【摘要】：隨著對雷達(dá)功能要求的不斷更新,新體制雷達(dá)不斷被研發(fā)出來。因此,對新體制雷達(dá)的測試迫切需要更強(qiáng)大的雷達(dá)信號模擬器。在雷達(dá)工作時(shí)會有許多與目標(biāo)無關(guān)的物體產(chǎn)生回波,這部分不需要的信號統(tǒng)稱為雜波。雜波會使得雷達(dá)無法精確探測目標(biāo),因此對雜波的模擬有助于檢測雷達(dá)在各類型雜波影響下的工作情況,同時(shí)也利于改善雷達(dá)性能。由于機(jī)載雷達(dá)處于運(yùn)動平臺,其接收到的雜波與地基雷達(dá)有很大區(qū)別,因此需要對其進(jìn)行專門研究。作為模擬器的重要組成部分,雜波模擬器的性能直接影響了對雷達(dá)測試的結(jié)果。對雷達(dá)回波的模擬主要包括目標(biāo)、噪聲和雜波三部分。相對目標(biāo)和噪聲而言,雜波的功率譜密度特性和幅度分布特性種類較多、形式較復(fù)雜,模擬的難度大。因此本文從常規(guī)情況下雷達(dá)雜波的幅度分布特性和功率譜密度特性分析入手,詳細(xì)研究了機(jī)載情況下雜波功率譜密度特性,在此基礎(chǔ)上設(shè)計(jì)了硬件模塊實(shí)現(xiàn)雜波模擬器功能。本文首先從雷達(dá)雜波模擬原理出發(fā),介紹了雜波幅度概率密度模型(瑞利分布模型、對數(shù)—正態(tài)分布模型、威布爾分布模型及K分布模型)和功率譜模型(高斯模型、指數(shù)模型和全極點(diǎn)模型),同時(shí)對比了兩種常用的雷達(dá)雜波模擬方法(ZMNL、SIRP)。其次針對機(jī)載雷達(dá)的雜波頻譜進(jìn)行了分析,根據(jù)機(jī)載雷達(dá)工作情況對機(jī)載雷達(dá)雜波功率譜進(jìn)行了數(shù)學(xué)建模,在此基礎(chǔ)上提出了便于工程實(shí)現(xiàn)的簡化模型,并對采用數(shù)學(xué)模型和簡化模型模擬的雜波功率譜進(jìn)行仿真分析和對比,同時(shí)對采用雜波功率譜簡化模型產(chǎn)生雜波數(shù)據(jù)的方法與步驟做了簡要介紹。然后利用基于雜波存儲的方案設(shè)計(jì)了機(jī)載雷達(dá)雜波模擬器的硬件原理框圖,并設(shè)計(jì)模擬器各功能模塊完成了雜波數(shù)據(jù)產(chǎn)生的硬件實(shí)現(xiàn)。最后對模塊和整機(jī)進(jìn)行測試,通過對結(jié)果的分析證明模擬器方案可行。本文采用的雜波功率譜簡化模型大大減少了實(shí)時(shí)計(jì)算雜波功率譜所花費(fèi)的時(shí)間,同時(shí)能夠準(zhǔn)確地反映出機(jī)載雷達(dá)雜波的各個(gè)特征量,在此基礎(chǔ)上設(shè)計(jì)的雜波信號硬件產(chǎn)生方案解決了傳統(tǒng)雷達(dá)雜波模擬器方案中實(shí)時(shí)計(jì)算方案耗時(shí)久和數(shù)據(jù)存儲方案占用資源大的矛盾,最終實(shí)現(xiàn)了高效而準(zhǔn)確地產(chǎn)生雜波數(shù)據(jù)。
[Abstract]:With the continuous updating of radar function requirements, the new radar system has been developed. Therefore, a more powerful radar signal simulator is urgently needed for the test of the new radar system. Many objects which are not related to the target will generate echo when the radar is working, and this part of the unwanted signal is called clutter. Clutter can not accurately detect the target, so the simulation of clutter is helpful to detect the radar performance under the influence of various types of clutter, and also to improve the radar performance. Because airborne radar is on the moving platform, the clutter it receives is very different from the ground radar, so it needs special research. As an important part of the simulator, the performance of the clutter simulator directly affects the radar test results. The simulation of radar echo mainly includes three parts: target, noise and clutter. Compared with the target and noise, there are many kinds of power spectral density and amplitude distribution characteristics of clutter, the form is more complex, and the simulation is difficult. In this paper, the amplitude distribution and power spectral density characteristics of radar clutter are analyzed, and the clutter power spectral density characteristics are studied in detail. On this basis, the hardware module is designed to realize the function of clutter simulator. Based on the principle of radar clutter simulation, this paper introduces the probability density model (Rayleigh distribution model, log-normal distribution model, Weibull distribution model and K-distribution model) and power spectrum model (Gao Si model). The exponential model and the full pole model) are compared with two common radar clutter simulation methods (ZMNL,SIRP). Secondly, the clutter spectrum of airborne radar is analyzed, and the power spectrum of airborne radar is modeled according to the working condition of airborne radar. Based on this, a simplified model is put forward, which is convenient for engineering implementation. The simulation analysis and comparison of clutter power spectrum simulated by mathematical model and simplified model are carried out, and the methods and steps of generating clutter data by using simplified model of clutter power spectrum are introduced briefly. Then, the hardware principle block diagram of airborne radar clutter simulator is designed based on the clutter storage scheme, and the hardware realization of clutter data generation is realized by every function module of the simulator. Finally, the module and the whole machine are tested, and the results show that the simulator scheme is feasible. The simplified model of clutter power spectrum adopted in this paper greatly reduces the time taken to calculate the clutter power spectrum in real time, and can accurately reflect the various characteristic quantities of airborne radar clutter. On this basis, the hardware generation scheme of clutter signal is designed to solve the contradiction between the long time consuming of real-time computing scheme and the large resource occupation of the data storage scheme in the traditional radar clutter simulator scheme. Finally, the clutter data can be generated efficiently and accurately.
【學(xué)位授予單位】：電子科技大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2014
【分類號】：TN959.73

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相關(guān)碩士學(xué)位論文 前1條

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本文編號：2316359