Electromagnetic diffraction computation for a high accuracy direction finder on board a helicopter

A comparison between some different theoretical methods for the simulation of electromagnetic scattering phenomena is presented. These methods are used to adjust a synthetic antenna direction finder for helicopter. This system operates with the rotating wing diffraction by marking one blade of the principal rotor. The signal processing used requires an accurate modelisation of the electromagnetic interactions between the incident signal from the radio-beacon and helicopter various elements (marker, rotor blades, airframe). Some of calculation methods are compared and allows to make choices on the more appropriate one to optimise the system.