Research on resonant scattering mechanism of curved target based on uniform geometrical theory of diffraction

Radar targets positioned within the resonance region can be identified by the natural poles; nonetheless, the physical connotation of the natural poles and the corresponding resonance mechanism remain ambiguous. To solve the diffraction problem, the resonant mechanism of a surface diffraction is explored by resorting to the uniform geometrical theory of diffraction (UTD), and a forward pole computational methodology is proffered for the identification of a target encompassing curved surface within the resonance region. Primarily, the closed path and geometric parameters of the creeping waves are obtained on the surface of the target by employing the projection recursive tracking algorithm. Subsequently, based on UTD, the expression of the curved surface diffraction field is proffered, and the resonance equation for predicting the poles is deduced. Ultimately, the poles of the ideal conductor sphere and spheroid are predicted and compared with the poles extracted from the frequency domain simulation. The comprehensive error is less than 5%, thereby validating the accuracy of the modeling approach.