Polarimetric entropy of the ocean surface with a two-scale scattering model

The relationships among an ocean wave spectrum, a fully polarimetric coherence matrix, and radar parameters are deduced with an electromagnetic wave theory. Furthermore, the relationship between the polarimetric entropy and ocean wave spectrumis established based on the definition of entropy and a twoscale scattering model of the ocean surface. It is the first time that the polarimetric entropy of the ocean surface is presented in theory. Meanwhile, the relationships among the fully polarimetric entropy and the parameters related to radar and ocean are discussed. The study is the basis of further monitoring targets on the ocean surface and deriving oceanic information with the entropy from the ocean surface. The contrast enhancement between human-made targets and the ocean surface with the entropy is presented with quad-pol airborne synthetic aperture radar (AIRSAR) data.