Low computational cost method for scattering of large cavities based on ACA compression of Iterative Physical Optics

This paper is about Radar Cross Section (RCS) calculation of large cavities. For such targets, Iterative Physical Optics (IPO) is a method known to provide a good trade-off between complexity and accuracy. In this article, a numerical compression is applied to interaction matrices of IPO between coupled surfaces. The compression is made by using the algebraic Adaptive Cross Approximation (ACA) technique, which is known to provide a good compression and acceleration when used with dense matrices involved in rigorous numerical methods. It is also improved by a recompression (RACA). Results show that this technique highly compresses the IPO matrices, without damaging the RCS prediction by IPO.