EM modeling of aircraft at low frequencies

An efficient computational technique for obtaining scattering cross sections of electrically small aircraft is presented. The technique is based on the wire-grid reaction method. The aircraft shape is approximated by a grid of thin wires, leading to a mathematical representation of the aircraft in the form of an impedance matrix. The inverted matrix yields the scattering data. A variety of wire-grid models were tested. The results show that with proper choice of radius of the wire segments, good agreement with experimental data can be obtained for polarizations parallel to the fuselage axis. For polarizations perpendicular to the fuselage axis, only fair agreement was observed. This computational technique is used to simulate realistic scattering data, which serves as input to information processors for target identification.