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Theoretical analysis and experimental research on non-cavitation noise modulation mechanism of underwater counter-rotation propeller

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Chinese Journal of Acoustics 2018年第2期37卷 129-145页

作者： ZENG Sai du xuanmin FAN Wei Science and Technology on Underwater Acoustic Antagonizing Laboratory Shanghai Marine Electronic Equipment Research Institute

The underwater counter-rotation propeller non-cavitation noise has an obvious mod- ulation characteristic which is due to the interaction of flow and blade. A modulation mecha- nism is presented in this paper. A sound pressure spectrum model is presented to describe its non-cavitation noise with application of generalized acoustic analogy method, the modulation mechanism is expressed with the improvement of sound pressure model. The power spectrum and modulation spectrum are presented by numerical simulation. Theoretical analysis and nu- merical simulation results are verified by the cavitation tunnel experiment. The modulation model of counter-rotation propeller is beneficial to the prediction modulation characteristics and identification of underwater high-speed vehicles.

关键词： Theoretical analysis and experimental research on non-cavitation noise modulation mechanism of underwater counter-rotation propeller

Research and application of fast-convergent minimum variance distortionless response algorithm

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Chinese Journal of Acoustics 2011年第3期30卷 313-322页

作者： ZHOU Shengzeng du xuanmin Shanghai Marine Electronic Equipment Research Institute Shanghai 201108

The conventional MVDR adaptive beamformer is a high-resolution narrowband beamformer which estimates the optimal beamforming weights using narrowband CSDM of real acoustic field. In practical applications, MVDR algorithm needs long observation time to estimate the covariance matrix. This inherent property makes it difficult to localize fast-moving targets. For wideband signals, MVDR algorithm needs inverting every CSDM which increases the computational demands. For correlated sources, the performance of MVDR will degrade dramatically because the signals will cancel each other. A fast-convergent MVDR algorithm based on subband subarray processing is proposed. The full frequency band is divided into sets of subbands and the line array is divided into sets of subarrays. For every subband the STCM of reduced dimensions is calculated. Then adaptive beamforming weight of fast-convergent MVDR algorithm and spatial spectrum estimation are obtained. At the same time, spatial spectrum estimation can be made for correlated sources using the two-sided spatial smoothing method. Results of simulation and trial data show that the proposed method has high-resolution and near-instantaneous convergence property, two-sided spatial smoothing has satisfactory validity of decorrelation.

关键词： MVDR算法快速收敛最小方差应用自适应波束形成无失真最优波束形成空间谱估计

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基于线谱特征的三元组拖线阵左右舷分辨

声学学报 2009年第4期34卷 296-302页

作者：朱代柱杜选民上海交通大学船舶海洋与建筑工程学院上海200240 上海船舶电子设备研究所上海201108

传统的三元组拖线阵在分辨目标左右舷时利用左、右两侧的宽带能量之比,该技术在通常情况下能够较好地完成使命,但在实际应用中可能会遇到一些困难。本文针对两种影响其左右舷分辨结果的情况做了分析:一种是弱信噪比情况,另一种是另一舷... 详细信息

传统的三元组拖线阵在分辨目标左右舷时利用左、右两侧的宽带能量之比,该技术在通常情况下能够较好地完成使命,但在实际应用中可能会遇到一些困难。本文针对两种影响其左右舷分辨结果的情况做了分析:一种是弱信噪比情况,另一种是另一舷侧存在强干扰目标的情况。针对这两种情况,通过对左、右舷频谱特征的分析,提出了利用线谱特征提取结果分辨目标左、右舷的新技术,显著降低了左右舷分辨功能对输入信噪比的要求。仿真和对海上实验数据的处理结果验证了该方法的稳健性和有效性,可望应用于工程实践中。为了使该技术能够适用于更低的信噪比条件,本文还提出了一种简单实用的线谱增强技术。

