Passive radar-based target localization through self-mixing processing and binary search minimization

Passive radar is a specialized form of the bistatic radar configuration in which a sensing system consists solely of appropriately designed receivers to take advantage of transmitters already operating in the target environment. These transmitters are termed illuminators of opportunity. Bistatic radar ranging requires knowledge of the time difference of arrival between the direct and target-reflected signals, the baseline length, and the direction of arrival. Furthermore, current localization methods involve matrix operations, adaptive thresholding, and triangulation. Generally, elliptical contours of constant range are formed for each range estimate, and the intersection of these ovals represents a localized solution. However, many solutions may exist – therefore introducing ghost targets. This paper presents a concise method of localization depending on the time difference of arrival resolved through self-mixing processing and range estimation via binary search minimization. This method allows for efficient target range determination without the occurrence of ghost targets. The mathematical derivation and scenario simulations are explored in this work and demonstrate the feasibility of this technique in space domain awareness applications.