Pub Date : 1900-01-01DOI: 10.1109/COA.2016.7535714
Jin Mengqun, Ge Huiliang, Z. Zili
A 3-dimentional fiber-optic vector hydrophone, with many advantages including high sensitivity, large dynamic range, intrinsic immunity to electromagnetic interference and light weight, is becoming a hotspot of new-style vector sensors. For array applications, this review has discussed the finite element methods and experimental results of the hydrophone. A fiber-optic flexural disk vector hydrophone has been developed and related metrology aspects of measurement have been demonstrated. To figure out the issue of fiber-optic vector hydrophone, we optimize the hydrophone with an optical scheme, mechanism construction and sensing properties. In the optical scheme aspect, we replace the traditional optical devices with low reflectivity a fiber Bragg grating to simplify the optical scheme and minimize the sensor size. In the sensing properties aspect, we optimize the sensing parameter of the fiber-optic acceleration component with finite element analysis. The influence factor of the acoustic performance is discussed. In the mechanism construction aspect, a 3-dimetional isolated acceleration sensing structure is presented with a fiber-optic pressure component outside. A column type fiber optic vector hydrophone sample is then introduced. The size of the hydrophone is φ60mm×125mm. The acceleration sensitivity of the acceleration component is 22.5dB ref.1rad/g; and, with fluctuation of ±1.5dB ref.1rad/g at the range from 100Hz to 1000Hz. The equivalent pressure phase sensitivity in water of each axis is -183.5dB ref. 1rad/uPa@100Hz ~ -159dB ref. 1rad/uPa@1000Hz; and, with fluctuation of ±1.5dB at the range from 100 to 1000Hz. The cross talk of each axis is below -20dB. The pressure sensitivity of the pressure component is -131.8 ref. 1rad/uPa; and, with fluctuation of ±1dB. We also test the directionality of the 3 acceleration component and pressure component. It has a good directionality performance and the maximum value non uniformity of the acceleration component is below 1dB.
{"title":"The optimal design of a 3D column type fiber-optic vector hydrophone","authors":"Jin Mengqun, Ge Huiliang, Z. Zili","doi":"10.1109/COA.2016.7535714","DOIUrl":"https://doi.org/10.1109/COA.2016.7535714","url":null,"abstract":"A 3-dimentional fiber-optic vector hydrophone, with many advantages including high sensitivity, large dynamic range, intrinsic immunity to electromagnetic interference and light weight, is becoming a hotspot of new-style vector sensors. For array applications, this review has discussed the finite element methods and experimental results of the hydrophone. A fiber-optic flexural disk vector hydrophone has been developed and related metrology aspects of measurement have been demonstrated. To figure out the issue of fiber-optic vector hydrophone, we optimize the hydrophone with an optical scheme, mechanism construction and sensing properties. In the optical scheme aspect, we replace the traditional optical devices with low reflectivity a fiber Bragg grating to simplify the optical scheme and minimize the sensor size. In the sensing properties aspect, we optimize the sensing parameter of the fiber-optic acceleration component with finite element analysis. The influence factor of the acoustic performance is discussed. In the mechanism construction aspect, a 3-dimetional isolated acceleration sensing structure is presented with a fiber-optic pressure component outside. A column type fiber optic vector hydrophone sample is then introduced. The size of the hydrophone is φ60mm×125mm. The acceleration sensitivity of the acceleration component is 22.5dB ref.1rad/g; and, with fluctuation of ±1.5dB ref.1rad/g at the range from 100Hz to 1000Hz. The equivalent pressure phase sensitivity in water of each axis is -183.5dB ref. 1rad/uPa@100Hz ~ -159dB ref. 1rad/uPa@1000Hz; and, with fluctuation of ±1.5dB at the range from 100 to 1000Hz. The cross talk of each axis is below -20dB. The pressure sensitivity of the pressure component is -131.8 ref. 1rad/uPa; and, with fluctuation of ±1dB. We also test the directionality of the 3 acceleration component and pressure component. It has a good directionality performance and the maximum value non uniformity of the acceleration component is below 1dB.","PeriodicalId":155481,"journal":{"name":"2016 IEEE/OES China Ocean Acoustics (COA)","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132962640","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1900-01-01DOI: 10.1109/COA.2016.7535742
Zhang Youwen, Xiao Shuang, Liu Lu, Sun Da-jun
In this paper, a novel variable multiple step-size least mean square (VMSSLMS) adaptive filter algorithm with the l0-norm constraint is proposed, which both allows the step-size to vary for different taps and includes a sparsity constraint in the cost function. When channel changes suddenly, the filter can track the specific tap-weight fast to adapt to the variation of the channel. The l0-norm constraint can take advantage of the sparse property, thus it can improve the performance of the sparse channel estimation. Simulations show that compared with the existing algorithms, the proposed algorithm performs better in the sparse channels with a faster convergence rate and a lower misadjustment. System identification tests with the proposed algorithm for the channel obtained from South ocean also show superior performance.
