Direction finding in frequency-modulated-based passive bistatic radar with a four-element adcock antenna array

The Adcock antenna array is widely used in electronic warfare for direction finding of emitter sources. However, in frequency modulated (FM)-based passive bistatic radar (PBR) the traditional Adcock antenna-based direction finding methods cannot work well because weak target echoes are embedded in the background of strong direct signals, multipath and clutter echoes. A method using a four-element Adcock antenna array is developed for horizontal plane 360° target direction measurements for FM-based PBR. By using numerical simulations, the performance of the proposed method is studied for both single and multiple targets, and finally its effectiveness is demonstrated for real data.