【摘要】：星載雷達(dá)(SBR)在現(xiàn)代生產(chǎn)生活中扮演的角色越來越重要,它克服了地面雷達(dá)、艦載雷達(dá)和機(jī)載雷達(dá)的諸多缺點,有著全天候、探測空域非常大、預(yù)警時間長、不受領(lǐng)空限制等優(yōu)點,在民用和軍事領(lǐng)域發(fā)揮著不可替代的作用。星載雷達(dá)也有種種難以解決的問題,其中之一便是其雜波的處理比地面、機(jī)載和艦載雷達(dá)的雜波處理要復(fù)雜。星載雷達(dá)發(fā)射的電磁波會覆蓋地面或海洋一個巨大的區(qū)域,從而產(chǎn)生大量的雜波。同時,雷達(dá)平臺和地球無時無刻不處于快速移動當(dāng)中,所以還會產(chǎn)生不可忽視的多普勒效應(yīng)。波束腳印越大,影響雷達(dá)性能的干擾源就越多,這使得照射區(qū)域產(chǎn)生的雜波信號會嚴(yán)重的污染目標(biāo)信號。要從被污染過的回波信號中準(zhǔn)確的檢測出目標(biāo),就必須先對雜波做有效的處理。因此關(guān)于星載雷達(dá)雜波的研究就變得非常有意義。在不用實測的情況下、僅借助計算機(jī)平臺就得到雜波信號,被稱為雜波的模擬。它與地面/機(jī)載等雷達(dá)的雜波的模擬有相近或相同之處,但由于星載雷達(dá)自身的特點,所以也大量不同的地方。本文所做的研究工作主要是星載雷達(dá)雜波的模擬和仿真,采取方法為:利用雷達(dá)回波與發(fā)射波形的一般關(guān)系,根據(jù)波束所覆蓋的實際區(qū)域建立雜波模型。仿真中用到的特定地區(qū)的各種參數(shù)、地球轉(zhuǎn)動的數(shù)據(jù)、地物特性、高程數(shù)據(jù)由地理信息系統(tǒng)(GIS)提供;雜波的后向散射系數(shù)、多普勒頻移、天線增益等數(shù)據(jù)來自于星載雷達(dá)本身的工作參數(shù)。本文所做的主要工作如下:1.分析星載雷達(dá)雜波模擬的意義和前人所做的工作,介紹常用的模擬方法以及雜波的概率分布,討論基于地理信息系統(tǒng)建立的雜波模型思路和優(yōu)勢;2.通過計算和作圖,推導(dǎo)星載雷達(dá)雜波的研究中所涉及的關(guān)鍵參數(shù)。其中包括衛(wèi)星平臺的參數(shù)、波束的參數(shù)、照射區(qū)域的參數(shù)等;3.建立星載雷達(dá)雜波模型。運用矩形網(wǎng)格映像法,將雷達(dá)波束照射的實際區(qū)域進(jìn)行分塊,利用地理信息系統(tǒng)提供的參數(shù),計算出各雜波小塊的各個參數(shù);4.對實際的波束照射區(qū)域進(jìn)行雜波仿真、生成最終雜波。利用雷達(dá)方程,推導(dǎo)出雜波小塊回波信號與發(fā)射信號的關(guān)系,并利用實際地面的各個參數(shù)模擬出雜波;5.對雜波的性能進(jìn)行分析、總結(jié),探討存在的問題。
[Abstract]:Space-borne radar (SBR) plays a more and more important role in modern production and life. It overcomes many shortcomings of ground radar, shipborne radar and airborne radar. It has the advantages of all-weather, very large airspace detection, long early warning time, no airspace restriction and so on. It plays an irreplaceable role in civil and military fields. There are also many difficult problems to be solved in space-borne radar, one of which is that the clutter processing is more complex than that of ground, airborne and shipborne radar. The electromagnetic waves emitted by space-borne radar will cover a large area of the ground or ocean, resulting in a large number of clutters. At the same time, the radar platform and the earth are moving rapidly all the time, so they will also produce Doppler effect that can not be ignored. The larger the beam footprint, the more interference sources affect the radar performance, which makes the clutter signal generated in the irradiated area seriously pollute the target signal. In order to detect the target accurately from the contaminated echo signal, it is necessary to deal with the clutter effectively. Therefore, the research on the clutter of space-borne radar becomes very meaningful. In the absence of actual measurement, the clutter signal is obtained only with the help of computer platform, which is called the simulation of clutter. It is similar to or similar to the simulation of ground / airborne radar, but because of the characteristics of space-borne radar, there are a lot of different places. The research work done in this paper is mainly the simulation and simulation of space-borne radar clutter. the method is as follows: using the general relationship between radar echo and transmit waveform, the clutter model is established according to the actual area covered by beam. The parameters used in the simulation, the data of earth rotation, the characteristics of ground objects and the elevation data are provided by Geographic Information system (GIS). The data of backscattering coefficient, Doppler frequency shift and antenna gain of clutter come from the working parameters of space-borne radar itself. The main work done in this paper is as follows: 1. This paper analyzes the significance of space-borne radar clutter simulation and the work done by its predecessor, introduces the commonly used simulation methods and the probability distribution of clutter, and discusses the ideas and advantages of the clutter model based on geographic information system (GIS). 2. Through calculation and mapping, the key parameters involved in the research of space-borne radar clutter are derived. These include the parameters of the satellite platform, the parameters of the beam, the parameters of the irradiation area, etc. The clutter model of space-borne radar is established. By using the rectangular grid image method, the actual area irradiated by radar beam is divided into blocks, and the parameters of each clutter block are calculated by using the parameters provided by geographic information system (GIS). 4. The actual beam irradiation area is simulated to generate the final clutter. The relationship between the echo signal and the transmitted signal is derived by using the radar equation, and the clutters are simulated by using the parameters of the actual ground. The performance of clutter is analyzed, summarized and the existing problems are discussed.
【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】：TN957.52

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相關(guān)期刊論文 前1條

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本文編號：2502441