Gd. Dockery et Jr. Kuttler, AN IMPROVED IMPEDANCE-BOUNDARY ALGORITHM FOR FOURIER SPLIT-STEP SOLUTIONS OF THE PARABOLIC WAVE-EQUATION, IEEE transactions on antennas and propagation, 44(12), 1996, pp. 1592-1599
A new implementation of the previously published mixed Fourier transfo
rm (MFT) method for including impedance boundaries in split-step parab
olic equation solutions is described and demonstrated. The new algorit
hm is formulated entirely in the discrete domain which results in exte
nded applicability and increased computation speed. A brief review of
the original MFT solution is followed by a detailed description of the
discrete formulation. The performance of the new algorithm is then de
monstrated with a few examples which rely heavily on the accuracy of t
he impedance boundary. These examples include 10 MHz surface wave prop
agation over smooth and rough sea surfaces and 18 GHz calculations uti
lizing an effective rough surface impedance.