High resolution polarimetric radar scattering measurements of low grazing angle sea clutter

This paper presents fully polarimetric radar scattering measurements of low grazing angle sea clutter. The measurements were obtained at a three degree grazing angle using a high range resolution (1.5 m) X-band polarimeter operated from a shore site overlooking the Chesapeake Bay. Analysis of these measurements indicates that “sea spike” radar echoes are caused by a combination of two or more independent scattering mechanisms, such as a population of non-Bragg scatterers at breaking wave crests, superimposed on a background of distributed Bragg resonant waves. The experimental data are compared with theoretical polarimetric scattering models based on Bragg scattering as well as Bragg scattering augmented with scattering from wedges and plumes. Polarization signatures for the composite Bragg+plume model are shown to more closely predict the experimental data than the Bragg model alone or the composite Bragg+wedge scattering model