Pub Date : 2016-08-08DOI: 10.1109/COA.2016.7535626
Zhao Tianji, Cheng Hongjuan, Z. Hu, Li Zhi, T. Le
Addressing the subject of a suspended co-oscillating vector hydrophone application platform, a new sound wave receiving theory model of underwater particle velocity pickup sensor was established. Based on the study of the inner sound field of an elastic sphere vibrating freely under the action of sound waves in theory, the influence of material and geometry parameters on the frequency response of particle velocity has been analyzed. According to the results of parameter optimization and taking into account engineering needs, two samples of one-dimensional particle velocity pickup sensor have been designed and tested. By comparing the results of sensitivity tested in a calibration device, the general rules of theoretical analysis have been verified. The theory and experiments confirmed the feasibility of particle velocity pickup sensors in engineering applications.
{"title":"Design of underwater particle velocity pickup sensor","authors":"Zhao Tianji, Cheng Hongjuan, Z. Hu, Li Zhi, T. Le","doi":"10.1109/COA.2016.7535626","DOIUrl":"https://doi.org/10.1109/COA.2016.7535626","url":null,"abstract":"Addressing the subject of a suspended co-oscillating vector hydrophone application platform, a new sound wave receiving theory model of underwater particle velocity pickup sensor was established. Based on the study of the inner sound field of an elastic sphere vibrating freely under the action of sound waves in theory, the influence of material and geometry parameters on the frequency response of particle velocity has been analyzed. According to the results of parameter optimization and taking into account engineering needs, two samples of one-dimensional particle velocity pickup sensor have been designed and tested. By comparing the results of sensitivity tested in a calibration device, the general rules of theoretical analysis have been verified. The theory and experiments confirmed the feasibility of particle velocity pickup sensors in engineering applications.","PeriodicalId":155481,"journal":{"name":"2016 IEEE/OES China Ocean Acoustics (COA)","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114635173","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 : 2016-08-08DOI: 10.1109/COA.2016.7535808
Sun Mei, S. Zhou, Fenghua Li
Vector sensors have attracted extensive interest for their abilities to measure the scalar acoustic pressure field and particle velocity at a single location in space. During a deep-water experiment held in the South China Sea in 2014, a vector sensor placed at the depth of 3146 m received the experimental signals launched from a towed transducer at 140 m depth. In the direct-arrival zone of the sound field generated by the towed source, the propagation properties of the vector sound field are studied based on the ray theory. It is shown that both the energies of the horizontal particle velocity and the vertical particle velocity are closely related to the grazing angle, which varies greatly with the horizontal distance between the source and the receiver. Then a source-range-estimation method is proposed based on the energy difference between the horizontal particle velocity and the vertical particle velocity. The proposed method is tested by experimental data.
{"title":"Analysis of vector sound field in the direct-arrival zone in deep water","authors":"Sun Mei, S. Zhou, Fenghua Li","doi":"10.1109/COA.2016.7535808","DOIUrl":"https://doi.org/10.1109/COA.2016.7535808","url":null,"abstract":"Vector sensors have attracted extensive interest for their abilities to measure the scalar acoustic pressure field and particle velocity at a single location in space. During a deep-water experiment held in the South China Sea in 2014, a vector sensor placed at the depth of 3146 m received the experimental signals launched from a towed transducer at 140 m depth. In the direct-arrival zone of the sound field generated by the towed source, the propagation properties of the vector sound field are studied based on the ray theory. It is shown that both the energies of the horizontal particle velocity and the vertical particle velocity are closely related to the grazing angle, which varies greatly with the horizontal distance between the source and the receiver. Then a source-range-estimation method is proposed based on the energy difference between the horizontal particle velocity and the vertical particle velocity. The proposed method is tested by experimental data.","PeriodicalId":155481,"journal":{"name":"2016 IEEE/OES China Ocean Acoustics (COA)","volume":"68 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116037862","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 : 2016-08-08DOI: 10.1109/COA.2016.7535677
Bo You, Zhiming Cai
The change of the probability distribution function (PDF), or related parameters, is one of the basic changes of the statistical characteristics when the sonar target signal emerges or disappears. The Page Test can detect transients effectively based on this principle. It is more difficult for the Page Test to detect passive sonar signals because of unknown signal parameters. Generally based on Newman-Pearson criterion, given the certain transient length, the Page Test works well with these parameters which are calculated with the detection performance model, such as the threshold and the bias. When the real signal length mismatches the designed one, those parameters are no longer accurate and performance of the detector decreases remarkably. In this paper the time-varying-threshold Page Test (VPT) insensitive to the signal length is researched. The theoretical detection probability (Pd) model of the VPT is more complicated than the routine Page Test because the threshold changes with the length of continuous nonzero detection results. The methods to calculate the normal and latent Pd of nonzero initial state are deduced in this paper. The theoretical analyses and the simulated results of Pd are compared between the VPT and the routine Page Test (PT) on two cases of matched transient signal length and mismatched one. The sea trial data of certain bearing channel after beam-forming are used to test these two methods. The results indicate that the former is better than the mismatched PT, but inferior to the matched one. In fact the signal length matched detection can not be realized because the signal length can not be obtained.
