Displaced Phase Center Antenna Processing For Airborne Phased Array Radar

Clutter suppression is paramount to detect slow-moving ground targets by an airborne radar. Ground clutter in the case of airborne radars is not centered on zero Doppler frequency due to the mobile radar platform, making the detection of slow-moving targets difficult. These targets appear very close to the main lobe clutter in the Doppler dimension. Thus, the main lobe ground clutter competes with the slow-moving targets raising the minimum velocity at which targets can be detected. Conventional radar signal processing methods can be used to filter out the clutter but at the cost of eliminating the signals of interest. In this paper, Displaced Phase Center Antenna (DPCA) concept has been utilized to suppress clutter for an airborne phased array radar. DPCA is a nonadaptive technique that eliminates clutter by electronically shifting the phase center of antenna array and subsequent subtraction of successive pulses. The benefit of DPCA lies in its simplicity and computational efficiency. DPCA algorithm extenuated clutter and increased the probability of detection of slow-moving targets. With DPCA processing, we were able to detect targets with velocities as low as 5 m/s.