Study On Radar Jamming Characteristics Of Chaff In Rarefied Atmosphere

Chaff cloud, as one of the most historical passive jamming methods, has been used in a new battlefield environment of the mid-course trajectory. It is necessary to know the characteristics of chaff cloud in rarefied atmosphere, in order to give full play to its jamming effects. Therefore, this paper has analyzed the motional diffusion, electromagnetic scattering and wave propagation properties of chaff cloud. Then it has mainly discussed the high resolution range profile(HRRP) properties of chaff jamming and the characteristics of active repeating jamming combing scattering effects on chaffs. Based on relative results, the paper evaluates the jamming effects by simulations and puts forward suggestions on jamming technologies. The work can be summarized into three aspects:The first aspect is about the basic characteristics of chaff cloud. Considering the ballistic trajectory in specific atmosphere environment, this paper firstly analyzes the initial orientation distribution and motional diffusion characteristics of chaff clouds which have been released. The radar scattering characteristics of chaff cloud are achieved from single chaff's referring to the theory of coherent combination. According to the forward and backward scattering theory, the effective propagation constant of chaff clouds is deduced at typical incident plane waves. At last, the wave propagation and attenuation properties in chaff clouds are shown in typical parameters.The second aspect is about the HRRP characteristics of chaff cloud. Referring to the HRRP imaging theory, the paper simulates the HRRP characteristics of chaffs with random distribution under the circumstances of different releasing methods and different orientations in rarefied atmosphere.The final aspect is about the characteristics of active repeating jamming combing scattering effects on chaffs. The paper has verified the feasibility of this jamming technology from the point of power. After receiving the radar LFM signal, the jammer repeats it directly with a proper interval or transmits it after some kind of modulation to reach chaffs finally. Then the ground-based defense radar receives scattering echoes of chaffs. Referring to the model of this jamming method, the paper has achieved the imaging and jamming characteristics of chaff cloud.