Fast bearing finding in non-cooperative passive detection

By using the approximate ARD surface in the detection space to estimate number, bistatic ranges and Doppler frequencies of targets, the target bearing for non-cooperative passive detection is estimated via the amplitudes of different array scanning beam received from the same target echo. It is proved that this method is nearly unbiased. The range of estimation variance and the highest theoretic precision are deduced. It indicates that the highest theoretic precision achieves Cramer-Rao bound when the beamforming with the rectangular weight. Simulation results validate the correctness and effectiveness of the method.