矢量混响特性研究
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摘要
混响信号是声波传播过程中随机起伏的海面或不平整的海底或海水媒质内部的随机不均匀性形成的反向散射在接收点所收到的声信号。混响包含有水下波导声学和海洋特性的信息，一直是理论和试验研究的课题。混响是伴随发射信号产生的，是主动声纳系统主要的背景干扰，大大限制了声纳的作用距离和参数估计性能。为了改善主动声纳的工作性能，须对海洋混响特性进行研究。
长期以来，国内外学者对海洋混响的研究，都是针对声压这一物理量而言的。矢量水听器的问世，改变了这种源信息的单一性，它可以同时测量声场中的声压p(t)和质点振速的三个正交分量v_x(t)，v_y(t)，v_z(t)，比单纯的声压p(t)含有更多的信息，可以更充分、更全面地描述混响这一散射场。
本文以混响理论和矢量声学理论为基础，首先利用单元散射模型和点散射模型对海洋混响进行了研究和仿真，结果表明：矢量水听器可以抑制混响。其次，结合浅海低频矢量混响数据，从频率，概率分布，声压和振速的时空相关，混响信号的脉间相关和拷贝相关等统计特性进行了分析，结果表明：界面散射在浅海低频混响中起着重要作用，且浅海混响是各向异性的，存在明显的确定分量；混响场声压和振速的三个分量存在一定的相关性，其声压和振速水平分量的相关性比声压和振速垂直分量的相关性弱。然后，利用测试数据和仿真模型，分析了信号的Itakura距离和时频特性(如瞬时频率、WV谱)，结果表明：混响是一个局部可平稳化的随机过程，其振速水平分量的WV谱比垂直分量明显。最后，从混响的矢量特性(如瞬时声能流)，相干特性和空间特性以及单矢量水听器和矢量阵的混响抑制能力等方面对海试数据进行了分析，结果表明：矢量水听器可以全面地获取混响场的空间特性，有利于混响场产生机理和散射特性的研究；矢量水听器的声能流处理可抑制混响6-SdB，4元压差式矢量阵相对常规声压阵可抑制混响约8dB。
Reverberation is all back-scatter acoustic signal for the random fluctuant surface and bottom, the disaccord of seawater during acoustic wave transmiting. Sound reverberation is a source of information on acoustic and oceanological properties of underwater waveguide and has been the subject of a great many theoretical and experimental investigations. Reverberation which occurs after emission signal, is primary interference for the active sonar, consumedly limits the operation distance and parameter estimate of the active sonar. It is necessary that the characters of reverberation are studied to improve the operation performance.
While up to now, all researches on reverberation exceptionally measured the sound pressure. The vector sensor which alters oneness of the source information may measure the sound pressure p(t) and the orthogonal components of the particle velocity, v_x(t) ,v_y(t), v_z(t), data simultaneously at a given point in the acoustic field. Therefore, it has more information and may more comprehensively describe the sound scattering than the onefold sound pressure p(t).
Based on theories of the sound scattering and the vector acoustic, the vector-sensor reverberation is researched in this thesis. Firstly, based on the cell scattering model and the point scattering model, the vector-sensor reverberation is researched and simulated. it shows that the vector sensor may restrain reverberation. Secondly, the low-frequency data of vector sensor reverberation in shallow sea are analyzed from the frequency, the probability, the time-space correlation of the sound pressure and the particle velocity, inter-pulse and copy correlation, it shows that the surface sound scattering is a main contributor to reverberation in shallow sea, the reverberation is distinctly anisotropic and has obvious certainty components, the sound pressure and the three orthogonal components of the particle velocity has weak correlation, and the correlation between the sound pressure p(t) and component of the particle velocity v_x(t) or v_y(t) appears to be much less than the correlation between p(t) and v_z(t). Thirdly, based on experimentation data and simulation model, Itakura distance and the time-frequency property (such as instantaneous frequency, the Wigner-Ville spectrum) are computed and researched, it shows that reverberation process is a local stable stochastic process, the WV spectrum of v_x(t) or v_y(t) is more distinct than v_z(t). Lastly, vector characteristics (such as the sound energy flux density), the coherence, directionality properties and the anti-reverberation capability of the single vector sensor and the vector line arrays are studied and analyzed. It shows that the vector sensor may more roundly and better obtain the spatial characteristics than the conventional hydrophone, and be propitious to research the mechanism of reverberation and the scattering characteristics, the vector sensor may suppress the reverberation contamination by 6-8 dB, the four element line arrays of pressure-gradient hydrophones have more about 8 dB suppression capability than the conventional hydrophone line array.
