Ronald Mahler's Probability Hypothesis Density (PHD) provides a promising framework for the passive coherent location of targets
observed via multiple bistatic radar measurements. We consider
tracking targets using only range measurements from a simple
non-directional receiver that exploits non-cooperative FM radio
transmitters as its "illuminators of opportunity." A target
cannot be located at a single point by a particular transmitter-receiver pair, but rather it is located along a bistatic range ellipse determined by the position of the target relative to the receiver and transmitter. Target location is resolved by using multiple transmitter-receiver pairs and locating the target at the intersection of the resulting bistatic ellipses. Determining the intersection of these bistatic range ellipses and resolving the resultant ghost targets is generally a complex task. However, the PHD provides a convenient and simple means of fusing together the multiple range measurements to locate targets. We incorporate signal-to-noise ratios, probabilities of detection and false alarm, and bistatic range variances into our simulation.