Troposcatter OTH passive sensing with Cohen's class distribution based on an equal-slope Hough transform

The tropospheric scatter mechanism is potentially valuable for over-the-horizon (OTH) passive sensing, two limitations of this mechanism as large propagation losses and scattering fading diffusion are analyzed. Based on the diffusion properties, the received signals are analyzed with a bilinear Cohen's class distribution, of which the parameterization function (i.e. the kernel) is built from the diffusion coefficient to enhance the SNR. After that, target signals are focused in a parameter space by an equal-slope Hough transform (HT) with a priori information of the intra-pulse frequency interval, the focus-points can be effectively accumulated to detect the OTH targets.