Numerical analysis of multiple scattering from nonspherical objects

Numerical analysis of a multiple scattering is very important for radar and antenna applications. A reliable method for analyzing the 3D scattering problem is the Yasuura method. This method is applicable to 3D multiple scattering as well as to single scattering problems. In order to show the effectiveness of the Yasuura method, we apply it to 3D multiple scattering from nonspherical objects. We expand individual scattered fields from each of the objects by spherical vector wave functions written about the origins located inside each of the objects, and express a scattered field as a superposition of the individual fields (Mackowski, D.W., 1994). Furthermore, we re-expand the spherical vector wave functions by using a vector addition theorem in which the functions about one origin are expanded as the functions about another origin (Chew, W.C., 1992; Chew and Wang, Y.M., 1993). By determining the expansion (or unknown) coefficients so as to match the boundary condition on the surface of the objects in a least square sense, we can obtain numerical solutions. As numerical examples, we calculate radar cross sections of two objects as a function of the distance between them, and the near field patterns of three objects.