机场跑道场景雷达回波建模与仿真

发布时间：2018-03-28 04:07

本文选题：机场道面异物　切入点：相干视频信号模拟　出处：《电子科技大学》2014年硕士论文

【摘要】：机场道面异物FOD(Foreign Object Debris),即可能损伤飞机或系统的某种外来的物质、碎屑或物体。常见的FOD有飞机和发动机连接件、道面的石头和沙子、常用的机械工具、工作人员的物品等。FOD引起的空难不仅会损坏飞机和夺去宝贵的生命,同时也会影响机场的正常运转。FOD雷达监测系统主要用于实时监测跑道上异物,及时、可靠地探测跑道异物。FOD通常为静止目标,不能采用动目标检测技术,由于跑道背景同样产生电磁散射,大面积的背景杂波成为目标检测的主要干扰,因此对机场跑道场景回波合理地建模是研究异物检测技术的基础。本文针对这一问题,结合实际机场跑道周边环境,分析该场景下杂波和目标的散射特性,给出适合该场景的回波模拟方法。本文的研究工作主要包括:(1)给出相干视频信号模拟的基本原理,结合FOD实际工作场景,建立场景的几何模型,研究分辨单元内杂波和目标的散射特性,给出该场景雷达回波信号的产生方法。(2)研究粗糙地面后向散射系数的计算方法,给出单散射模型和多散射模型的原理,分析影响地面后向散射系数的因素,如地面粗糙度、介电常数、相关函数等因素。给出在地面接近光滑情况下,干地面、湿地面、被冰和雪覆盖地面的后向散射系数的参考值。(3)FOD监测系统采用高分辨率的毫米波雷达,且掠射角很小,这种场景下的杂波满足非瑞利分布特性,分析对数正态分布、韦布尔分布和K分布的幅度分布特性,分析在一定误差下三种分布的概率密度函数曲线逼近情况。研究产生杂波的两种方法,即零记忆非线性变换法(ZMNL)和球不变随机过程法(SIRP),结合上述方法研究产生这三种分布杂波的原理,给出相应的MATLAB仿真结果。(4)给出常见FOD目标的雷达截面积(RCS)经验公式,分析不同姿态下目标的RCS,及目标尺寸和发射频率对RCS的影响。结合FOD场景目标和杂波的散射特性,给出雷达扫描区域内回波信号的MATLAB仿真结果,将回波信号进行脉冲压缩处理,分别对杂波和目标信息进行验证。
[Abstract]:The foreign body on the airport surface, FOD(Foreign Object Debris, is a foreign substance, debris, or object that may damage an aircraft or system. The common FOD has aircraft and engine connections, pavement stones and sand, and commonly used mechanical tools. Staff items, etc. The air disaster caused by FOD will not only damage the aircraft and take away precious lives, but also affect the normal operation of the airport. The FOD radar monitoring system is mainly used to monitor foreign objects on the runway in real time and in time. The reliable detection of runway foreign bodies. Fod is usually a stationary target, so moving target detection technology can not be used. Because the background of runway also produces electromagnetic scattering, large area background clutter becomes the main interference of target detection. Therefore, the reasonable modeling of echo in airport runway scene is the basis of studying foreign body detection technology. In this paper, considering the surrounding environment of actual airport runway, the scattering characteristics of clutter and target in this scene are analyzed. The research work of this paper mainly includes: 1) giving the basic principle of coherent video signal simulation, combining with the actual working scene of FOD, establishing the geometric model of the scene. The scattering characteristics of clutter and target in the resolution unit are studied. The generating method of radar echo signal in this scene is given. The calculation method of backscattering coefficient of rough ground is given. The principle of single scattering model and multiple scattering model are given. The factors influencing the backscattering coefficient of the ground, such as roughness, dielectric constant, correlation function, etc., are analyzed. The dry and wet ground are given under the condition that the ground is close to smooth. The backscattering coefficient reference value of the backscattering coefficient covered by ice and snow. The FOD monitoring system uses a high-resolution millimeter-wave radar with a small grazing angle. The clutter in this scenario satisfies the non-Rayleigh distribution characteristics and analyzes the logarithmic normal distribution. The amplitude distribution characteristics of Weibull distribution and K distribution are analyzed. The approximation of probability density function curves of three distributions under certain errors is analyzed. Two methods for generating clutter are studied. The zero memory nonlinear transformation method (ZMNL) and the spherical invariant random process method (SIRPU) are used to study the principle of generating these three distributed clutter, and the corresponding MATLAB simulation results are given. The empirical formula of radar cross section area (RCS) of common FOD targets is given. The effects of target size and transmitting frequency on RCS are analyzed. Combined with the scattering characteristics of target and clutter in FOD scene, the MATLAB simulation results of echo signal in radar scanning region are given, and the echo signal is processed by pulse compression. The clutter and target information are verified respectively.
【学位授予单位】：电子科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：V351;TN957.51

【参考文献】