{"title":"A variable multiple step-size LMS algorithm with l0-norm","authors":"Zhang Youwen, Xiao Shuang, Liu Lu, Sun Da-jun","doi":"10.1109/COA.2016.7535742","DOIUrl":"https://doi.org/10.1109/COA.2016.7535742","url":null,"abstract":"In this paper, a novel variable multiple step-size least mean square (VMSSLMS) adaptive filter algorithm with the l0-norm constraint is proposed, which both allows the step-size to vary for different taps and includes a sparsity constraint in the cost function. When channel changes suddenly, the filter can track the specific tap-weight fast to adapt to the variation of the channel. The l0-norm constraint can take advantage of the sparse property, thus it can improve the performance of the sparse channel estimation. Simulations show that compared with the existing algorithms, the proposed algorithm performs better in the sparse channels with a faster convergence rate and a lower misadjustment. System identification tests with the proposed algorithm for the channel obtained from South ocean also show superior performance.","PeriodicalId":155481,"journal":{"name":"2016 IEEE/OES China Ocean Acoustics (COA)","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125310008","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1900-01-01DOI: 10.1109/COA.2016.7535681
Yu Yun, Z. Hongwei, Yu Jie
A Double-horizontal-array (DHA) passive ranging algorithm is proposed. Based on the waveguide invariant theory, the interference fringes can be extracted by applying the Radon transform to the interference structure obtained by spectral analysis of the tracking beamform output of each array. The passive ranging accuracy can be improved by adopting the interference striations in the two interference structures whose slopes are identical combined with the traditional passive ranging algorithm. Simulation and analysis of positioning accuracy indicate that the improved passive ranging algorithms are simple and can greatly improve the ranging accuracy. The improved passive ranging algorithms can estimate the target range without detailed prior knowledge of the marine environment, which provides guidelines for towed line arrays when used for passive ranging.
{"title":"Improved passive ranging algorithm based on the waveguide invariant theory","authors":"Yu Yun, Z. Hongwei, Yu Jie","doi":"10.1109/COA.2016.7535681","DOIUrl":"https://doi.org/10.1109/COA.2016.7535681","url":null,"abstract":"A Double-horizontal-array (DHA) passive ranging algorithm is proposed. Based on the waveguide invariant theory, the interference fringes can be extracted by applying the Radon transform to the interference structure obtained by spectral analysis of the tracking beamform output of each array. The passive ranging accuracy can be improved by adopting the interference striations in the two interference structures whose slopes are identical combined with the traditional passive ranging algorithm. Simulation and analysis of positioning accuracy indicate that the improved passive ranging algorithms are simple and can greatly improve the ranging accuracy. The improved passive ranging algorithms can estimate the target range without detailed prior knowledge of the marine environment, which provides guidelines for towed line arrays when used for passive ranging.","PeriodicalId":155481,"journal":{"name":"2016 IEEE/OES China Ocean Acoustics (COA)","volume":"135 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122494286","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1900-01-01DOI: 10.1109/COA.2016.7535673
Wen Tao, Xu Feng, Yang Juan, An Xu-dong, Wem Tao, Wang Mengbin
An identification method based on multi-aspect target scattering characteristics when the transmitting and receiving transducer are separated is proposed in this essay. Target strengths of each target at different bistatic angles are calculated, and form a combined vector. Then the first-order and second-order moment features are abstracted. Pool experiment of three targets has been conducted, and the features proposed by this easy are abstracted. The support vector machine classifier is employed to identify the target. The identification rate is up to 100% in the anechoic tank environment.
