基于反射镜水下声成像系统建模和仿真

《基于反射镜水下声成像系统建模和仿真》由会员上传分享，免费在线阅读，更多相关内容在学术论文-天天文库。

1、基于反射镜的水下声成像系统建模与仿真摘要在水声探测领域，环境噪声被当作一种降低声呐性能的干扰，大量对主被动声呐系统的研究工作是如何去抑制噪声，而在利用水下噪声作为唯一“照明”对目标进行探测和成像的理论中，环境噪声被当作有用的信息。论文的主要工作是对声学成像系统的建模和仿真。论文研究了声学成像的基本原理，构建了成像系统，由一个凹面镜和放置在凹面镜像平面上的平面基阵组成声学镜头，利用这个有聚焦作用的声学镜头聚焦接收目标的散射声，从而获得目标的可视图像。论文基于Helmholtz积分，利用Kirchhoff近似建立了声学镜头接收信号模型和目标散

2、射声模型，并采用稳定相位法计算目标散射声。水下噪声场模型是由互相独立的稳定单频点源构成，通过改变源的数量和位置得到不同噪声场。论文按照三个子模型间的内在连接关系获得水下噪声成像系统的模型。论文分别对刚球目标和方形刚板目标进行了大量成像仿真实验，探讨了噪声入射方向、频率和目标大小对成像效果的影响，获得了一些可供参考的仿真数据。关键词：声学成像；水下噪声成像；声学镜头；声散射模型；水下噪声场；Helmholtz积分；Kirchhoff近似：稳定相位法基于反射镜的水下声成像系统建模与仿真ABSTRACTInthefieldofunderwate

3、racousticdetection,ambientnoiseisconsideredallinterferencewhichdegradestheperformanceofsonar．Agreatbodyofworkonactiveandpassivesonarsystemsishowtorestrainthenoise，whileambientnoiseisregardedasusefulinformationwhenusingunderwaternoiseasthesoleilluminationfortargetdetection

4、andimaging．Themainpartsofthisthesisaremodelingandsimulationofacousticdaylightimagingsystem．Inthethesis，thebasicprincipleofacousticdaylightimagingisresearchedandtheimagingsystemisconstructed．Theacousticlensconsistsofaconcavemirrorandaplanartransducerarraylocatedattheimagep

5、laneoftheconcavemirror,andthewavescatteringfromatargetwillbefocusedandreceivedbytheacousticlenstoachievethevisibleimageofthetarget．BasedontheHelmholtzintegralwiththeKirchhoffapproximation,thesignalreceivingmodelofacousticlensandtheacousticscatteringmodelofthetargethavebee

6、nmade，andstationaryphasemethodisusedtoevaluatethescatteringwave．Themodelofunderwaternoisefieldiscomposedofthestablesingle-frequencypointsourcesindependentfromeachother，anddifferentnoisefieldCanbeobtainedbychangingthenumberandthepositionofthesources．Accordingtotheinternalr

7、elationshipbetweenthethreesub—models，themodelofacousticdaylightimagingsystemisconnected．Lotsofsimulationsonimagingofrigidsphereandsquarerigidboardhavedonerespectively．Theperformanceoftheacousticdaylightimagingsystemasafunctionofincidentdirectionofthenoise，frequencyoftheno

8、iseandtargetsizeisdiscussed，andsomevaluablesimulationdataforreferenceareobtained．Keywords：acoust