Illuminator of opportunity selection for passive radar

Passive radar can obtain performance benefits by using multiple receivers and multiple illuminators of opportunity (IOO). However, employing a large number of IOOs is costly in terms of hardware. Thus, it is sometimes necessary to limit the total number of selected IOOs. The IOO selection scheme for maximizing target detection performance is studied in this paper, under the assumption that the number of IOOs that can be selected at each receiver is limited. An IOO selection algorithm based on maximizing the Kullback-Leibler (KL) distance is presented, which requires much lower computational complexity compared with the exhaustive search method and is shown to lead to a detection performance that is close enough to that of the optimal selection.

1. Introduction

Passive radar employs the illumination offered by existing signals to avoid transmitting energy. FM radio signals [1], television signals [2], WIFI signal [3], and Global System for Mobile communication (GSM) signals [4] have been used to detect [5] and track [6] targets of interest and estimate their parameters [7]. As no transmitters are required, a passive radar has obvious advantages over active radars, which include reduced cost and complexity.