{"title":"An identification method based on multi-aspect target scattering characteristics","authors":"Wen Tao, Xu Feng, Yang Juan, An Xu-dong, Wem Tao, Wang Mengbin","doi":"10.1109/COA.2016.7535673","DOIUrl":"https://doi.org/10.1109/COA.2016.7535673","url":null,"abstract":"An identification method based on multi-aspect target scattering characteristics when the transmitting and receiving transducer are separated is proposed in this essay. Target strengths of each target at different bistatic angles are calculated, and form a combined vector. Then the first-order and second-order moment features are abstracted. Pool experiment of three targets has been conducted, and the features proposed by this easy are abstracted. The support vector machine classifier is employed to identify the target. The identification rate is up to 100% in the anechoic tank environment.","PeriodicalId":155481,"journal":{"name":"2016 IEEE/OES China Ocean Acoustics (COA)","volume":"98 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122609765","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1900-01-01DOI: 10.1109/COA.2016.7535746
Wu Yanqun, Ana Bela dos Santos, P. Felisberto, S. Jesus
Distant ship noise has been utilized for geoacoustic inversion and ocean monitoring for many years. In a shallow water experiment, Makai 2005, a 4-element acoustic vector sensor array was deployed at the stern of the research vessel R/V Kilo Moana. The recorded engine noise of R/V Kilo Moana during its dynamic positioning was analyzed by the DEMON (Detection of Envelope Modulation on Noise) method. The strongest modulation frequency band of the ship noise was found by a group of band-pass filters for further data processing. Multipath arrivals in the vertical particle velocity have higher signal-to-noise ratios than those in the horizontal particle velocities because of steep arrival directions. By exploiting this advantage, the cross-correlation of broadband ship noise between the pressure and the vertical particle velocity can be used for multipath information exploration. Since ship noise is often characterized as continuous broadband noise plus strong tonal noise, the cross-correlation of tonal noise would dominate that of broadband noise, and consequently cover the multipath arrival pattern. Therefore, spectral weighting functions are applied in order to reduce the noise contamination and ensure sharp multipath peaks in the cross-correlation. For engine noise emitted by the dynamically positioned ship, a short correlation time of 0.4s was used in order to keep the time delay fluctuation details of multipath arrivals. Clear multiple arrivals are seen in the cross-correlation of different arrivals, and verified by the ray tracing program TRACEO. The results demonstrate the potential of only one acoustic vector sensor in applications of source localization and geoacoustic inversion.
远洋船舶噪声用于地球声反演和海洋监测已有多年历史。在马凯2005年的一次浅水实验中，在科考船R/V基洛莫阿纳的尾部部署了一个4元声矢量传感器阵列。采用噪声包络调制检测(Detection of Envelope Modulation on noise, DEMON)方法对R/V“基洛莫阿纳”动态定位过程中记录的发动机噪声进行了分析。通过一组带通滤波器找出船舶噪声的最强调制频带，进行进一步的数据处理。由于到达方向陡峭，垂直粒子速度下的多径到达比水平粒子速度下的多径到达具有更高的信噪比。利用这一优势，利用宽频船舶噪声在压力和垂直粒子速度之间的相互关系进行多径信息探测。由于船舶噪声通常表现为连续宽带噪声加强调性噪声，因此调性噪声的相互关系将压倒宽带噪声的相互关系，从而覆盖多径到达模式。因此，为了减少噪声污染，保证互相关中的多径峰清晰，采用了谱加权函数。对于动态定位船舶发出的发动机噪声，为了保持多径到达时的时延波动细节，采用了0.4s的短相关时间。在不同到达点的相互关联中可以看到清晰的多个到达点，并通过光线追踪程序TRACEO进行验证。结果表明，单一声矢量传感器在声源定位和地球声反演中的应用潜力巨大。
{"title":"Close range ship noise cross correlations with a vector sensor in view of geoacoustic inversion","authors":"Wu Yanqun, Ana Bela dos Santos, P. Felisberto, S. Jesus","doi":"10.1109/COA.2016.7535746","DOIUrl":"https://doi.org/10.1109/COA.2016.7535746","url":null,"abstract":"Distant ship noise has been utilized for geoacoustic inversion and ocean monitoring for many years. In a shallow water experiment, Makai 2005, a 4-element acoustic vector sensor array was deployed at the stern of the research vessel R/V Kilo Moana. The recorded engine noise of R/V Kilo Moana during its dynamic positioning was analyzed by the DEMON (Detection of Envelope Modulation on Noise) method. The strongest modulation frequency band of the ship noise was found by a group of band-pass filters for further data processing. Multipath arrivals in the vertical particle velocity have higher signal-to-noise ratios than those in the horizontal particle velocities because of steep arrival directions. By exploiting this advantage, the cross-correlation of broadband ship noise between the pressure and the vertical particle velocity can be used for multipath information exploration. Since ship noise is often characterized as continuous broadband noise plus strong tonal noise, the cross-correlation of tonal noise would dominate that of broadband noise, and consequently cover the multipath arrival pattern. Therefore, spectral weighting functions are applied in order to reduce the noise contamination and ensure sharp multipath peaks in the cross-correlation. For engine noise emitted by the dynamically positioned ship, a short correlation time of 0.4s was used in order to keep the time delay fluctuation details of multipath arrivals. Clear multiple arrivals are seen in the cross-correlation of different arrivals, and verified by the ray tracing program TRACEO. The results demonstrate the potential of only one acoustic vector sensor in applications of source localization and geoacoustic inversion.","PeriodicalId":155481,"journal":{"name":"2016 IEEE/OES China Ocean Acoustics (COA)","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117087763","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1900-01-01DOI: 10.1109/COA.2016.7535697
