GLRT-Based Adaptive Doppler Processing for HF Radar Systems

High frequency skywave and surface-wave over-the-horizon (OTH) radars are required to detect targets in the presence of powerful clutter and interference from man-made and natural sources. However, the received disturbances may be highly structured in the time domain (i.e. pulse-to-pulse) within the coherent processing interval (CPI). This provides scope for adaptive Doppler processing to enhance detection performance with respect to conventional FFT-based methods. This paper proposes a generalized likelihood ratio test (GLRT) based detector that not only possesses the valuable constant false alarm rate (CFAR) property invariant to disturbance scale-change, but also exhibits distinct advantages over the adaptive coherence estimator (ACE) and adaptive subspace detector (ASD) when unwanted signals are present. Here, we present the first experimental results for this detector in a HF surface wave radar Doppler processing application.