本文選題：DOA估計 + 長線陣��； 參考：《國防科學技術(shù)大學》2014年碩士論文

【摘要】：水下目標輻射噪聲的不斷降低給目標探測帶來巨大挑戰(zhàn),迫使水下探測系統(tǒng)不斷向大孔徑長線陣的方向發(fā)展。但是在實際海洋環(huán)境中,水聲信道中多號簡正波的干涉效應以及非高斯環(huán)境背景噪聲都會使得常規(guī)線列陣測向算法應用于長線陣時性能下降,甚至無法進行目標測向。因此開展長線陣在淺海波導和復雜環(huán)境噪聲背景下的測向算法研究是其走向應用以及發(fā)展高性能水下目標探測系統(tǒng)的重要基礎。論文基于簡正波理論對淺海波導中復雜環(huán)境背景噪聲下長線陣測向算法展開深入研究,主要工作和創(chuàng)新點如下:1、針對簡正波聲場下的長線陣測向模型,推導并分析了淺海波導中聲場水平縱向相關(guān)性隨信號頻率、聲源與陣列距離等參數(shù)變化的規(guī)律。在基于平面波模型的各種定向算法研究的基礎上,從理論和仿真分析了淺海波導中長線陣定向出現(xiàn)的譜峰分離或譜峰分裂現(xiàn)象的原因,其研究結(jié)果表明隨著聲波的傳播聲場空間相干性會出現(xiàn)周期性的起伏,淺海多號簡正波的疊加會造成基于平面波模型的測向算法出現(xiàn)譜峰偏移和分裂。2、系統(tǒng)研究了基于簡正波模型的子空間相交算法及其改進算法,分別在不同信噪比、不同快拍數(shù)、不同信號頻率等條件以及水平波矢、簡正波號數(shù)估計失配、信源數(shù)目估計失配等參數(shù)失配條件下對各算法的目標定向性能進行了仿真分析,探討了這些算法在不同淺海波導條件下長線陣測向問題的優(yōu)劣和適用性。3、針對復雜海洋環(huán)境背景噪聲的空間非高斯特性,利用高階累積量可抑制高斯噪聲的原理,提出了將基于簡正波模型的子空間相交算法與高階累積量相結(jié)合的算法。仿真結(jié)果結(jié)果表明:在高斯白噪聲、高斯分布的空間色噪聲、瑞利白噪聲以及瑞利分布的空間色噪聲等環(huán)境噪聲情況下,該算法能夠?qū)崿F(xiàn)淺海波導多模式傳播條件下長線陣的準確定向。
[Abstract]:The continuous reduction of underwater target radiated noise brings great challenge to target detection, and forces the underwater detection system to develop to the direction of large aperture linear array. However, in the actual marine environment, the interference effect of multi-signal normal wave in underwater acoustic channel and the background noise in non-Gao Si environment will make the performance of conventional linear array direction finding algorithm decline when it is applied to long linear array, and even the target direction finding can not be carried out. Therefore, the research of direction finding algorithm of long linear array in shallow water waveguide and complex ambient noise background is an important foundation for its application and the development of high performance underwater target detection system. Based on the theory of normal wave, this paper deeply studies the direction finding algorithm of long linear array in shallow water waveguide with complex background noise. The main work and innovation are as follows: 1, aiming at the direction finding model of long line array under normal wave sound field. The vertical correlation of sound field in shallow water waveguide is deduced and analyzed with the variation of signal frequency, distance between sound source and array, and so on. Based on the research of various directional algorithms based on plane wave model, the causes of spectral peak separation or peak splitting in shallow water waveguide with long linear array orientation are analyzed theoretically and numerically. The results show that the spatial coherence of sound field will fluctuate periodically with the sound wave propagation. The superposition of multiple normal waves in shallow water will result in spectral peak migration and splitting of direction-finding algorithm based on plane wave model. The subspace intersection algorithm based on normal wave model and its improved algorithm are studied systematically, respectively at different signal-to-noise ratio (SNR) and different rapid-beat number. Under the condition of different signal frequency, horizontal wave vector, normal wave number estimation mismatch and source number estimation mismatch, the target orientation performance of each algorithm is simulated and analyzed. In this paper, the advantages and disadvantages and applicability of these algorithms for long linear array direction finding under different shallow water waveguides are discussed. In view of the spatial non-Gao Si characteristics of background noise in complex marine environment, the principle of using high-order cumulants to suppress Gao Si noise is discussed. An algorithm combining subspace intersection algorithm based on normal wave model with high order cumulant is proposed. The simulation results show that under the environmental noise such as Gao Si white noise, Gao Si spatial color noise, Rayleigh white noise and Rayleigh distribution spatial color noise, etc. This algorithm can realize the accurate orientation of the long linear array under the condition of multimode propagation in shallow water waveguide.
【學位授予單位】：國防科學技術(shù)大學
【學位級別】：碩士
【學位授予年份】：2014
【分類號】：P715.5

【參考文獻】

相關(guān)碩士學位論文 前1條

1 華洋;子空間相交方位估計方法性能分析[D];中國海洋大學;2008年

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本文編號：1994280