Qing Xin, Nie Donghu, Qiao Gang, Tan Jiansheng
Recognition of material for underwater small targets is an extremely difficult task for the traditional CW and LFM signal. In order to distinguish different material types of underwater small targets with the same size and geometry, a series of broadband, transient-like bio-inspired dolphin sonar signals (clicks) are used as the transmitting waveform. In the joint time-frequency space, Reduced Interference Distribution (RID) is used to analyze the echoes, and then the RID-SV feature is extracted by singular value decomposition (SVD). The Support Vector Machines (SVM) are used to classify echoes. In order to verify the efficiency of the bio-inspired click signal for distinguishing materials, an anechoic pool experiment was conducted. In this experiment, three bio-inspired dolphin signals are generated by two linear frequency modulation component covering different frequency band in 40-80 kHz. These three signals are used to detect and recognize three 10 cm diameter solid spherical targets with different materials (copper, aluminum, stainless). Experimental results show that these spherical targets can be classified according to the bio-inspired dolphin click echo; Results also suggest that the classification of underwater small targets made form different materials can be improved by altering energy distribution of the bio-inspired signal in the frequency space.
{"title":"Classification for underwater small targets with different materials using bio-inspired Dolphin click","authors":"Qing Xin, Nie Donghu, Qiao Gang, Tan Jiansheng","doi":"10.1109/COA.2016.7535697","DOIUrl":"https://doi.org/10.1109/COA.2016.7535697","url":null,"abstract":"Recognition of material for underwater small targets is an extremely difficult task for the traditional CW and LFM signal. In order to distinguish different material types of underwater small targets with the same size and geometry, a series of broadband, transient-like bio-inspired dolphin sonar signals (clicks) are used as the transmitting waveform. In the joint time-frequency space, Reduced Interference Distribution (RID) is used to analyze the echoes, and then the RID-SV feature is extracted by singular value decomposition (SVD). The Support Vector Machines (SVM) are used to classify echoes. In order to verify the efficiency of the bio-inspired click signal for distinguishing materials, an anechoic pool experiment was conducted. In this experiment, three bio-inspired dolphin signals are generated by two linear frequency modulation component covering different frequency band in 40-80 kHz. These three signals are used to detect and recognize three 10 cm diameter solid spherical targets with different materials (copper, aluminum, stainless). Experimental results show that these spherical targets can be classified according to the bio-inspired dolphin click echo; Results also suggest that the classification of underwater small targets made form different materials can be improved by altering energy distribution of the bio-inspired signal in the frequency space.","PeriodicalId":155481,"journal":{"name":"2016 IEEE/OES China Ocean Acoustics (COA)","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117170650","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1900-01-01DOI: 10.1109/COA.2016.7535809
Zhao An-bang, Zhao Zhishan, Hui Juan, N. Fang
A simulation method using the acoustic software SYSNOISE to study far-field acoustic performance in different angles of a planar phased array in broadside dome is performed. The planar array is installed parallel to the vessel centerline. The cases in which the acoustic window is parallel to the planar array and at an angle of 8 degrees are separately calculated. The simulation results show that the impact of the acoustic window to the far-field beams when the acoustic window is parallel to the array is smaller. When they are at an angle of 8 degrees, the impact of the acoustic window on the side lobes is more obvious than it on the main lobe. The cases when the acoustic window is fully transmissive and when it is with a titanium film are calculated. The titanium film introduces an obvious insertion loss, and the insertion loss of the side lobes is significantly larger than that in the case of the main lobe. The results have a practical significance to sonar installations in broadside domes.
