Modified Two-Scale Model for Low-Grazing-Angle Scatteringfrom Two-Dimensional Sea Surface

Abstract

A hybrid model for describing a fully developedtwo-dimensional sea surface is presented, which incorporates the seaspectrum into a fractal model, and an improved two-scale model is applied tocalculate the scattering coefficient. In this model the slope distributionof the large-scale surface is obtained with a numerical method instead ofbeing assumed, and the projecting and ray tracing methods are applied toobtain the shadow function for arbitrary incident and scattering angles.Moreover the effect of curvature of the large-scale undulating surface onthe scattered wave is taken into account. Hence the precision of the results isgreatly increased at low-grazing angles. Finally the amplitude and fractalcharacteristics of the scattered wave are analysed, which are of greatsignificance for distinguishing and detecting targets on the sea.