关键词：左右舷分辨线谱特征拖线阵三元组增强技术信噪比干扰目标频谱特征

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快速收敛最小方差无畸变响应算法研究及应用

声学学报 2009年第6期34卷 515-520页

作者：周胜增杜选民上海船舶电子设备研究所上海201108

常规最小方差无畸变响应(MVDR)自适应波束形成是一种高分辨窄带波束形成器,它是利用实际声场的窄带互谱密度矩阵(CSDM)估计出自适应波束形成权向量。在实际应用中,MVDR算法需要较长的观测时间估计协方差矩阵,不利于对高速运动目标进行定... 详细信息

常规最小方差无畸变响应(MVDR)自适应波束形成是一种高分辨窄带波束形成器,它是利用实际声场的窄带互谱密度矩阵(CSDM)估计出自适应波束形成权向量。在实际应用中,MVDR算法需要较长的观测时间估计协方差矩阵,不利于对高速运动目标进行定位;对于宽带目标信号,MVDR算法需要对每一个CSDM进行求逆运算,计算量较大;在相干源条件下,目标信号之间会发生"对消"现象,MVDR算法性能急剧恶化。本文提出了基于子带子阵处理的快速收敛MVDR自适应波束形成方法。首先将全频带划分成一组子带,将接收线阵划分成一组子阵,然后对每一子带计算降维的驾驶协方差矩阵(STCM),从而得到快速收敛MVDR自适应波束形成的权值和空间谱估计结果。同时采用双向空间平滑方法对相干源进行MVDR空间谱估计。仿真和海试数据处理结果表明该算法在保证高分辨力的同时,具有瞬时收敛的性能,双向空间平滑技术具有良好的解相干性能。

关键词：最小方差无畸变响应 MVDR算法快速收敛自适应波束形成应用空间谱估计协方差矩阵算法性能

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稳健的子带子阵级导向最小方差波束形成算法

声学学报 2019年第4期44卷 707-714页

作者：周胜增杜选民上海船舶电子设备研究所

导向最小方差(STMV)波束形成是一种利用导向协方差矩阵获得自适应权值的方法,具有快速收敛特性.常规的稳健导向最小方差(RSTMV)波束形成算法在处理宽频带信号时,性能下降明显.为了改善算法的性能,结合频域子带划分和空域子阵划分技术,... 详细信息

导向最小方差(STMV)波束形成是一种利用导向协方差矩阵获得自适应权值的方法,具有快速收敛特性.常规的稳健导向最小方差(RSTMV)波束形成算法在处理宽频带信号时,性能下降明显.为了改善算法的性能,结合频域子带划分和空域子阵划分技术,提出一种多子带不确定集独立约束的稳健子阵级STMV波束形成算法。通过频域子带划分可对不同子带的导向向量误差范数边界进行约束,计算出各子带对应的对角加载量,得到稳健的子带级最小方差波束形成算法权向量;同时采用子阵技术进行降维处理,可进一步增加划分子带的数目,从而提高算法的性能并有效降低计算复杂度,最终得到一种稳健的子带子阵级STMV波束形成算法。理论分析和仿真结果表明,在阵列导向向量存在误差的情况下,该算法在干扰方向形成的零陷最深,且零陷波束宽度最窄,输出信噪比接近理论值,因此性能最佳.实际海试数据处理表明,在强干扰目标存在时,弱目标输出信干噪比较RSTMV算法可提高4 dB,较常规波束形成可提高10 dB,在角度分辨力和算法复杂度方面得到有效改善,同时可以保证目标功率无失真输出。

关键词：波束形成算法子阵划分最小方差子带稳健常规波束形成干扰目标自适应权值

The port/starboard discrimination based on line-spectrum character in towed line array with hydrophone triplets

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Chinese Journal of Acoustics 2011年第1期30卷 62-72页

作者： ZHU Daizhu du xuanmin Shanghai Marine Electronic Equipment Research Institute Shanghai 201108 School of Naval Architecture Ocean and Civil EngineeringShanghai Jiaotong University Shanghai 200240

The energy ratio of broadband signal is utilized for port/starboard discrimination in towed line array with hydrophone triplets in tradition. It works well in most conditions except for two cases： One is low signal to noise ratio（SNR）, and the other is that there is a stronger interference lied on the other side of the line array with approximate bearing angles. A method called line-spectrum character extracting is proposed to discriminate port/starboard for these two cases in this paper, and the SNR needed for port/starboard discrimination is reduced significantly. Simulation and the sea-trial data are analyzed to show that the method is stable and valid, and is expected to be applied in real towed line array sonar. A line-spectrum enhancing technology with lower calculation complexity and stable validity is proposed to ensure the application of this method in lower SNR condition.