{"title":"Simulation of the effect of acoustic window to the planar array at different angles","authors":"Zhao An-bang, Zhao Zhishan, Hui Juan, N. Fang","doi":"10.1109/COA.2016.7535809","DOIUrl":"https://doi.org/10.1109/COA.2016.7535809","url":null,"abstract":"A simulation method using the acoustic software SYSNOISE to study far-field acoustic performance in different angles of a planar phased array in broadside dome is performed. The planar array is installed parallel to the vessel centerline. The cases in which the acoustic window is parallel to the planar array and at an angle of 8 degrees are separately calculated. The simulation results show that the impact of the acoustic window to the far-field beams when the acoustic window is parallel to the array is smaller. When they are at an angle of 8 degrees, the impact of the acoustic window on the side lobes is more obvious than it on the main lobe. The cases when the acoustic window is fully transmissive and when it is with a titanium film are calculated. The titanium film introduces an obvious insertion loss, and the insertion loss of the side lobes is significantly larger than that in the case of the main lobe. The results have a practical significance to sonar installations in broadside domes.","PeriodicalId":155481,"journal":{"name":"2016 IEEE/OES China Ocean Acoustics (COA)","volume":"89 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121581473","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1900-01-01DOI: 10.1109/COA.2016.7535827
Yang Chunmei, Lyu Liangang, Q. Fangli, Luo Wenyu
An exact analytical solution for three-dimensional sound propagation excited by a point source in a penetrable wedge-shaped ocean is first presented in this paper. Although Deane and Buckingham have proposed an analytical solution for the acoustic field in the water of a penetrable wedge (Journal of the Acoustical Society of America, 1993, 93(3): 1319~1328), the analytical solution is not complete. It is only applicable for sea water not for the seabed, hereafter called bottom. This paper presents an analytical field solution which not only applies to sea water but also the bottom. The analytical solution is obtained by using the method of source images. For the acoustic field in the water of a penetrable wedge, only acoustic reflection needs to be considered. All the source images on a circle centered on the wedge apex need to be involved in the computation. However, for the acoustic field at the bottom of a penetrable wedge, both acoustic reflection and acoustic refraction need to be considered. Only the source images above the bottom on a semicircle need to be involved in the computation. The analytical solution in the whole sea area can be obtained based on the plane wave reflection and refraction principles. In addition, a three-dimensional numerical model based on the wavenumber integration method is also presented and implemented in an unconditionally stable direct-global-matrix coupled-mode method. Afterwards, the three-dimensional numerical model is applied to sound propagation excited by a point source in a benchmark wedge waveguide. The numerical solutions from the three-dimensional model agree well with the analytical solutions in the benchmark wedge waveguide. Consequently, the present three-dimensional model is validated through the analytical solutions to the benchmark wedge problem.
