摘要
研究了微动目标的多普勒回波模拟及特征参数提取技术.提出了一种基于物理光学法和等效电磁流法的扩展性微动目标回波模拟方法.将在目标坐标系下计算得到的后向散射场通过坐标转换,成为雷达坐标系下的目标回波,通过与解析信号模型对比验证方法的正确性.分析了圆锥与带翼弹头的进动特性,为获得较好的时频聚集性同时避免交叉项采用S-method方法对获取的回波信号进行时频分析,分析了不同雷达波入射角度,不同运动状态及不同几何外形的时频分布特点.对时频分布图进行逆Radon变换,将正弦曲线映射到参数空间,从而获取目标的微动参数.该研究结合电磁散射与信号处理技术,通过对典型弹道目标的仿真,获得一些不同于传统微动模型的结果,结合电磁散射理论,对这些现象进行了解释分析.该研究成果在弹道目标的探测识别领域具有重要的理论与应用价值.
The micro-motion Doppler echo simulation and characteristic parameter extraction of the extended micro-motion target are carried out. For the extended micro-motion target, the echo from the target cannot be regarded as several points＇ echo. Based on the connections between the scattering field and Doppler echo, an echo simulation method for micro-motion target（based on physical optics） and a method of equivalent current are proposed. At the moment,the micro-motion target can be taken as a static target, so the back scattering field series can be calculated by physical optics and the method of equivalent current. The back scattering field series calculated in the target coordinate system is transformed into the echo of radar coordinate system by the conversion of coordinates, and the Doppler echo is obtained.By comparing with the analytic signal model, the method is validated. The precession characteristics of a cone and warhead with fins are analyzed. Echoes come from every part of the extended micro-motion target and contain the motion characteristics of that part. So the traditional time-frequency analytical methods are not appropriate. In order to achieve better time frequency concentration and avoid the cross terms, the S-method is used to get the time-frequency distributions. The time-frequency characteristics at different radar waves＇ incidence angles, target different motion states and different geometries are analyzed. From the time-frequency distribution map, the micro-motion of the cone behaves as the micro-motion of two strong scattering points at the bottom of the cone. Because of the shielding effect, the timefrequency curves are not integrated when the radar waves are incident from the cone＇s bottom. The sinusoidal curve can be mapped to a point in the parameter space based on the inverse radon transform, and the target micro-motion parameters can be obtained. Results of inverse radon transform also show that the precession of the cone behaves as the precession of the two strong scattering
出处
《物理学报》
SCIE
EI
CAS
CSCD
北大核心
2015年第21期160-168,共9页
Acta Physica Sinica
基金
国家自然科学基金(批准号:61372033)资助的课题~~
