Diffraction techniques in rcs prediction of an aircraft model

Aircraft or ship is of interest as a target in radar wavelength of X-band in the optical RCS regime. In this region, analytical approximate techniques are used for RCS modeling. Physical Optics (PO) is a popular method on which many efficient computer codes are based. Alternative ray based methods are Geometrical Theory of Diffraction (GTD) and its extension Equivalent Currents (EC) which take diffraction into account. In this paper, RCS estimation results of GTD/EC are compared to PO for some geometry. It is concluded that although PO codes are very efficient, they fail at describing diffraction. Finally the RCS of an aircraft model is estimated using hybrid GTD-EC method at X-band. It is deduced that the implemented method is suitable in case of echo area estimation of electrically large bodies having no fine features.