长期以来，国内外学者对海洋混响的研究，都是针对声压这一物理量而言的。矢量水听器的问世，改变了这种源信息的单一性，它可以同时测量声场中的声压p(t)和质点振速的三个正交分量v_x(t)，v_y(t)，v_z(t)，比单纯的声压p(t)含有更多的信息，可以更充分、更全面地描述混响这一散射场。
本文以混响理论和矢量声学理论为基础，首先利用单元散射模型和点散射模型对海洋混响进行了研究和仿真，结果表明：矢量水听器可以抑制混响。其次，结合浅海低频矢量混响数据，从频率，概率分布，声压和振速的时空相关，混响信号的脉间相关和拷贝相关等统计特性进行了分析，结果表明：界面散射在浅海低频混响中起着重要作用，且浅海混响是各向异性的，存在明显的确定分量；混响场声压和振速的三个分量存在一定的相关性，其声压和振速水平分量的相关性比声压和振速垂直分量的相关性弱。然后，利用测试数据和仿真模型，分析了信号的Itakura距离和时频特性(如瞬时频率、WV谱)，结果表明：混响是一个局部可平稳化的随机过程，其振速水平分量的WV谱比垂直分量明显。最后，从混响的矢量特性(如瞬时声能流)，相干特性和空间特性以及单矢量水听器和矢量阵的混响抑制能力等方面对海试数据进行了分析，结果表明：矢量水听器可以全面地获取混响场的空间特性，有利于混响场产生机理和散射特性的研究；矢量水听器的声能流处理可抑制混响6-SdB，4元压差式矢量阵相对常规声压阵可抑制混响约8dB。
Reverberation is all back-scatter acoustic signal for the random fluctuant surface and bottom, the disaccord of seawater during acoustic wave transmiting. Sound reverberation is a source of information on acoustic and oceanological properties of underwater waveguide and has been the subject of a great many theoretical and experimental investigations. Reverberation which occurs after emission signal, is primary interference for the active sonar, consumedly limits the operation distance and parameter estimate of the active sonar. It is necessary that the characters of reverberation are studied to improve the operation performance.
While up to now, all researches on reverberation exceptionally measured the sound pressure. The vector sensor which alters oneness of the source information may measure the sound pressure p(t) and the orthogonal components of the particle velocity, v_x(t) ,v_y(t), v_z(t), data simultaneously at a given point in the acoustic field. Therefore, it has more information and may more comprehensively describe the sound scattering than the onefold sound pressure p(t).
Based on theories of the sound scattering and the vector acoustic, the vector-sensor reverberation is researched in this thesis. Firstly, based on the cell scattering model and the point scattering model, the vector-sensor reverberation is researched and simulated. it shows that the vector sensor may restrain reverberation. Secondly, the low-frequency data of vector sensor reverberation in shallow sea are analyzed from the frequency, the probability, the time-space correlation of the sound pressure and the particle velocity, inter-pulse and copy correlation, it shows that the surface sound scattering is a main contributor to reverberation in shallow sea, the reverberation is distinctly anisotropic and has obvious certainty components, the sound pressure and the three orthogonal components of the particle velocity has weak correlation, and the correlation between the sound pressure p(t) and component of the particle velocity v_x(t) or v_y(t) appears to be much less than the correlation between p(t) and v_z(t). Thirdly, based on experimentation data and simulation model, Itakura distance and the time-frequency property (such as instantaneous frequency, the Wigner-Ville spectrum) are computed and researched, it shows that reverberation process is a local stable stochastic process, the WV spectrum of v_x(t) or v_y(t) is more distinct than v_z(t). Lastly, vector characteristics (such as the sound energy flux density), the coherence, directionality properties and the anti-reverberation capability of the single vector sensor and the vector line arrays are studied and analyzed. It shows that the vector sensor may more roundly and better obtain the spatial characteristics than the conventional hydrophone, and be propitious to research the mechanism of reverberation and the scattering characteristics, the vector sensor may suppress the reverberation contamination by 6-8 dB, the four element line arrays of pressure-gradient hydrophones have more about 8 dB suppression capability than the conventional hydrophone line array.
