Combined Calculation Method for the Scattering Characteristics of Complex Shaped Objects and Its Application to Model Helicopter Rotor Modulation Spectra

A combined electrodynamic method for calculating the scattering characteristics of radar objects with complex shape is proposed. Objects can contain structural elements of different electric sizes. The proposed algorithm is based on the joint use of the high-frequency method for calculation of scattering characteristics of electrically large structural elements and the method of integral equations for parts commensurate to the wavelength, including electrically thin ones. The combined method advantages are demonstrated with the calculation of helicopter rotor modulation spectra in the VHF band.