Wavefront Adaptive Sensing for Radar Spread Clutter Mitigation

In spatially inhomogeneous, Doppler-spread radar environments, adaptive processing is often precluded because neither the target wavefront is sufficiently known nor is signal-free training data available. This paper presents a new clutter mitigation method designed to overcome these challenges by combining minimum variance (MV) adaptive beamforming and blind source separation (BSS) for distributed sources. Wavefront adaptive sensing (WAS) is a hybrid adaptive beamforming approach which uniformly maximizes gain against clutter by avoiding MV signal cancellation due to mismatch at high SNR and poor BSS threshold performance at low SNR. Simulation results are presented for target detection in a multi-mode spread-Doppler over-the-horizon radar scenario.