Shallow water acoustic network (SWAN) communication has been an area of active research over the recent years. Due to the wave motion, the multipath components undergo time-varying propagation delays that result in signal attenuation and phase fluctuations. Although the adaptive decision feedback equalization (DFE) structure adopting spatial diversity scheme is effective in combating against multipath fading and inter-symbol interference (ISI) problem. In a SWAN, the receiver structure has the added task of suppressing co-channel interference (CCI) from other users, where DFE structures not employing multiuser detection strategy will often fail. This paper addresses the development of a multi-user detection strategy based on multistage recursive successive interference cancellation (RSIC) to suppress ISI and CCI in SWAN. The structure is then assessed with sea-trial data and results indicate that the RSIC structure is effective in mitigating the effect of ISI and CCI.
{"title":"Multiuser detection for time-variant multipath environment","authors":"H. K. Yeo, B. Sharif, A. Adams, O. Hinton","doi":"10.1109/UT.2000.852578","DOIUrl":"https://doi.org/10.1109/UT.2000.852578","url":null,"abstract":"Shallow water acoustic network (SWAN) communication has been an area of active research over the recent years. Due to the wave motion, the multipath components undergo time-varying propagation delays that result in signal attenuation and phase fluctuations. Although the adaptive decision feedback equalization (DFE) structure adopting spatial diversity scheme is effective in combating against multipath fading and inter-symbol interference (ISI) problem. In a SWAN, the receiver structure has the added task of suppressing co-channel interference (CCI) from other users, where DFE structures not employing multiuser detection strategy will often fail. This paper addresses the development of a multi-user detection strategy based on multistage recursive successive interference cancellation (RSIC) to suppress ISI and CCI in SWAN. The structure is then assessed with sea-trial data and results indicate that the RSIC structure is effective in mitigating the effect of ISI and CCI.","PeriodicalId":397110,"journal":{"name":"Proceedings of the 2000 International Symposium on Underwater Technology (Cat. No.00EX418)","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114409687","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}
In an attempt to investigate the technical feasibility of a continuous-wave Doppler sonar, we have examined a method of measuring low velocities with a high velocity resolution, or frequency resolution, by use of a simple circuit configuration employing digital signal processing technique. The following discussion presents the results of the investigation. In the measuring method described below, the fast Fourier transform (FFT) of undersampled data is calculated and the Doppler shift is obtained by searching for a peak frequency of the power spectrum. To achieve the intended frequency resolution of 1 Hz by FFT operation, measurement of data for a minimum measuring period of 1 second is essential. If the sampling frequency is set to 50 kHz, the number of samples obtained during the minimum measuring period of 1 second would amount to 50000. This is not practical in the light of the time required for the FFT operation. To overcome this problem, our new measuring method employs decimation technique for reducing the number of samples down to 1024 while maintaining a frequency resolution of about 1 Hz. This paper describes how the processing time can be drastically reduced to about 1/300 compared to the conventional technique by a combination of complex exponential functions, filtering and decimation, and thereby indicates the possibility of real-time continuous-wave Doppler data processing.
{"title":"A fast algorithm for high-accuracy frequency measurement. Application to ultrasonic Doppler sonar","authors":"H. Susaki","doi":"10.1109/UT.2000.852526","DOIUrl":"https://doi.org/10.1109/UT.2000.852526","url":null,"abstract":"In an attempt to investigate the technical feasibility of a continuous-wave Doppler sonar, we have examined a method of measuring low velocities with a high velocity resolution, or frequency resolution, by use of a simple circuit configuration employing digital signal processing technique. The following discussion presents the results of the investigation. In the measuring method described below, the fast Fourier transform (FFT) of undersampled data is calculated and the Doppler shift is obtained by searching for a peak frequency of the power spectrum. To achieve the intended frequency resolution of 1 Hz by FFT operation, measurement of data for a minimum measuring period of 1 second is essential. If the sampling frequency is set to 50 kHz, the number of samples obtained during the minimum measuring period of 1 second would amount to 50000. This is not practical in the light of the time required for the FFT operation. To overcome this problem, our new measuring method employs decimation technique for reducing the number of samples down to 1024 while maintaining a frequency resolution of about 1 Hz. This paper describes how the processing time can be drastically reduced to about 1/300 compared to the conventional technique by a combination of complex exponential functions, filtering and decimation, and thereby indicates the possibility of real-time continuous-wave Doppler data processing.","PeriodicalId":397110,"journal":{"name":"Proceedings of the 2000 International Symposium on Underwater Technology (Cat. No.00EX418)","volume":"154 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123443882","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}
A compact, portable and sensitive instrument has been designed and built for in-situ spectrophotometric analyses on aqueous solutions. This sensor, known as the spectral elemental analysis system (SEAS), has been successfully used for nutrient and pH measurements on both autonomous underwater vehicles (AUVs) and on moored platforms. The key element of SEAS is a liquid-core waveguide made of Teflon AF-2400 that permits long optical path lengths (several meters) in a very small volume (/spl sim/40 cm/sup 3/). Using SEAS, sub-nanomolar detection limits have been achieved for a wide variety of analyses. A unique feature of SEAS is the minimal reconfiguration required to perform fluorimetric analyses. Characteristics of the SEAS instrument are described, including laboratory and field measurements.