引文
[1] R．J．Urick著．水声原理．洪申译．哈尔滨船舶工程学院出版社，1990：190-230页
[2] B．B．奥里雪夫斯基．海洋混响的统计特性．科学出版社，1977
[3] 李风华，金国亮，张仁和．浅海相干混响理论与混响强度的振荡现象．中国科学．2000，30(6)：559-566页
[4] 葛凤翔，惠俊英．界面混响信号的仿真研究．电子与信息学报．2001，23(12)：1291-1297页
[5] 王新勇．宽带多频动目标检测．哈尔滨工程大学硕士学位论文．2000：9-14页，16-20页
[6] 葛凤翔．智能诱饵中“边收边发”技术研究．哈尔滨工程大学硕士学位论文．1999：5-9页，17-27页
[7] 王之程，陈宗岐，于讽，刘文帅．舰船噪声测量与分析．国防工业出版社，2002：166-187页
[8] 孙贵青，李启虎．声矢量传感器研究进展．声学学报．2004，29(6)：481-489页
[9] V.A.Shchurov. "Vector Acoustics of the Ocean". Vladivostok Dalhuka. 2003
[10] 蔡平，郭龙祥，惠俊英．矢量传感器海底混响仿真模型．声学技术．2004，23：66-69页
[11] 郭龙祥，蔡平，惠俊英．海底混响声压和振速相关特性分析．声学技术．2004，23：268-281页
[12] 王志伟．长脉冲信号混响时空相关特性研究及抗混响技术探索．GF报告．2004：23-26页
[13] 杜敬林．试验海区混响统计特性时空相关特性及混响干扰抑制技术研究．GF报告．2005：19-24页
[14] 刘伯胜．水声学原理．哈尔滨工程大学出版社，1997：187-212页
[15] R．J．Urick著．水声建模．崔绪生译．船舶工业总公司第七研究院第七零五研究所．1995：122—135页
[16] B．B．奥里雪夫斯基．声纳统计方法．国防工业出版社，1984：56-78页
[17] 布列霍夫斯基．海洋声学．科学出版社，1983：105-108页，179-378页
[18] 惠俊英．水下声信道．国防工业出版社，1992：99-109页
[19] 何祚镛，赵玉芳．声学理论基础．国防工业出版社，1981：51-55页
[20] 孙贵青．矢量水听器检测技术研究．哈尔滨工程大学博士学位论文．2001年
[21] Benjiamin A.Cray, Albert H.Nuttall. "Directivity factors for linear arrays of velocity sensors". JASA. 2001, 110(1):324-331P
[22] 吴承义．用射线方法计算浅海混响平均强度(1)．声学学报．1979(4)：114-119页
[23] Dale D.Ellis. "A shallow-water normal-mode reverberation model". JASA. 1995, 97(5):2804-2814P
[24] 赵航芳．浅海混响实验数据垂直指向性简正波建模分析．声学与电子工程．2001(4)：10-15页
[25] 张仁和，李风华．浅海声传播的波束位移射线简正波理论．中国科学．1999，29(3)：241-251页
[26] 王新晓．海洋混响仿真技术研究．声学与电子工程．2002(3)：27-30页
[27] 方世良．海洋混响信号的序贯仿真．声学技术．1996，15(3)：101-104页
[28] 赵航芳．混响背景下的信号检测．哈尔滨工程大学学报．2004，25(1)：34-37页
[29] 祝献．混响背景下宽带信号的检测．声学与电子工程．2004(1)：1-5页
[30] Yevgeniy Y.Dorfman, lra Dyer. "Monostatic and bistatic reverberation statistics west of the Mid-Atlantic Ridge". JASA. 1999,106(4): 1755-1764P
[31] Robert C.Higgins, James T.Francis, Ronald W.Hoy. "Implementation and validation of a model for surface reverberation".JASA. 1977, 61 (2): 499-507P
[32] William J.Jobst,Talivaldis I.Smits."Mathematical model for volume reverberation:experiment and simulation". JASA. 1974, 55(2):227-236P
