Investigation into the Passive Detection of Point Targets Using FM broadcasts or White Noise

摘要

Over the past three years, researchers at the University of Washington have been developing a multistatic radar system that uses commercial FM radio broadcasts to detect plasma waves in the ionosphere. This research has shown that the short autocorrelation times of FM broadcasts make it possible to achieve good range and doppler resolution despite the continuous operation of the transmitter However, because of the great distances of ionospheric targets (>600 km) most research has focused on a multistatic system consisting of a reference receiver and another receiver isolated from the direct broadcast signal by the Cascade Mountains. Although some research was done on a bistatic system, it was quickly seen that the clutter limited dynamic range would make the observation of plasma waves very difficult if not impossible. This analysis though did not rule out the detection of aircraft at distances close to the receiver-transmitter baseline. In fact, the first detection using FM broadcasts was that of a bistatic detection of an aircraft displaced 1.5 km from the baseline 1.