Comparison of the domain of validity of several approximate surface scatter theories

A new generalized Harvey-Shack (GHS) surface scatter theory is numerically compared to the classical small perturbation method (SPM), the Kirchhoff approximation method (KM) and the rigorous method of moment (MoM) for one-dimensional ideally conducting surfaces whose surface power spectral density function is Gaussian or abc-function. In spite of its simple analytic form, our numerical comparison shows that the new GHS theory is valid (with reasonable accuracy) over a broader range of surface parameter space than either of the two classical surface scatter theories.