{"title":"Research on performance of the Page Test independent of unknown signal length","authors":"Bo You, Zhiming Cai","doi":"10.1109/COA.2016.7535677","DOIUrl":"https://doi.org/10.1109/COA.2016.7535677","url":null,"abstract":"The change of the probability distribution function (PDF), or related parameters, is one of the basic changes of the statistical characteristics when the sonar target signal emerges or disappears. The Page Test can detect transients effectively based on this principle. It is more difficult for the Page Test to detect passive sonar signals because of unknown signal parameters. Generally based on Newman-Pearson criterion, given the certain transient length, the Page Test works well with these parameters which are calculated with the detection performance model, such as the threshold and the bias. When the real signal length mismatches the designed one, those parameters are no longer accurate and performance of the detector decreases remarkably. In this paper the time-varying-threshold Page Test (VPT) insensitive to the signal length is researched. The theoretical detection probability (Pd) model of the VPT is more complicated than the routine Page Test because the threshold changes with the length of continuous nonzero detection results. The methods to calculate the normal and latent Pd of nonzero initial state are deduced in this paper. The theoretical analyses and the simulated results of Pd are compared between the VPT and the routine Page Test (PT) on two cases of matched transient signal length and mismatched one. The sea trial data of certain bearing channel after beam-forming are used to test these two methods. The results indicate that the former is better than the mismatched PT, but inferior to the matched one. In fact the signal length matched detection can not be realized because the signal length can not be obtained.","PeriodicalId":155481,"journal":{"name":"2016 IEEE/OES China Ocean Acoustics (COA)","volume":"38 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127632746","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 : 2016-08-08DOI: 10.1109/COA.2016.7535682
Chen Yu, Meng Zhou, Ma Shuqing, Bao Changchun
The pressure and horizontal velocity signals of a vector hydrophone are combined in passive range localization processing. The target in the ocean is moving at a constant speed and the track does not cross the receiver point. Range localization is achieved through four main steps. Firstly, the received pressure and particle velocity are processed together to restrain the isotropic noise. Second, the signals received at different time are cross-correlated and processed to obtain the interference pattern of the intensity field. Third, the radial velocity of the moving source can be extracted from the interference and the following obtained: the best match of the constant speed of the target and the range; and the time of the Closest Point of Approach (CPA). Finally, the range localization is achieved according to the motion equation. In comparison with the pressure sensor, the vector hydrophone has a higher signal to noise ratio (SNR) for its 4-6dB spatial gain in the isotropic noise field. Hence, the performance of range passive localization for the moving source is improved by using a vector hydrophone.
