本文選題：氣象雷達(dá)　切入點(diǎn)：DPRF速度擴(kuò)展　出處：《西安電子科技大學(xué)》2014年碩士論文　論文類型：學(xué)位論文

【摘要】：氣象雷達(dá)是大氣監(jiān)測的一個(gè)主要手段,但由于氣象雷達(dá)的工作波長較短,在一定的發(fā)射重復(fù)頻率下,可能會同時(shí)存在速度模糊和距離模糊問題。而模糊問題的存在會引起譜矩參數(shù)估計(jì)不準(zhǔn)確,還會造成雷達(dá)難以觀察和預(yù)測一些特殊的氣象現(xiàn)象。針對這一問題本文主要討論了氣象雷達(dá)信號處理算法中解模糊的實(shí)現(xiàn)方法。其主要內(nèi)容有:1.對氣象雷達(dá)的回波特性進(jìn)行討論。分析了時(shí)域特性和頻域特性,仿真構(gòu)建了一種常見的氣象回波高斯模型,給出了工程上常用的兩種譜矩估計(jì)算法,時(shí)域PPP法和頻域FFT,同時(shí)分析了這兩種譜矩估計(jì)的性能,并給出實(shí)測回波圖。2.對解速度模糊的實(shí)現(xiàn)方法進(jìn)行了分析與討論。說明了判別速度模糊的方法,討論了幾種解速度模糊的方法,包括軟件法、DPRF速度擴(kuò)展法以及三PRF法等,其中,主要討論了工程上常用的DPRF速度擴(kuò)展法,針對在DPRF擴(kuò)展速度中存在部分速度區(qū)域的再次模糊的問題,結(jié)合仿真分析,對原始的速度擴(kuò)展公式作了一些相應(yīng)的改進(jìn),使得修正后的速度估計(jì)公式真正解決了某一范圍內(nèi)存在的速度模糊的問題。3.對氣象信號處理中的解距離模糊方法進(jìn)行了一系列的討論與仿真分析。簡單說明了隨機(jī)相位編碼法解距離模糊的原理以及其在工程實(shí)現(xiàn)中存在的問題,針對問題給出了一種改進(jìn)后的SZ-2相位編碼,主要討論了SZ-2相位編碼的相關(guān)技術(shù)問題,包括SZ(8/64)相位編碼、FIR帶阻濾波器的設(shè)計(jì)以及在解距離模糊時(shí)對于地物雜波抑制的處理技術(shù)等問題,同時(shí)進(jìn)行了仿真分析,而且通過仿真將高斯自適應(yīng)頻域?yàn)V波與時(shí)域上四階IIR高通橢圓濾波器抑制的性能進(jìn)行了對比,得出高斯自適應(yīng)頻域?yàn)V波在地物雜波抑制上具有更好的效果,以及簡單闡述了SZ-2相位編碼的性能。本文是在實(shí)現(xiàn)氣象雷達(dá)常規(guī)處理的基礎(chǔ)上,分別對解速度模糊和解距離模糊采用DPRF速度擴(kuò)展法和SZ-2相位編碼技術(shù),并編寫了相應(yīng)的DSP程序。實(shí)驗(yàn)結(jié)果表明:這兩種方法都達(dá)到較好的效果。
[Abstract]:Meteorological radar is one of the main means of atmospheric monitoring. However, due to the short working wavelength of meteorological radar, at a certain transmitting repetition rate, There may be both velocity ambiguity and distance ambiguity, and the existence of fuzzy problems may lead to inaccurate estimation of spectral moment parameters. It is also difficult for radar to observe and predict some special meteorological phenomena. This paper mainly discusses the method of resolving ambiguity in the signal processing algorithm of meteorological radar. The main contents of this paper are: 1. The characteristics of time domain and frequency domain are analyzed. In this paper, a common Gaussian model of meteorological echo is constructed, and two common spectral moment estimation algorithms, time-domain PPP method and frequency-domain PPP method, are given. The performance of these two spectral moments estimation is also analyzed. The realization method of velocity ambiguity solution is analyzed and discussed. The methods to distinguish velocity ambiguity are explained, and several methods to resolve velocity ambiguity are discussed, including software method, DPRF velocity expansion method and three PRF method, etc. This paper mainly discusses the DPRF speed expansion method commonly used in engineering. Aiming at the problem of re-blurring part of the velocity region in the DPRF expansion speed, combined with the simulation analysis, some corresponding improvements are made to the original velocity expansion formula. The modified velocity estimation formula can really solve the problem of velocity ambiguity in a certain range. 3. A series of discussion and simulation analysis on the method of resolving distance ambiguity in meteorological signal processing are carried out. The principle of resolving distance ambiguity by computer phase coding method and its problems in engineering implementation. In this paper, an improved SZ-2 phase coding is presented, and the related technical problems of SZ-2 phase coding are discussed. Including the design of the phase coded Fir band-stop filter and the processing technology of ground clutter suppression when the distance is blurred, the simulation analysis is also carried out. Moreover, the performance of Gao Si adaptive frequency domain filter and fourth order IIR high pass elliptic filter in time domain is compared by simulation. It is concluded that Gao Si adaptive frequency domain filter has better effect on ground object clutter suppression. Based on the conventional processing of meteorological radar, the DPRF velocity expansion method and SZ-2 phase coding technique are used to solve the velocity ambiguity and range ambiguity, respectively. The corresponding DSP program is written and the experimental results show that the two methods achieve good results.
【學(xué)位授予單位】：西安電子科技大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2014
【分類號】：TN959.4

【共引文獻(xiàn)】

相關(guān)期刊論文 前1條

1 劉生鋒;嚴(yán)勇;陸建兵;;隨機(jī)相位編碼在多普勒天氣雷達(dá)中的應(yīng)用[J];現(xiàn)代雷達(dá);2014年06期

相關(guān)碩士學(xué)位論文 前1條

1 李敏杰;脈沖多普勒氣象雷達(dá)解模糊問題研究[D];合肥工業(yè)大學(xué);2013年

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本文編號：1582709