[33] Gary R.Wilson, Marshall E.Frazer. "Horizontal covariance of surface reverberation:Comparison of a point-scatter model to experiment". JASA. 1983, 73(3): 749-760P
[34] Pierre Faure. "Theoretical Model of Reverberation Noise". JASA. 1954, 36(2):259-265P
[35] 朱华，黄辉宁．随机信号分析．北京理工大学出版社，1990：201-204页
[36] 张贤达，保铮．非平稳信号分析与处理．国防工业出版社，2001：19页
[37] Malcolm Hawkes, Member."Acoustic Vector-Sensor Correlations in Ambient Noise". IEEE J.of Oceanic Engineering. 2001, 26(3):337-347P
[38] 孟洪．矢量水听器及联合信号处理研究．哈尔滨工程大学硕士学位论文．2002
[39] 孙贵青，杨德森，时胜国．基于矢量传感器的声压和质点振速的空间相关系数．声学学报．2003，28(6)：509-513页
[40] Gary R.Wilson. "Comparison of the measured covariance of surface reverberation for horizontal and vertical arrays". JASA. 1982, 72(6): 1905-1910P
[41] 朱埜．主动声呐信息检测原理．海洋出版社，1990：287-321页
[42] 姜永珉．水中目标回波亮点时空相关与脉间相关特性研究．舰船科学技术．2002，24(1)：30-34页
[43] 王明洲，赫重阳，黄晓文．水下高频目标回波的脉间相关和复本相关特性实验研究．鱼类技术．2002，10(3)：44-49页
[44] V.A.Shchurov. "Coherent and diffusive fields of underwater Acoustic ambient noise". JASA. 1991, 90(2): 991-1001P
[45] 雷桑诺夫，布列霍夫斯基．海洋声学基础．海洋出版社，1987：207-246页
[2] B．B．奥里雪夫斯基．海洋混响的统计特性．科学出版社，1977
[3] 李风华，金国亮，张仁和．浅海相干混响理论与混响强度的振荡现象．中国科学．2000，30(6)：559-566页
[4] 葛凤翔，惠俊英．界面混响信号的仿真研究．电子与信息学报．2001，23(12)：1291-1297页
[5] 王新勇．宽带多频动目标检测．哈尔滨工程大学硕士学位论文．2000：9-14页，16-20页
[6] 葛凤翔．智能诱饵中“边收边发”技术研究．哈尔滨工程大学硕士学位论文．1999：5-9页，17-27页
[7] 王之程，陈宗岐，于讽，刘文帅．舰船噪声测量与分析．国防工业出版社，2002：166-187页
[8] 孙贵青，李启虎．声矢量传感器研究进展．声学学报．2004，29(6)：481-489页
[9] V.A.Shchurov. "Vector Acoustics of the Ocean". Vladivostok Dalhuka. 2003
[10] 蔡平，郭龙祥，惠俊英．矢量传感器海底混响仿真模型．声学技术．2004，23：66-69页
[11] 郭龙祥，蔡平，惠俊英．海底混响声压和振速相关特性分析．声学技术．2004，23：268-281页
[12] 王志伟．长脉冲信号混响时空相关特性研究及抗混响技术探索．GF报告．2004：23-26页
[13] 杜敬林．试验海区混响统计特性时空相关特性及混响干扰抑制技术研究．GF报告．2005：19-24页
[14] 刘伯胜．水声学原理．哈尔滨工程大学出版社，1997：187-212页
[15] R．J．Urick著．水声建模．崔绪生译．船舶工业总公司第七研究院第七零五研究所．1995：122—135页
[16] B．B．奥里雪夫斯基．声纳统计方法．国防工业出版社，1984：56-78页
[17] 布列霍夫斯基．海洋声学．科学出版社，1983：105-108页，179-378页
[18] 惠俊英．水下声信道．国防工业出版社，1992：99-109页
[19] 何祚镛，赵玉芳．声学理论基础．国防工业出版社，1981：51-55页
[20] 孙贵青．矢量水听器检测技术研究．哈尔滨工程大学博士学位论文．2001年