{"title":"Range passive localization of the moving source with a single vector hydrophone","authors":"Chen Yu, Meng Zhou, Ma Shuqing, Bao Changchun","doi":"10.1109/COA.2016.7535682","DOIUrl":"https://doi.org/10.1109/COA.2016.7535682","url":null,"abstract":"The pressure and horizontal velocity signals of a vector hydrophone are combined in passive range localization processing. The target in the ocean is moving at a constant speed and the track does not cross the receiver point. Range localization is achieved through four main steps. Firstly, the received pressure and particle velocity are processed together to restrain the isotropic noise. Second, the signals received at different time are cross-correlated and processed to obtain the interference pattern of the intensity field. Third, the radial velocity of the moving source can be extracted from the interference and the following obtained: the best match of the constant speed of the target and the range; and the time of the Closest Point of Approach (CPA). Finally, the range localization is achieved according to the motion equation. In comparison with the pressure sensor, the vector hydrophone has a higher signal to noise ratio (SNR) for its 4-6dB spatial gain in the isotropic noise field. Hence, the performance of range passive localization for the moving source is improved by using a vector hydrophone.","PeriodicalId":155481,"journal":{"name":"2016 IEEE/OES China Ocean Acoustics (COA)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133066405","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 : 2016-08-08DOI: 10.1109/COA.2016.7535795
Xue Han, S. Piao, Shizhao Zhang
In order to suppress ocean noise, this paper proposes a noise normalization method based on polarization filtering of the fourth-order mixed cumulant slice. According to the difference of signals and noise in polarization, the polarization parameters of underwater signals are calculated, and a polarization filter is constructed according to the characteristics of polarization statistics. Simulation and experimental results show that the proposed method provides a new approach for noise normalization techniques.
{"title":"Noise normalization based on the polarization filtering of fourth-order mixed cumulant slice","authors":"Xue Han, S. Piao, Shizhao Zhang","doi":"10.1109/COA.2016.7535795","DOIUrl":"https://doi.org/10.1109/COA.2016.7535795","url":null,"abstract":"In order to suppress ocean noise, this paper proposes a noise normalization method based on polarization filtering of the fourth-order mixed cumulant slice. According to the difference of signals and noise in polarization, the polarization parameters of underwater signals are calculated, and a polarization filter is constructed according to the characteristics of polarization statistics. Simulation and experimental results show that the proposed method provides a new approach for noise normalization techniques.","PeriodicalId":155481,"journal":{"name":"2016 IEEE/OES China Ocean Acoustics (COA)","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132616222","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}
Growing interest for underwater acoustics leads to take-up underwater applications in a commercial aspect, not only viewing it in a research aspect. This expects a good signal reception at the user end point. The received signal inherently acknowledges the high quality communication system. On the whole practicing efficient signal processing techniques for the end to end process with acceptable tradeoffs is the need of the hour. Processing the received signal is focused here which is a challenging task. Noise reduction is important in underwater acoustic signal processing. However, minimizing error does not guarantee a smooth filtering result. Using wavelet soft thresholding (STH) and time scale filter (TSF) techniques, noise reduction for the underwater signals degraded by ambient noise sources is analysed. In this work, typical noises like snapping shrimp sound and rainfall sound which can interfere with sonar and underwater communication signal causing severe degradation to the received signal is handled. Based on the typical evaluation metrics, results were compared.
{"title":"Noise reduction in underwater acoustic signals for tropical and subtropical coastal waters","authors":"Sumithra Ganapathi, Suresh Kumar, Meganathan Deivasigamani","doi":"10.1109/COA.2016.7535678","DOIUrl":"https://doi.org/10.1109/COA.2016.7535678","url":null,"abstract":"Growing interest for underwater acoustics leads to take-up underwater applications in a commercial aspect, not only viewing it in a research aspect. This expects a good signal reception at the user end point. The received signal inherently acknowledges the high quality communication system. On the whole practicing efficient signal processing techniques for the end to end process with acceptable tradeoffs is the need of the hour. Processing the received signal is focused here which is a challenging task. Noise reduction is important in underwater acoustic signal processing. However, minimizing error does not guarantee a smooth filtering result. Using wavelet soft thresholding (STH) and time scale filter (TSF) techniques, noise reduction for the underwater signals degraded by ambient noise sources is analysed. In this work, typical noises like snapping shrimp sound and rainfall sound which can interfere with sonar and underwater communication signal causing severe degradation to the received signal is handled. Based on the typical evaluation metrics, results were compared.","PeriodicalId":155481,"journal":{"name":"2016 IEEE/OES China Ocean Acoustics (COA)","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133730285","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 : 2016-08-08DOI: 10.1109/COA.2016.7535773
Ying Jiang, Zhiguo Yang, Lü Lian-Gang
Marine mammals are always swimming in a random trajectory, which makes it challenging to monitor and locate marine mammals with passive acoustic methods. They emit acoustics signals for hunting, localization and so on. The spectrum of the signals spread from several kilo hertz to more than two hundred kilo hertz. In this study, a portable towed array system, Low Power data Acquired System-Double channel (LoPAS-D) is developed in order to detect and locate marine mammals with passive acoustics methods. The LoPAS-D system consists of a towed receiving array and a data acquisition module. The towed array includes two broadband hydrophones spaced at 50 cm. The data acquisition module consists of high-speed data acquisition and storage modules. It is capable of sampling at 512 kHz with 16-bit resolution. Synchronized sampling can be realized for multiple LoPAS-D systems in several hours after initialization, which makes it possible to locate marine mammals with two LoPAS-D systems. Then two LoPAS-D systems used for localization of marine mammal after synchronization is discussed. The time difference of arrival (TDOA) and direction of arrival (DOA) methods are estimated individually. Localization is realized according to triangulation. Monte-Carlo simulation is used to evaluate the localization accuracy. The results show that the relative range error is less than six percent at a distance of 200 m.
