Hd. Ngo et Cl. Rino, APPLICATION OF BEAM SIMULATION TO SCATTERING AT LOW GRAZING ANGLES .1. METHODOLOGY AND VALIDATION, Radio science, 29(6), 1994, pp. 1365-1379
Numerical simulations of rough surface scattering at near-grazing inci
dence require very large surfaces (greater than or similar to 500 lamb
da). Conventional methods of exact solutions require the inversion of
a very large matrix, which can exceed the memory and speed capabilitie
s of even modern supercomputers. The beam simulation method proposed b
y Saillard and Maystre circumvents this problem by decomposing the lar
ge incident beam into narrower subbeams and then synthesizing the larg
e beam by coherent superposition. The radius of these narrower subbeam
s is determined by the local interaction distance on the surface, whic
h is found to increase with incidence angle, ultimately forcing a sing
le beam in the limit of strict grazing incidence. This paper demonstra
tes that this technique gives essentially the same results as can be o
btained by the method of moments and can handle surfaces as large as 1
000 lambda for grazing incidence angle as low as 10 degrees.