针对基于平面波声场模型的深海DOA(Direction of Arrival,DOA)估计存在误差的问题,从射线理论出发,建立了多途信道下深海DOA估计的阵列信号模型,推导出了深海多径声线传播时间和相邻阵元声线传播时延差的表征方法,运用解相干DOA估计算法...针对基于平面波声场模型的深海DOA(Direction of Arrival,DOA)估计存在误差的问题,从射线理论出发,建立了多途信道下深海DOA估计的阵列信号模型,推导出了深海多径声线传播时间和相邻阵元声线传播时延差的表征方法,运用解相干DOA估计算法,提高深海DOA估计性能,通过仿真验证了算法的有效性。研究表明,深海DOA估计问题实为多维参数优化问题;充分考虑海洋声场的声传播特性,可以从根本上解决深海DOA估计的误差问题。展开更多
基于信号相位匹配原理,给出了利用由双平行线列阵组成的平面阵进行声源方位估计的奇异值分解算法(Singular Value Decomposition for Signal Phase Matching,SVDSPM),推导了空间谱搜索所需的时延计算公式;分析了双线阵间距对不同频率方...基于信号相位匹配原理,给出了利用由双平行线列阵组成的平面阵进行声源方位估计的奇异值分解算法(Singular Value Decomposition for Signal Phase Matching,SVDSPM),推导了空间谱搜索所需的时延计算公式;分析了双线阵间距对不同频率方位估计精度的影响,从而确定了双线阵的间距;分析了声源频率对方位估计精度的影响;给出了给定频率时方位估计精度与信噪比的关系并与MUSIC算法获得的结果进行了比较;给出了利用平面阵进行低空目标的声探测时存在的声探测盲区的描述方法,并分析了声源的频率、目标初始俯仰角、阵元数、阵型对声探测盲区的影响。仿真结果表明:(1)在低信噪比时SVDSPM算法的方位估计性能优于MUSIC算法;(2)声探测盲区的范围与声源的频率和目标初始俯仰角有关,而与阵元数、阵型无关。声探测盲区的分析和研究为立体阵的设计和方位估计提供了依据。展开更多
A uniform array of scalar-sensors with intersensor spacings over a large aperture size generally offers enhanced resolution and source localization accuracy,but it may also lead to cyclic ambiguity.By exploiting the p...A uniform array of scalar-sensors with intersensor spacings over a large aperture size generally offers enhanced resolution and source localization accuracy,but it may also lead to cyclic ambiguity.By exploiting the polarization information of impinging waves,an electromagnetic vector-sensor array outperforms the unpolarized scalar-sensor array in resolving this cyclic ambiguity.However,the electromagnetic vector-sensor array usually consists of cocentered orthogonal loops and dipoles（COLD）,which is easily subjected to mutual coupling across these cocentered dipoles/loops.As a result,the source localization performance of the COLD array may substantially degrade rather than being improved.This paper proposes a new source localization method with a non-cocentered orthogonal loop and dipole（NCOLD）array.The NCOLD array contains only one dipole or loop on each array grid,and the intersensor spacings are larger than a half-wavelength.Therefore,unlike the COLD array,these well separated dipoles/loops minimize the mutual coupling effects and extend the spatial aperture as well.With the NCOLD array,the proposed method can effciently exploit the polarization information to offer high localization precision.展开更多
文摘针对基于平面波声场模型的深海DOA(Direction of Arrival,DOA)估计存在误差的问题,从射线理论出发,建立了多途信道下深海DOA估计的阵列信号模型,推导出了深海多径声线传播时间和相邻阵元声线传播时延差的表征方法,运用解相干DOA估计算法,提高深海DOA估计性能,通过仿真验证了算法的有效性。研究表明,深海DOA估计问题实为多维参数优化问题;充分考虑海洋声场的声传播特性,可以从根本上解决深海DOA估计的误差问题。
文摘基于信号相位匹配原理,给出了利用由双平行线列阵组成的平面阵进行声源方位估计的奇异值分解算法(Singular Value Decomposition for Signal Phase Matching,SVDSPM),推导了空间谱搜索所需的时延计算公式;分析了双线阵间距对不同频率方位估计精度的影响,从而确定了双线阵的间距;分析了声源频率对方位估计精度的影响;给出了给定频率时方位估计精度与信噪比的关系并与MUSIC算法获得的结果进行了比较;给出了利用平面阵进行低空目标的声探测时存在的声探测盲区的描述方法,并分析了声源的频率、目标初始俯仰角、阵元数、阵型对声探测盲区的影响。仿真结果表明:(1)在低信噪比时SVDSPM算法的方位估计性能优于MUSIC算法;(2)声探测盲区的范围与声源的频率和目标初始俯仰角有关,而与阵元数、阵型无关。声探测盲区的分析和研究为立体阵的设计和方位估计提供了依据。
基金supported by the Scientifc Research Fund of Zhejiang Provincial Education Department(No.Y201225848)the Scientifc and Technological Innovation Programs of Higher Education Institutions in Shanxi(No.2013124)
文摘A uniform array of scalar-sensors with intersensor spacings over a large aperture size generally offers enhanced resolution and source localization accuracy,but it may also lead to cyclic ambiguity.By exploiting the polarization information of impinging waves,an electromagnetic vector-sensor array outperforms the unpolarized scalar-sensor array in resolving this cyclic ambiguity.However,the electromagnetic vector-sensor array usually consists of cocentered orthogonal loops and dipoles（COLD）,which is easily subjected to mutual coupling across these cocentered dipoles/loops.As a result,the source localization performance of the COLD array may substantially degrade rather than being improved.This paper proposes a new source localization method with a non-cocentered orthogonal loop and dipole（NCOLD）array.The NCOLD array contains only one dipole or loop on each array grid,and the intersensor spacings are larger than a half-wavelength.Therefore,unlike the COLD array,these well separated dipoles/loops minimize the mutual coupling effects and extend the spatial aperture as well.With the NCOLD array,the proposed method can effciently exploit the polarization information to offer high localization precision.