{"title":"The localization of marine mammal with LoPAS-D system","authors":"Ying Jiang, Zhiguo Yang, Lü Lian-Gang","doi":"10.1109/COA.2016.7535773","DOIUrl":"https://doi.org/10.1109/COA.2016.7535773","url":null,"abstract":"Marine mammals are always swimming in a random trajectory, which makes it challenging to monitor and locate marine mammals with passive acoustic methods. They emit acoustics signals for hunting, localization and so on. The spectrum of the signals spread from several kilo hertz to more than two hundred kilo hertz. In this study, a portable towed array system, Low Power data Acquired System-Double channel (LoPAS-D) is developed in order to detect and locate marine mammals with passive acoustics methods. The LoPAS-D system consists of a towed receiving array and a data acquisition module. The towed array includes two broadband hydrophones spaced at 50 cm. The data acquisition module consists of high-speed data acquisition and storage modules. It is capable of sampling at 512 kHz with 16-bit resolution. Synchronized sampling can be realized for multiple LoPAS-D systems in several hours after initialization, which makes it possible to locate marine mammals with two LoPAS-D systems. Then two LoPAS-D systems used for localization of marine mammal after synchronization is discussed. The time difference of arrival (TDOA) and direction of arrival (DOA) methods are estimated individually. Localization is realized according to triangulation. Monte-Carlo simulation is used to evaluate the localization accuracy. The results show that the relative range error is less than six percent at a distance of 200 m.","PeriodicalId":155481,"journal":{"name":"2016 IEEE/OES China Ocean Acoustics (COA)","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124044550","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 : 2016-08-08DOI: 10.1109/COA.2016.7535823
Shashidhar Siddagangaiah, Ya'an Li
In this paper, we intend to quantify the dynamical complexity ofunderwater acoustical signals (UAS) based on multiscale sample entropy (MSE). MSE is calculated for three types of UAS which were measured in the South China Sea: ambient noise, and near and distant experimental vessels moving at constant velocity. [The analysis of real UAS exhibit high entropy values were assigned for ambient noise and low values for target signals.][NOTE: it is not clear what this means] This result suggests that the ambient noise is dynamically more complex than the target signals within the ambient noise. [It is also shown that dynamical behavior of far target approaching ambient noise behavior due to the weak ship noise.][NOTE: it is not clear what this means] This affirms that ship noise is regular and, when present in ambient noise, can be detected by the change in their dynamical complexity.
{"title":"Reduction in the dynamical complexity of the ocean ambient noise in the presence of target","authors":"Shashidhar Siddagangaiah, Ya'an Li","doi":"10.1109/COA.2016.7535823","DOIUrl":"https://doi.org/10.1109/COA.2016.7535823","url":null,"abstract":"In this paper, we intend to quantify the dynamical complexity ofunderwater acoustical signals (UAS) based on multiscale sample entropy (MSE). MSE is calculated for three types of UAS which were measured in the South China Sea: ambient noise, and near and distant experimental vessels moving at constant velocity. [The analysis of real UAS exhibit high entropy values were assigned for ambient noise and low values for target signals.][NOTE: it is not clear what this means] This result suggests that the ambient noise is dynamically more complex than the target signals within the ambient noise. [It is also shown that dynamical behavior of far target approaching ambient noise behavior due to the weak ship noise.][NOTE: it is not clear what this means] This affirms that ship noise is regular and, when present in ambient noise, can be detected by the change in their dynamical complexity.","PeriodicalId":155481,"journal":{"name":"2016 IEEE/OES China Ocean Acoustics (COA)","volume":"211 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132272558","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 : 2016-08-08DOI: 10.1109/COA.2016.7535724
Wang Yan, Li Qing, Fu Jin, Liang Guolong
For locating underwater targets moving in a large range, long baseline (LBL) synchronous acoustic positioning is always employed. Aiming at suppressing range ambiguity and improving performance of the LBL system, a novel range ambiguity resolution technique is proposed which is based on parameter fusion and optimization (RAR-PFO). From the perspective of parameter estimation, the basic idea was to build an optimization model with distance and direction parameters under maximum likelihood criterion. Furthermore, the nonlinear multimodal optimization problem was solved through differential evolution (DE). The constraint function limits the area where the target is located and suppresses premature convergence of DE. Performance of the proposed approach is evaluated using simulations, and compared with some widely applied methods and the Cramer-Rao bound. Simulation results demonstrated the effectiveness and robustness of the proposed method.
