Investigation of phase difference statistics of numerically simulated high-resolution HH- and VV-polarized low grazing angle sea backscatter

This study uses direct numerical simulations of X-band low grazing sea backscatter to investigate phase difference statistics between the co-polarized (horizontal transmit-receive and vertical transmit-receive) channels. The range resolution is 0.4 m and the grazing angles are as low as 0.5 degrees. The simulations are limited to the two-dimensional space but have immediate relevance to commonly occurring observation geometries. Phase probability density functions are calculated using different methods (such as amplitude thresholding or multilook averaging) and are shown to differ substantially from analytical predictions based on the commonly used Gaussian-statistics assumptions. Adequate knowledge of such inter-channel phase probability distributions is important for ocean-oriented applications of radar polarimetry.