Suppression of Weather Clutter by Means of Log-Normal/CFAR Circuit Modified from CA LOG/CFAR Circuit

SUMMARY We have observed weather clutter including targets (ships) using an S‐band radar with a frequency of 3.05 GHz, a beamwidth of 1.8°, and a pulse width of 0.5 μs. To investigate weather clutter amplitude statistics, we introduce the Akaike information criterion (AIC). We have found that the weather clutter amplitudes obey log‐normal, Weibull, and log‐Weibull distributions with shape parameters of 0.329 to 0.477, 4.40 to 4.55, and 11.93 to 16.44, respectively, for data within the beamwidth of an antenna. We propose the log‐normal/CFAR circuit, modified from a cell‐averaging (CA) LOG/CFAR circuit. It is found that weather clutter is suppressed with improvement of 51.58 dB by log‐normal/CFAR.