The effects of sea clutter on the performance of HF Surface Wave Radar in ship detection

Abstract

This paper presents a study of the effects of sea clutter on the performance of HF surface wave radar (HFSWR), operating in the band between 3 and 5 MHz, in the detection of two classes of ships: large freighters with gross registered tonnage (GRT) in the order of several tens of thousands of tons and small vessels with a GRT of about 1000 tons. The radar returns from both large and small ships are estimated from the measured returns from the Canadian Coast Guard Ship (CCGS) Teleost, based on the differences of their radar cross section (RCS) estimated in [10]. The estimated returns are then extrapolated in range using the propagation attenuation calculated for the sea condition under which the measured returns were obtained. These extrapolated returns were compared with the sea echoes measured from the same radar to assess the detection capability of the radar. The conclusions of the study are that, in the detection of large ships, the radar performance is independent of sea state, but in the detection of small ships, the radar performance is dependent on sea state. It is shown that if a radar employing conventional linear beamforming methods is to maintain the detection capability for the small ships, then the aperture of the receive array cannot be reduced from its current value.