On the Use of HF Surface Wave Radar in Congested Waters: Influence of Masking Effect on Detection of Small Ships

In this paper, we assess the capability of a high- frequency surface wave radar (HFSWR) to detect a small fast boat moving behind a ship, the dimensions of which are comparable to the wavelength. We show that, in the HF-band, the scattered field in the shadow region of the large ship is significant enough to induce strong coupling between the two vessels. This results in fluctuations in the radar cross section (RCS) values of the small boat of about 12 dB at 10 MHz, for instance. We also introduce a complete simulation tool to account for the environment and, thus, to be able to simulate real scenes. We have validated these results through anechoic chamber measurements, with two different masking vessels and three different masked ships. The measurements have shown both the low-attenuation results and the RCS fluctuations.