Range-Angle Localization of Targets by A Double-Pulse Frequency Diverse Array Radar

Phased-array radar is widely used in localizating non-cooperative targets, but the range and angle of targets cannot be directly estimated from its beamforming output due to an inherent range ambiguity, i.e., two-dimensional localization of noncooperative targets cannot be obtained directly from conventional linear phased-array radar beamforming peaks. This paper proposes a simple range-angle localization of targets by uniform linear array (ULA) double-pulse frequency diverse array (FDA) radar. The FDA transmits two pulses with zero and non-zero frequency increments, respectively. The azimuth angle and slant range of targets are then estimated directly from the beamforming output peaks. This approach can be interpreted as detecting the targets in angle dimension and then localizing them in range dimension by properly choosing the frequency increment. Moreover, multiple FDA radars can work as netted radar networks, in which distinct frequency increments or orthogonal waveforms are employed. The localization performance is examined by analyzing the Cramer-Rao lower bound (CRLB) and numerical mean square error (MSE). The effectiveness is demonstrated by simulation results.