关键词： line The port/starboard discrimination based on line-spectrum character in towed line array with hydrophone triplets

利用正弦调频信号的宽带速度敏感特性抑制混响

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声学学报 2022年第1期47卷 16-26页

作者：周胜增杜选民上海船舶电子设备研究所上海201108

有源声呐探测水中低速目标时,混响与目标回波的频率接近,目标回波与混响分离困难。根据运动目标与产生混响的散射体在速度域的差异,利用正弦调频信号(SFM)的速度敏感特性实现目标回波与混响的有效分离。推导了 SFM信号宽带混响抑制能力... 详细信息

有源声呐探测水中低速目标时,混响与目标回波的频率接近,目标回波与混响分离困难。根据运动目标与产生混响的散射体在速度域的差异,利用正弦调频信号(SFM)的速度敏感特性实现目标回波与混响的有效分离。推导了 SFM信号宽带混响抑制能力与速度分辨模糊之间的约束关系,建立了波形优化设计的搜索模型。通过多普勒滤波处理将数据从频率域统一转换至速度域,设定合适的速度门限,去除静止的混响成分。通过仿真分析了 SFM信号的混响抑制能力、调制指数和带宽的关系,在设定的速度范围内平均混响抑制能力较连续波(CW)信号可提高7.5 dB。动目标试验数据的处理结果表明了该方法能够抑制混响中强杂波造成的虚警,通过速度差异性可有效提高对动目标的检测能力。

关键词：调制指数连续波多普勒滤波混响抑制散射体敏感特性目标回波约束关系

Performance of passive target tracking using bearing-frequency and bearings of multiple arrays

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Chinese Journal of Acoustics 2002年第2期21卷 124-136页

作者： du xuanmin, YAO Lan (Shanghai Marine Electronic Equipment Research Institute Shanghai 200025) Shanghai Marine Electronic Equipment Research Institute Shanghai 200025

Two target motion analysis (TMA) methods using multi-dimension information are studied, one is TMA with bearing-frequency and the other is TMA with multiple arrays. The optimization algorithm combining Gauss-Newton (G-N) method with Levenberg-Marquardt (L- M) method is applied to analyze the performance of target tracking with maximum likelihood estimation(MLE), and Monte Carlo experiments are presented. The results show that although the TMA with multi-dimension information have eliminated the maneuvers needed by conven- tional bearing-only TMA, but the application are not of universality

关键词： TMA Performance of passive target tracking using bearing-frequency and bearings of multiple arrays MLE CRLB

水下对转桨无空化噪声调制理论分析与试验研究

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声学学报 2017年第6期42卷 641-651页

作者：曾赛杜选民范威上海船舶电子设备研究所水声对抗技术重点实验室上海201108

水下对转桨无空化噪声由流场-桨叶相互作用引起,调制特性是水下对转桨无空化噪声的重要特征,本文研究了水下对转桨无空化辐射噪声调制机理。首先利用广义声类比方法得到了无空化条件下水下对转桨的远场声压谱,建立了水下对转桨无空化噪... 详细信息

水下对转桨无空化噪声由流场-桨叶相互作用引起,调制特性是水下对转桨无空化噪声的重要特征,本文研究了水下对转桨无空化辐射噪声调制机理。首先利用广义声类比方法得到了无空化条件下水下对转桨的远场声压谱,建立了水下对转桨无空化噪声的调制模型,然后数值仿真了模型对转桨无空化噪声的功率谱和调制谱,最后在空泡水筒中进行了模型对转桨的无空化噪声测量试验,数值仿真结果和试验验证了调制模型的准确性。该模型对于水下对转桨无空化噪声调制特性预报及目标识别具有重要价值.

关键词：无空化噪声调制调制特性空化噪声数值仿真调制深度噪声测量制谱理论分析目标识别