THE EFFECT OF SEA STATE ON THE RCS OF A SHIP

摘要

This paper concerns the effect of sea state on the radar cross-section (RCS) of a ship. Reflections from the sea are taken into account using rough surface reflection coefficients. The effects of sea state and elevation angle of the radar are determined. For sea state 0, sea reflections need to be taken into account. For sea state at other levels, its effect is dependent on the elevation angle. At close to grazing angles and low sea states, sea reflections contribute substantially to the total RCS and hence need to be considered. At close to grazing angles but high sea states, the effect of the sea reflections becomes minimal, and the total RCS approaches that of free-space RCS. At slightly higher elevation angles, for example at only 10° above the horizon, the effect of a nonzero sea state is very significant. Even at low sea state levels of 1 or 2, the RCS of the ship is already very similar to the RCS in free space. Thus for higher elevation angles the sea surface can be ignored for all sea state levels other than 0.