Proceedings of OCEANS '93最新文献

{"title":"Adaptive filter applications to autonomous underwater vehicle","authors":"D. Lainiotis, D. Menon, K. Plataniotis, C. Charalampous","doi":"10.1109/OCEANS.1993.326109","DOIUrl":"https://doi.org/10.1109/OCEANS.1993.326109","url":null,"abstract":"A powerful adaptive filter algorithm for estimation of forces acting on an Autonomous Underwater Vehicle (AUV) and the corresponding adaptive control law which determines the desired heading commands are considered in this paper. Due to the complicated nature of AUV's task and incorporation of the ocean current, uncertain parameters arise in the equations of motion that constitute the AUV's dynamic model. Based on the Lainiotis Partitioning Theory, a highly adaptive scheme is used to estimate the velocity components for controlling the vehicle. Extensive simulations demonstrate the robustness and the effectiveness of the new scheme in a variety of different environments.<<ETX>>","PeriodicalId":130255,"journal":{"name":"Proceedings of OCEANS '93","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1993-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130107845","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}

{"title":"Bioacoustic surveys of planktonic sound scatterers and of their diel and seasonal variability in the northwest Gulf of Mexico","authors":"R. A. Zimmerman, H. C. Biggs, A. Anderson","doi":"10.1109/OCEANS.1993.325977","DOIUrl":"https://doi.org/10.1109/OCEANS.1993.325977","url":null,"abstract":"A vessel-mounted 150 kHz acoustic Doppler current profiler (ADCP), which is employed to gather underway data on near-surface current velocity, was used in March and June 1992 to survey plankton stocks using backscattered ADCP signal intensity. Relative backscatter intensity was calibrated with salinity-temperature-depth data from CTD casts to determine an absolute backscatter intensity in decibels (dB) in 8 m bins, from 16 to 320 m. Time versus depth matrices were then constructed to display temporal and spatial patterns of aggregations of sound scatterers.<<ETX>>","PeriodicalId":130255,"journal":{"name":"Proceedings of OCEANS '93","volume":"164 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1993-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133505718","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}

{"title":"Acoustical remote sensing of energy dissipation using scintillation analysis","authors":"D. Menemenlis, D. Farmer","doi":"10.1109/OCEANS.1993.325992","DOIUrl":"https://doi.org/10.1109/OCEANS.1993.325992","url":null,"abstract":"Forward-scattered sound propagating through turbulent fluids produces characteristic scintillation patterns which have been interpreted in terms of refractive index fine structure and mean transverse motion of the flows under study. Reciprocal travel-time measurements yield information about velocity variability along the acoustic path. By combining these two types of measurements, the contributions of sound speed and velocity fluctuations to forward acoustic scatter can be separated. These techniques are illustrated using measurements outlined in the boundary layer under ice in the Arctic. Under the assumptions of a Kolmogorov inertial subrange and Taylor's frozen field hypothesis, reciprocal travel-time measurements provide estimates of turbulent kinetic energy dissipation rate averaged over the propagation paths. Sound speed variability is negligible in the Arctic boundary layer; for this reason, acoustic scintillation analysis also yields estimates of energy dissipation rate which compare well with those obtained from reciprocal travel-time measurements.<<ETX>>","PeriodicalId":130255,"journal":{"name":"Proceedings of OCEANS '93","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1993-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132148458","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}

{"title":"Real-time acoustic bottom classification for hydrography a field evaluation of RoxAnn","authors":"G.E.O. Schiagintweit","doi":"10.1109/OCEANS.1993.326188","DOIUrl":"https://doi.org/10.1109/OCEANS.1993.326188","url":null,"abstract":"A specific analysis of reflected acoustic signals enables real-time bottom classification during hydrographic operations using modern signal processing technology. Supplementary seabed data can be collected and portrayed for considerations such as ground fish habitat evaluation, shellfish distributions, oil spillage residue mapping, and pre-dredging analysis. An instrument which performs this task is described and evaluated.<<ETX>>","PeriodicalId":130255,"journal":{"name":"Proceedings of OCEANS '93","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1993-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132235183","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}

{"title":"Underwater cableless data transmission","authors":"J. P. von der Weid, J.A.P. da Silva, A. Sant'Anna","doi":"10.1109/OCEANS.1993.326184","DOIUrl":"https://doi.org/10.1109/OCEANS.1993.326184","url":null,"abstract":"An optical cableless data transmission link for underwater operation at ranges up to 20 m is presented. The system is bidirectional and uniaxial, and uses a red laser diode as optical source. Data rates up to 14,700 Baud can be transmitted.<<ETX>>","PeriodicalId":130255,"journal":{"name":"Proceedings of OCEANS '93","volume":"147 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1993-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133130871","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}

{"title":"Velocity, concentration and flux of sediments in a coastal bottom boundary layer with a laser Doppler velocimeter","authors":"Y. Agrawal, H.H. Trowbridge, H. C. Pottsmith, J. Oltman-Shay","doi":"10.1109/OCEANS.1993.326174","DOIUrl":"https://doi.org/10.1109/OCEANS.1993.326174","url":null,"abstract":"A backscatter fiber-optic laser Doppler velocimeter (LDV) mounted on a profiler was used to obtain velocity measurement in a coastal bottom boundary layer. The rate of velocity realization from the LDV has been used to obtain profiles of sediment concentration and flux. The instrumentation and the method for extraction of concentration and flux profile information are described. Analysis of results of interest to hydrodynamics is deferred to a later paper.<<ETX>>","PeriodicalId":130255,"journal":{"name":"Proceedings of OCEANS '93","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1993-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133166539","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}