本文首次给出了可穿透楔形海洋中由点源激发的三维声传播的精确解析解。虽然Deane和Buckingham已经提出了可穿透楔体水中声场的解析解(Journal of acoustic Society of America, 1993,93(3): 1319~1328)，但解析解并不完整。它只适用于海水，不适用于海床，以下称为底部。本文提出了一种既适用于海水也适用于海底的解析场解。采用源图像法得到了解析解。对于可穿透楔体的水中声场，只需考虑声反射。以楔形顶点为中心的圆上的所有源图像都需要参与计算。然而，对于可穿透楔形底部的声场，需要同时考虑声反射和声折射。只有位于半圆底部上方的源图像需要参与计算。基于平面波反射和折射原理，可以得到整个海域的解析解。此外，还提出了基于波数积分法的三维数值模型，并以无条件稳定的直接全局矩阵耦合模式方法实现。然后，将三维数值模型应用于基准楔形波导中点源激励下的声音传播。三维模型的数值解与基准楔形波导的解析解吻合较好。因此，通过基准楔问题的解析解，验证了该三维模型的有效性。
{"title":"Three-dimensional analytical solution and numerical solution in a penetrable wedge-shaped waveguide","authors":"Yang Chunmei, Lyu Liangang, Q. Fangli, Luo Wenyu","doi":"10.1109/COA.2016.7535827","DOIUrl":"https://doi.org/10.1109/COA.2016.7535827","url":null,"abstract":"An exact analytical solution for three-dimensional sound propagation excited by a point source in a penetrable wedge-shaped ocean is first presented in this paper. Although Deane and Buckingham have proposed an analytical solution for the acoustic field in the water of a penetrable wedge (Journal of the Acoustical Society of America, 1993, 93(3): 1319~1328), the analytical solution is not complete. It is only applicable for sea water not for the seabed, hereafter called bottom. This paper presents an analytical field solution which not only applies to sea water but also the bottom. The analytical solution is obtained by using the method of source images. For the acoustic field in the water of a penetrable wedge, only acoustic reflection needs to be considered. All the source images on a circle centered on the wedge apex need to be involved in the computation. However, for the acoustic field at the bottom of a penetrable wedge, both acoustic reflection and acoustic refraction need to be considered. Only the source images above the bottom on a semicircle need to be involved in the computation. The analytical solution in the whole sea area can be obtained based on the plane wave reflection and refraction principles. In addition, a three-dimensional numerical model based on the wavenumber integration method is also presented and implemented in an unconditionally stable direct-global-matrix coupled-mode method. Afterwards, the three-dimensional numerical model is applied to sound propagation excited by a point source in a benchmark wedge waveguide. The numerical solutions from the three-dimensional model agree well with the analytical solutions in the benchmark wedge waveguide. Consequently, the present three-dimensional model is validated through the analytical solutions to the benchmark wedge problem.","PeriodicalId":155481,"journal":{"name":"2016 IEEE/OES China Ocean Acoustics (COA)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126146193","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1900-01-01DOI: 10.1109/COA.2016.7535814
B. Katsnelson, Yun Ren
On the base of experimental data of ASIAEX 01 and the corresponding theoretical analysis it is shown existence of predominating frequencies in spectrum of the sound intensity fluctuations in the presence of nonlinear internal waves moving along acoustic track. Both the speed of internal waves and scales of interference beating of waveguide modes determine mentioned frequencies.
{"title":"Sound intensity fluctuations due to mode coupling on moving internal waves","authors":"B. Katsnelson, Yun Ren","doi":"10.1109/COA.2016.7535814","DOIUrl":"https://doi.org/10.1109/COA.2016.7535814","url":null,"abstract":"On the base of experimental data of ASIAEX 01 and the corresponding theoretical analysis it is shown existence of predominating frequencies in spectrum of the sound intensity fluctuations in the presence of nonlinear internal waves moving along acoustic track. Both the speed of internal waves and scales of interference beating of waveguide modes determine mentioned frequencies.","PeriodicalId":155481,"journal":{"name":"2016 IEEE/OES China Ocean Acoustics (COA)","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130008980","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1900-01-01DOI: 10.1109/COA.2016.7535772
W. Duan, Y. R. Zheng, Dajun Sun, Youwen Zhang
In this paper, we propose a low complexity iterative detection scheme for the uncoded zero padding (ZP) single carrier (SC) transmission in Multiple-input Multiple-output (MIMO) underwater acoustic (UWA) channels. Due to the long multipath in UWA channels, ZP SC-FDE has to use large block size to achieve low computational complexity and high data efficiency. But, the higher bandwidth efficiency results in more sever channel estimation error and performance degradation. To enhance the performance of the ZP SC systems with high data efficiency, we design a soft-decision block iterative frequency-domain equalization (BI-FDE) combined with iterative channel estimation. With increasing reliability as the the iteration proceeds, the soft decision symbols obtained at the previous iteration are used to re-estimate the channel, thus improving the overall system performance. Since both the feedfoward and feedback filters are designed in frequency domain without the aid of channel coding, the proposed SD BI-FDE scheme is affordable for real-time implementation. The performance enhancement of the proposed iterative receiver has been verified through a pool test.
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