HIGH-RESOLUTION POLARIMETRIC RADAR SCATTERING MEASUREMENTS OF LOW GRAZING ANGLE SEA CLUTTER

This paper presents fully polarimetric radar scattering measurements o f low grazing angle sea clutter. The measurements were obtained at a t hree degree grazing angle using a high range resolution (1.5 m) X-Band polarimetric radar operated from a shore site overlooking the Chesape ake Bay. The radar employs pulse-to-pulse switching between orthogonal transmitted polarizations and simultaneously measures two orthogonall y polarized components of the backscattered wave to obtain full polari metric information about the scattering process. The complete Stokes m atrix, computed by averaging successive realizations of the polarizati on scattering matrix. Is used to obtain polarization signatures and to determine the polarization dependence of the clutter. Sea spike echoe s are shown to be weakly polarized and to exhibit polarization signatu res indicative of multiple independent scattering mechanisms. Clutter echoes in the absence of sea spikes are shown to be highly polarized a nd to exhibit polarization signatures indicative of a single dominant scattering mechanism.