{"title":"A compact, in-situ, spectrophotometric sensor for aqueous environments: design and applications","authors":"E. Kaltenbacher, E. Steimle, R. Byrne","doi":"10.1109/UT.2000.852513","DOIUrl":"https://doi.org/10.1109/UT.2000.852513","url":null,"abstract":"A compact, portable and sensitive instrument has been designed and built for in-situ spectrophotometric analyses on aqueous solutions. This sensor, known as the spectral elemental analysis system (SEAS), has been successfully used for nutrient and pH measurements on both autonomous underwater vehicles (AUVs) and on moored platforms. The key element of SEAS is a liquid-core waveguide made of Teflon AF-2400 that permits long optical path lengths (several meters) in a very small volume (/spl sim/40 cm/sup 3/). Using SEAS, sub-nanomolar detection limits have been achieved for a wide variety of analyses. A unique feature of SEAS is the minimal reconfiguration required to perform fluorimetric analyses. Characteristics of the SEAS instrument are described, including laboratory and field measurements.","PeriodicalId":397110,"journal":{"name":"Proceedings of the 2000 International Symposium on Underwater Technology (Cat. No.00EX418)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122052047","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}
Two discontinuous solutions for the kinematic position and attitude closed loop control problem of an underactuated floating body are considered. The first is derived on the basis of Lyapunov's stability theory while the second is designed exploiting a novel idea: first a vector field is defined such that an ideal point free to move in any direction would exponentially converge to the desired configuration and then a steering law for the underactuated vehicle is derived such that it is exponentially parallel to the above mentioned field. Both solutions yield cusp-free and asymptotically null curvature paths which is a major practical constraint in real world applications.
{"title":"On a closed loop time invariant position control solution for an underactuated 3D underwater vehicle: implementation, stability and robustness considerations","authors":"M. Aicardi, Gabriella Casalino, G. Indiveri","doi":"10.1109/UT.2000.852592","DOIUrl":"https://doi.org/10.1109/UT.2000.852592","url":null,"abstract":"Two discontinuous solutions for the kinematic position and attitude closed loop control problem of an underactuated floating body are considered. The first is derived on the basis of Lyapunov's stability theory while the second is designed exploiting a novel idea: first a vector field is defined such that an ideal point free to move in any direction would exponentially converge to the desired configuration and then a steering law for the underactuated vehicle is derived such that it is exponentially parallel to the above mentioned field. Both solutions yield cusp-free and asymptotically null curvature paths which is a major practical constraint in real world applications.","PeriodicalId":397110,"journal":{"name":"Proceedings of the 2000 International Symposium on Underwater Technology (Cat. No.00EX418)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122739141","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}
This paper describes the development of autonomous underwater vehicle using variable vector propellers with the distributed controller and underwater acoustic communication system. Also presented is a novel technique of controlling the servomotors using the field programmable gate array (FPGA). Moreover, this paper also describes the 3D positioning technique for underwater vehicle. The digital signal processing by FPGA technology has enabled us to build compact, fast and highly reliable systems.
{"title":"Compact underwater vehicle with acoustic link for communication and positioning","authors":"J. Mian, T. Ishimatsu, Y. Nagashima","doi":"10.1109/UT.2000.852550","DOIUrl":"https://doi.org/10.1109/UT.2000.852550","url":null,"abstract":"This paper describes the development of autonomous underwater vehicle using variable vector propellers with the distributed controller and underwater acoustic communication system. Also presented is a novel technique of controlling the servomotors using the field programmable gate array (FPGA). Moreover, this paper also describes the 3D positioning technique for underwater vehicle. The digital signal processing by FPGA technology has enabled us to build compact, fast and highly reliable systems.","PeriodicalId":397110,"journal":{"name":"Proceedings of the 2000 International Symposium on Underwater Technology (Cat. No.00EX418)","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123941676","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}
To achieve the maximum detection range for active sonar systems, it is desirable to maximize their acoustic power. To do so, there are two limitations which are caused by cavitation on the face of the transducer and interaction effect between transducer elements of the array. To avoid these limitations, a method to drive each array element to yield the desired radiation uniform in-phase velocity of motion is proposed. For this purpose, the sonar transducer array which has internal accelerometers for monitoring the motion of the transducer element was developed. This paper presents an outline of this sonar array and a high speed numerical calculation method for the prediction of the radiation characteristics of the array using DFT algorithm.
