HF RCS of Small Boat Displacement in the Ocean

We present a numerical modelling approach for determining the HF radar cross-section of a volume displacement in the ocean surface. This displacement, for example, might be from a non-conductive wooden-hulled boat with no metal structure or fittings. Such a vessel typically has too small a radar cross-section to be detected considering only the scattering properties of the boat in isolation. Our modelling technique is approximate but indicates wooden, or other non-conductive material boats may be detectable by skywave radar in some instances, solely due to their displacement in the ocean. Our results suggest new radar management strategies to improve the likelihood of detecting these targets. However, we continue to require the preferred ship detection criteria of low sea-state and low doppler-spread ionospheric propagation conditions. We also assume the boat is moving at speed and heading combinations such that the target Doppler is separated from the ocean first-order Bragg scatter.