Research On Electromagnetic Scattering Characteristics Of Chaff Cloud Based On Vector Transmission Theor

Chaff is one of the most popularly used passive jamming tool.In military field of electronic countermeasures,chaff plays an vital role in anti-ship and anti-missile mission.Therefore,the research of electromagnetic scattering characteristics of chaff clouds is of crucial importance.Based on the antenna theory and radiation transfer theory,the Monte Carlo approach is used to investigate the scattering features and diffusion properties of chaff clouds.Upon the basis of the actual marine environment of chaff interference,the low-altitude multipath impact and the jamming effects in different interferences are studied in this work.Firstly,based on the antenna radiation theory,in a global coordinate system,the bistatic fully polarized scattering matrix of half-wavelength chaff is formulated.With evenly distributed placement angle,the average fully polarized radar cross section is derived hence.When ignoring the coupling effect between chaffs,the scattering source approximation method is used to analyze the statistical distribution model of the Radar Cross Section(RCS)of the chaff clouds.Secondly,based on radiation transfer theory,the Monte Carlo approach is applied to simulate the absorption,scattering and propagation process for the chaff cloud.Considering the multiple scattering between the chaffs,the scattering properties and masking effect of dipole clouds are analyzed.By comparing with the results obtained through a commercial software package,i.e.the FEKO,the proposed method in this work is reasonably verified.According to the low Reynolds number theory,the diffusion equation of the chaff is deduced.Then,the motion model of the dynamic dipole clouds is found.Thus,the physical movement process and scattering features of dipole clouds can be analyzed.Finally,based on the four-path method and ray-tracing theory,a detailed simulation model is established to study the dynamic electromagnetic coupling mechanism between the chaff cloud and sea.At the same time,the effect of sea clutter background on chaff cloud’s electromagnetic scattering is also studied.When the chaff cloud is closed to the sea,the electromagnetic scattering of chaff cloud can be enhanced by the sea.In addition,the scattering enhancement effect is related to the incident direction and the distance between the chaff cloud and the sea surface.According to a simulated combat scenario,the jamming mechanisms and application scenario of centroid jamming,diluting jamming and shadowing jamming are analyzed.The effects of chaff clouds in different jamming means are exhibited.