of arrival to passive detection is becoming a promising issue in passive surveillance. Time different of arrival can resolve the location of the target by using time difference of arrival from multi-base station in the same radar wave beam. The time different of arrival that the base stations are not in the same wave beam is rarely studied. This paper puts forward asynchronous time different of arrival and builds critical area to solve the location problem which the base stations are not in the same wave beam. Critical area is relative area in which all station are just right in the same radar wave. By further analyzing this area, the Euclidean distances of all aircraft stations are obtained and are used this information to solve the asynchronous time different of arrival. What is more, the analysis of its error is given. Simulation shows that the asynchronous time different of arrival suits for sparse formation of aircraft, and it can get better calculating precision.