The physics and modelling of discrete spikes in radar sea clutter

Abstract

This paper first examines the physical source of sea clutter spikes from considerations of oceanographic principles and electromagnetic scattering; it is shown how electromagnetic scattering theory can be used to predict the characteristics of discrete spikes in backscatter from the sea. The spikes can also be modelled statistically as extensions to the standard K-distribution model for sea clutter, as proposed by K.D. Ward et al. (1990). In this paper, the work in K.D. Ward et al. (1990) is extended to include the addition of thermal noise and it is also shown how the parameters of this model can be matched to real data. Results are presented for recorded airborne radar data, showing how the model can accurately match the characteristics of real clutter-plus-spikes-plus-noise, including the effects of pulse-to-pulse integration with frequency agility.