本文選題：機場道面異物　切入點：相干視頻信號模擬　出處：《電子科技大學》2014年碩士論文

【摘要】：機場道面異物FOD(Foreign Object Debris),即可能損傷飛機或系統(tǒng)的某種外來的物質(zhì)、碎屑或物體。常見的FOD有飛機和發(fā)動機連接件、道面的石頭和沙子、常用的機械工具、工作人員的物品等。FOD引起的空難不僅會損壞飛機和奪去寶貴的生命,同時也會影響機場的正常運轉(zhuǎn)。FOD雷達監(jiān)測系統(tǒng)主要用于實時監(jiān)測跑道上異物,及時、可靠地探測跑道異物。FOD通常為靜止目標,不能采用動目標檢測技術(shù),由于跑道背景同樣產(chǎn)生電磁散射,大面積的背景雜波成為目標檢測的主要干擾,因此對機場跑道場景回波合理地建模是研究異物檢測技術(shù)的基礎。本文針對這一問題,結(jié)合實際機場跑道周邊環(huán)境,分析該場景下雜波和目標的散射特性,給出適合該場景的回波模擬方法。本文的研究工作主要包括:(1)給出相干視頻信號模擬的基本原理,結(jié)合FOD實際工作場景,建立場景的幾何模型,研究分辨單元內(nèi)雜波和目標的散射特性,給出該場景雷達回波信號的產(chǎn)生方法。(2)研究粗糙地面后向散射系數(shù)的計算方法,給出單散射模型和多散射模型的原理,分析影響地面后向散射系數(shù)的因素,如地面粗糙度、介電常數(shù)、相關函數(shù)等因素。給出在地面接近光滑情況下,干地面、濕地面、被冰和雪覆蓋地面的后向散射系數(shù)的參考值。(3)FOD監(jiān)測系統(tǒng)采用高分辨率的毫米波雷達,且掠射角很小,這種場景下的雜波滿足非瑞利分布特性,分析對數(shù)正態(tài)分布、韋布爾分布和K分布的幅度分布特性,分析在一定誤差下三種分布的概率密度函數(shù)曲線逼近情況。研究產(chǎn)生雜波的兩種方法,即零記憶非線性變換法(ZMNL)和球不變隨機過程法(SIRP),結(jié)合上述方法研究產(chǎn)生這三種分布雜波的原理,給出相應的MATLAB仿真結(jié)果。(4)給出常見FOD目標的雷達截面積(RCS)經(jīng)驗公式,分析不同姿態(tài)下目標的RCS,及目標尺寸和發(fā)射頻率對RCS的影響。結(jié)合FOD場景目標和雜波的散射特性,給出雷達掃描區(qū)域內(nèi)回波信號的MATLAB仿真結(jié)果,將回波信號進行脈沖壓縮處理,分別對雜波和目標信息進行驗證。
[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.
【學位授予單位】：電子科技大學
【學位級別】：碩士
【學位授予年份】：2014
【分類號】：V351;TN957.51

【參考文獻】

相關期刊論文 前1條

1 孫立新;;跑道FOD檢測系統(tǒng)關鍵技術(shù)分析[J];四川理工學院學報(自然科學版);2010年04期

，

本文編號：1674666