Adaptive Detection of Wideband Radar Range Spread Targets with Range Walking in Clutter

In this paper, we address detection of range spread targets with range walking in partially homogeneous clutter, which is often encountered in wideband radar. By considering the target range walking effect, a target returns model is proposed that represents the relationship between Doppler frequency and range frequency. Based on this, a generalized matched subspace detector (GMSD) and a general adaptive subspace detector (GASD) are proposed in the frequency domain. Moreover, to eliminate excess integration loss introduced by the mismatched detection window size, two improved detectors are proposed in range domain. The theoretical analysis shows that the GMSDs are of a constant false alarm rate (CFAR) with respect to both the power and the covariance matrix of the clutter but that the GASDs are of a CFAR with respect to the clutter power and an approximate CFAR with respect to the clutter covariance matrix. Simulated experiments are carried out to verify the effectiveness of the proposed detectors.