{"title":"Data from the sea..., the U.S. Navy's AN/WSQ-6 (series) drifting buoy program","authors":"H. D. Selsor","doi":"10.1109/OCEANS.1993.326079","DOIUrl":"https://doi.org/10.1109/OCEANS.1993.326079","url":null,"abstract":"A prime objective of Naval Oceanography is to get data, \"From the sea...,\" and quickly into the hands of the Fleet operators whose safety, sensors, and systems are influenced by it. Changing world politics and economics will undoubtedly reduce the number of maritime observations in the future with increasing reliance being made on automated reporting systems. The Oceanographer of the Navy has been investigating methods to reduce reliance on single profile expendables and ship observations by development of a series of satellite reporting expendable drifting buoys. These buoys will be capable of measuring air temperature, sea surface temperature, barometric pressure, subsurface ocean temperature with depth, ambient noise, wind speed, wind direction, and directional wave spectra. These developmental buoys have been designated by the Navy as the AN/WSQ-6 (series) drifting buoys. This paper updates some of the Navy's recent testing of these buoys and provides insight into the engineering challenges ahead for additional sensor development.<<ETX>>","PeriodicalId":130255,"journal":{"name":"Proceedings of OCEANS '93","volume":"63 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1993-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115387853","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}

{"title":"Sea clutter measurements using an airborne X-band radar","authors":"W. Stehwien","doi":"10.1109/OCEANS.1993.326036","DOIUrl":"https://doi.org/10.1109/OCEANS.1993.326036","url":null,"abstract":"Litton Systems Canada Limited is engaged in a program of collecting and analyzing sea clutter data for the purpose of developing improved target detection algorithms for its airborne X-band maritime surveillance radar. Limited amounts of high-resolution clutter data have been recorded. Statistical analyses have reconfirmed known characteristics of clutter, and have revealed new information, particularly as it relates to the specific pulses and processing techniques used by this type of radar. Some of these results are presented, and preliminary interpretations are offered.<<ETX>>","PeriodicalId":130255,"journal":{"name":"Proceedings of OCEANS '93","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1993-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115488094","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}

{"title":"Prediction of submersible maneuvering performance at high incidence angles","authors":"K. Watson, J. S. Webster, J. Crane, N. S. Smith","doi":"10.1109/OCEANS.1993.326108","DOIUrl":"https://doi.org/10.1109/OCEANS.1993.326108","url":null,"abstract":"A model is described to predict the hydrodynamic loads on an underwater vehicle at high incidence angles. The model has been implemented into a trajectory program to allow the prediction of highly nonlinear maneuvers such as low speed hovering and vertical rise and descent. Two key features of the model are the ability to predict out-of-plane loads due to asymmetric hull vortex shedding and fin loads through the linear, stall and post-stall flow regimes. Model validation was performed by comparing predicted total force and moment coefficients with missile and airship data.<<ETX>>","PeriodicalId":130255,"journal":{"name":"Proceedings of OCEANS '93","volume":"156 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1993-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115744743","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}

{"title":"Simulating underwater acoustic data using random variable transformations","authors":"S. Gordon","doi":"10.1109/OCEANS.1993.325970","DOIUrl":"https://doi.org/10.1109/OCEANS.1993.325970","url":null,"abstract":"Recent advances in underwater acoustics have shown the non-gaussian nature of acoustic signals in a random ocean. These advances have also demonstrated that the probability distribution of the amplitude of an acoustic signal is modeled quite well by the generalized gamma density function. This model is further developed in this study to include a phase distribution. This non-gaussian nature makes it difficult to simulate data needed to develop new signal processing methods for source localization. However, with the knowledge of these two first order statistics, a method for simulating a random ocean based purely on its statistical properties and using random variable transformations is presented. Although an accurate model for both the phase distribution and the amplitude distribution can be obtained, because of the non-gaussian nature of the acoustic signals, it is a more difficult problem to find the joint probability distribution of the two components. In the author's model for the phase distribution, referred to as the ricean model in communication literature, there is an inherent model for the amplitude distribution as well. This model also provides a convenient expression for the joint probability density function of the amplitude and phase. Hence, by using this model, random data can be created which have a known amplitude, phase and joint distribution. However, this amplitude distribution does not describe what is observed in practice. To overcome this problem, the idea of transforming random variables is used. In this idea, the generalized gamma amplitude distribution is obtained by passing the author's amplitude distribution model through a non-linearity while the phase is left unperturbed. The resulting amplitude and phase distributions match what is observed in practice for the single point statistics of a random ocean. Furthermore, by using the ricean model, a dependence between the amplitude and phase has been introduced, albeit somewhat modified by the non-linearity. Although it is difficult to solve for this transformation in closed form, numerically it is quite simple. This process does not give much insight into the resulting joint phase and amplitude distribution, but it does provide an excellent means to simulate data of a random ocean based only on its statistical properties. Furthermore, by correlating the data in some manner one can simulate the stochastic nature observed at a vertical array of hydrophones.<<ETX>>","PeriodicalId":130255,"journal":{"name":"Proceedings of OCEANS '93","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1993-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124407660","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}