[21] Benjiamin A.Cray, Albert H.Nuttall. "Directivity factors for linear arrays of velocity sensors". JASA. 2001, 110(1):324-331P
[22] 吴承义．用射线方法计算浅海混响平均强度(1)．声学学报．1979(4)：114-119页
[23] Dale D.Ellis. "A shallow-water normal-mode reverberation model". JASA. 1995, 97(5):2804-2814P
[24] 赵航芳．浅海混响实验数据垂直指向性简正波建模分析．声学与电子工程．2001(4)：10-15页
[25] 张仁和，李风华．浅海声传播的波束位移射线简正波理论．中国科学．1999，29(3)：241-251页
[26] 王新晓．海洋混响仿真技术研究．声学与电子工程．2002(3)：27-30页
[27] 方世良．海洋混响信号的序贯仿真．声学技术．1996，15(3)：101-104页
[28] 赵航芳．混响背景下的信号检测．哈尔滨工程大学学报．2004，25(1)：34-37页
[29] 祝献．混响背景下宽带信号的检测．声学与电子工程．2004(1)：1-5页
[30] Yevgeniy Y.Dorfman, lra Dyer. "Monostatic and bistatic reverberation statistics west of the Mid-Atlantic Ridge". JASA. 1999,106(4): 1755-1764P
[31] Robert C.Higgins, James T.Francis, Ronald W.Hoy. "Implementation and validation of a model for surface reverberation".JASA. 1977, 61 (2): 499-507P
[32] William J.Jobst,Talivaldis I.Smits."Mathematical model for volume reverberation:experiment and simulation". JASA. 1974, 55(2):227-236P
[33] Gary R.Wilson, Marshall E.Frazer. "Horizontal covariance of surface reverberation:Comparison of a point-scatter model to experiment". JASA. 1983, 73(3): 749-760P
[34] Pierre Faure. "Theoretical Model of Reverberation Noise". JASA. 1954, 36(2):259-265P
[35] 朱华，黄辉宁．随机信号分析．北京理工大学出版社，1990：201-204页
[36] 张贤达，保铮．非平稳信号分析与处理．国防工业出版社，2001：19页
[37] Malcolm Hawkes, Member."Acoustic Vector-Sensor Correlations in Ambient Noise". IEEE J.of Oceanic Engineering. 2001, 26(3):337-347P
[38] 孟洪．矢量水听器及联合信号处理研究．哈尔滨工程大学硕士学位论文．2002
[39] 孙贵青，杨德森，时胜国．基于矢量传感器的声压和质点振速的空间相关系数．声学学报．2003，28(6)：509-513页
[40] Gary R.Wilson. "Comparison of the measured covariance of surface reverberation for horizontal and vertical arrays". JASA. 1982, 72(6): 1905-1910P
[41] 朱埜．主动声呐信息检测原理．海洋出版社，1990：287-321页
[42] 姜永珉．水中目标回波亮点时空相关与脉间相关特性研究．舰船科学技术．2002，24(1)：30-34页
[43] 王明洲，赫重阳，黄晓文．水下高频目标回波的脉间相关和复本相关特性实验研究．鱼类技术．2002，10(3)：44-49页
[44] V.A.Shchurov. "Coherent and diffusive fields of underwater Acoustic ambient noise". JASA. 1991, 90(2): 991-1001P
[45] 雷桑诺夫，布列霍夫斯基．海洋声学基础．海洋出版社，1987：207-246页