Research On Electromagnetic Properties Of Chaff Cloud Based On Double-layer Spherical Equivalent Source-region Decomposition Algorithm

Chaff is a commonly used jaming technicque in military war,which plays an important role in anti-ship and anti missile application.Therefore,it is of great significance to study the electromagnetic scattering and Doppler characteristics of chaff cloud for radar jamming and anti-jamming technology.Based on this,the main research contents of this article are as follows:Firstly,the electromagnetic model of chaff cloud is established using the double-layer spherical equivalent domain decomposition algorithm(D-EPA-Bo R)to take account of the mutual coupling effect.In order to solve the scattering characteristics of a large number of chaff clouds more efficiently,only the near-field coupling less than two wavelengths are considered.And MPI parallel and Open MP parallel technology are introduced to further improve the computation efficiency.Secondly,the double spherical equivalent source domain decomposition algorithm computing platform is used to establish the translation and micro motion models of chaff cloud.When only considering the near-field coupling in two wavelengths,the translational Doppler characteristics and the micro-motion Doppler characteristics are studied based on the dynamic echo data of the cloud.The effects of incident frequencies and velocity variances on the translational Doppler broadening,the influence of the chaff clound density on translational Doppler amplitude are studied.And the effects of the length and the angular velocity of the chaff on the micro-Doppler characteristics are also studied.Finally,the dynamic echo data of the chaff cloud dropped from the aircraft or ship is solved by using the dipole far-field superposition theorem without considering the mutual coupling.And the change of attitude angle of the chaffs is also ignored during the movement.Then the dynamic echo data of the aircraft or ship/sea surface are calculated using the physical optics method(PO),in which the change of the attitude angle of the aircraft or ship are taken into account.Thus the interference characteristics of the airborne chaff cloud and the ship borne chaff cloud are obtained.