{"title":"Resolving range ambiguity in long baseline synchronous acoustic positioning","authors":"Wang Yan, Li Qing, Fu Jin, Liang Guolong","doi":"10.1109/COA.2016.7535724","DOIUrl":"https://doi.org/10.1109/COA.2016.7535724","url":null,"abstract":"For locating underwater targets moving in a large range, long baseline (LBL) synchronous acoustic positioning is always employed. Aiming at suppressing range ambiguity and improving performance of the LBL system, a novel range ambiguity resolution technique is proposed which is based on parameter fusion and optimization (RAR-PFO). From the perspective of parameter estimation, the basic idea was to build an optimization model with distance and direction parameters under maximum likelihood criterion. Furthermore, the nonlinear multimodal optimization problem was solved through differential evolution (DE). The constraint function limits the area where the target is located and suppresses premature convergence of DE. Performance of the proposed approach is evaluated using simulations, and compared with some widely applied methods and the Cramer-Rao bound. Simulation results demonstrated the effectiveness and robustness of the proposed method.","PeriodicalId":155481,"journal":{"name":"2016 IEEE/OES China Ocean Acoustics (COA)","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130813261","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 : 2016-08-08DOI: 10.1109/COA.2016.7535753
Xiufen Qiu, Heping Shen, Chunyan Sun, Yile Liu
Distortion of array shape must be taken into account in large aperture optical towed array signal processing. The amount of distortion of an array shape will influence the performance of subsequent signal processing. The null-forming technique is a strong interference suppression method widely used in towed linear array detection systems, and plays an important role in ship interference cancellation and the detection of weak targets. This paper researches the effect on null-forming performance when a towed linear array is distorted into an arc array. We also compare straight and arc arrays by analysing the results of simulating arc arrays at different angles. The simulation results indicate that, as the main lobe of a target's beam becomes wider, the accuracy of DOA descends and the effect of strong interference suppression gets worse. In addition, the detection of weak targets is severely affected if a linear array is still processed as straight when the y-coordinate of the array deviates from its horizontal axis by more than 4 meters.
{"title":"Research on influence of distortion of large aperture optical towed linear array shape on null-forming algorithm","authors":"Xiufen Qiu, Heping Shen, Chunyan Sun, Yile Liu","doi":"10.1109/COA.2016.7535753","DOIUrl":"https://doi.org/10.1109/COA.2016.7535753","url":null,"abstract":"Distortion of array shape must be taken into account in large aperture optical towed array signal processing. The amount of distortion of an array shape will influence the performance of subsequent signal processing. The null-forming technique is a strong interference suppression method widely used in towed linear array detection systems, and plays an important role in ship interference cancellation and the detection of weak targets. This paper researches the effect on null-forming performance when a towed linear array is distorted into an arc array. We also compare straight and arc arrays by analysing the results of simulating arc arrays at different angles. The simulation results indicate that, as the main lobe of a target's beam becomes wider, the accuracy of DOA descends and the effect of strong interference suppression gets worse. In addition, the detection of weak targets is severely affected if a linear array is still processed as straight when the y-coordinate of the array deviates from its horizontal axis by more than 4 meters.","PeriodicalId":155481,"journal":{"name":"2016 IEEE/OES China Ocean Acoustics (COA)","volume":"45 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115239592","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}
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