{"title":"Self-monitoring sonar transducer array with the internal accelerometers","authors":"T. Musha, H. Uchida, M. Nagashima","doi":"10.1109/UT.2000.852570","DOIUrl":"https://doi.org/10.1109/UT.2000.852570","url":null,"abstract":"To achieve the maximum detection range for active sonar systems, it is desirable to maximize their acoustic power. To do so, there are two limitations which are caused by cavitation on the face of the transducer and interaction effect between transducer elements of the array. To avoid these limitations, a method to drive each array element to yield the desired radiation uniform in-phase velocity of motion is proposed. For this purpose, the sonar transducer array which has internal accelerometers for monitoring the motion of the transducer element was developed. This paper presents an outline of this sonar array and a high speed numerical calculation method for the prediction of the radiation characteristics of the array using DFT algorithm.","PeriodicalId":397110,"journal":{"name":"Proceedings of the 2000 International Symposium on Underwater Technology (Cat. No.00EX418)","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125400091","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}
To meet the needs of ocean exploitation, manned submersibles, ROV, untethered submersibles etc. have been developed in China since the early 70's. The first manned submersible had a length of 15 meters, 35 tons of displacement and the capability of diving to a depth of 600 meters and was successfully put into service in 1986. The first ROV was developed and reached a depth of 199 meters in an ocean experiment in 1986. In the meantime, a series of observing submersibles such as JH01, SJT-5, SJT-10, SJT-40 and atmospheric diving suits KZF-1 and QSZ-1 were developed and most of them have been used in diving experiments. From 1990 China Academy of Science and SJTU also developed the autonomous vehicle Explorer-1 and CR-01 etc. In 1995 the 6,000 meters deep tow survey system was co-developed by SJTU and DOE. The system completed the task successfully in 1998. The subsea pipeline and cable burying, inspection and maintenance technology is being developed by SJTU and ShengLi Oil Company.
{"title":"Undersea research activity in China","authors":"Zhu Ji-mao","doi":"10.1109/UT.2000.852558","DOIUrl":"https://doi.org/10.1109/UT.2000.852558","url":null,"abstract":"To meet the needs of ocean exploitation, manned submersibles, ROV, untethered submersibles etc. have been developed in China since the early 70's. The first manned submersible had a length of 15 meters, 35 tons of displacement and the capability of diving to a depth of 600 meters and was successfully put into service in 1986. The first ROV was developed and reached a depth of 199 meters in an ocean experiment in 1986. In the meantime, a series of observing submersibles such as JH01, SJT-5, SJT-10, SJT-40 and atmospheric diving suits KZF-1 and QSZ-1 were developed and most of them have been used in diving experiments. From 1990 China Academy of Science and SJTU also developed the autonomous vehicle Explorer-1 and CR-01 etc. In 1995 the 6,000 meters deep tow survey system was co-developed by SJTU and DOE. The system completed the task successfully in 1998. The subsea pipeline and cable burying, inspection and maintenance technology is being developed by SJTU and ShengLi Oil Company.","PeriodicalId":397110,"journal":{"name":"Proceedings of the 2000 International Symposium on Underwater Technology (Cat. No.00EX418)","volume":"34 10","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120819814","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}
The Institute of Ocean and Systems Engineering at Florida Atlantic University is currently developing a new generation of autonomous underwater vehicle (AUV), the MiniAUV. One major objective in its development is to provide a higher degree of navigation accuracy than the former generation of vehicle, the Ocean Explorer could achieve. To this end an embedded, real-time inertial navigation system has been developed for the past two years. It integrates high-precision navigation sensors while performing high frequency filtering and extensive data fusion methods, including a standard and an extended Kalman filter. This paper presents both the hardware and software architectures of the navigation system. Although the system is not fully operational yet, preliminary results were produced and are presented to illustrate the different features of the system.
