Radar cross section gradient calculation based on adjoint equation of method of moment

Abstract

A radar cross section gradient calculation method based on adjoint equation of method of moment (MoM) is proposed. The adjoint equation of method of moment as well as the variation of radar cross section is derived. Backscattering RCS of cylinder and missile model are firstly calculated and compared with measured data or FEKO MoM result to verify the reliability of the program adopted. Then, the cylinder and missile are parameterized and disturbed with domain element method. The gradient of design variables are computed with both adjoint method and finite-difference method. Numerical results of both methods are in good agreement proving that adjoint method has high reliability and precision. RCS gradient calculation based on adjoint equation has high efficiency, accuracy and can be applied in the calculation of complex geometry. It forms the basis of the gradient-based aerodynamic-stealth optimization platform.