{"title":"Enhancement of the inertial navigation system of the Florida Atlantic University autonomous underwater vehicles","authors":"G. Grenon, E. An, S. Smith","doi":"10.1109/UT.2000.852580","DOIUrl":"https://doi.org/10.1109/UT.2000.852580","url":null,"abstract":"The Institute of Ocean and Systems Engineering at Florida Atlantic University is currently developing a new generation of autonomous underwater vehicle (AUV), the MiniAUV. One major objective in its development is to provide a higher degree of navigation accuracy than the former generation of vehicle, the Ocean Explorer could achieve. To this end an embedded, real-time inertial navigation system has been developed for the past two years. It integrates high-precision navigation sensors while performing high frequency filtering and extensive data fusion methods, including a standard and an extended Kalman filter. This paper presents both the hardware and software architectures of the navigation system. Although the system is not fully operational yet, preliminary results were produced and are presented to illustrate the different features of the system.","PeriodicalId":397110,"journal":{"name":"Proceedings of the 2000 International Symposium on Underwater Technology (Cat. No.00EX418)","volume":"96 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127250569","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}
Pan-Mook Lee, B. Jeon, Seok-Won Hong, Yong-Kon Lim, Chong-moo Lee, Jong-Won Park, Chang-Min Lee
A remotely operated vehicle (ROV) equipped with two manipulators and an underwater stereo camera is being developed in KRISO (Korea Research Institute of Ships and Ocean Engineering) for seabed working. This paper describes the preliminary design of the ROV. An underwater stereo camera has been developed to enhance the working efficiency of the ROV with the manipulator in seabed operation. This paper presents the operational principle and the structure of the underwater stereo camera. The stereo camera consists of two CCD cameras and horizontally moving base, and it is embedded in a small pressure canister for underwater application. This paper also evaluates the implementation of an adaptive controller to the tracking control of the ROV/manipulator system.
{"title":"System design of an ROV with manipulators and adaptive control of it","authors":"Pan-Mook Lee, B. Jeon, Seok-Won Hong, Yong-Kon Lim, Chong-moo Lee, Jong-Won Park, Chang-Min Lee","doi":"10.1109/UT.2000.852583","DOIUrl":"https://doi.org/10.1109/UT.2000.852583","url":null,"abstract":"A remotely operated vehicle (ROV) equipped with two manipulators and an underwater stereo camera is being developed in KRISO (Korea Research Institute of Ships and Ocean Engineering) for seabed working. This paper describes the preliminary design of the ROV. An underwater stereo camera has been developed to enhance the working efficiency of the ROV with the manipulator in seabed operation. This paper presents the operational principle and the structure of the underwater stereo camera. The stereo camera consists of two CCD cameras and horizontally moving base, and it is embedded in a small pressure canister for underwater application. This paper also evaluates the implementation of an adaptive controller to the tracking control of the ROV/manipulator system.","PeriodicalId":397110,"journal":{"name":"Proceedings of the 2000 International Symposium on Underwater Technology (Cat. No.00EX418)","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114197094","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}
S. Vandenplas, A.B. Temsamani, Z. Cisneros, L. van Biesen
This paper presents a global system identification method for the inverse problem to the parametric modeling of the acoustic wave propagation through sediments, tested in the laboratory. A general viscoelastic model which considers beam-spread due to the finite aperture of the emitter, losses due to absorption and dispersion along the propagation path of the wave in the sediment, and roughness of the sediment surface is used to describe the acoustic wave propagation. The estimation of the model parameters is elaborated using a maximum likelihood estimator in a MIMO (multiple input-multiple output) configuration. The estimated absorption and dispersion in the sediment are depicted.
{"title":"A MIMO inversion technique applied to reflected signals from a simulated seafloor","authors":"S. Vandenplas, A.B. Temsamani, Z. Cisneros, L. van Biesen","doi":"10.1109/UT.2000.852569","DOIUrl":"https://doi.org/10.1109/UT.2000.852569","url":null,"abstract":"This paper presents a global system identification method for the inverse problem to the parametric modeling of the acoustic wave propagation through sediments, tested in the laboratory. A general viscoelastic model which considers beam-spread due to the finite aperture of the emitter, losses due to absorption and dispersion along the propagation path of the wave in the sediment, and roughness of the sediment surface is used to describe the acoustic wave propagation. The estimation of the model parameters is elaborated using a maximum likelihood estimator in a MIMO (multiple input-multiple output) configuration. The estimated absorption and dispersion in the sediment are depicted.","PeriodicalId":397110,"journal":{"name":"Proceedings of the 2000 International Symposium on Underwater Technology (Cat. No.00EX418)","volume":"390 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123262289","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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