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Proceedings of OCEANS '93最新文献

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Ocean mass simulator for underwater LIDAR applications 用于水下激光雷达的海洋质量模拟器
Proceedings of OCEANS '93 Pub Date : 1993-10-18 DOI: 10.1109/OCEANS.1993.326121
L. Mullen, P. Herczfeld, V. Contarino, D. Allocca, M. Squicciarini, R. Billmers
{"title":"Ocean mass simulator for underwater LIDAR applications","authors":"L. Mullen, P. Herczfeld, V. Contarino, D. Allocca, M. Squicciarini, R. Billmers","doi":"10.1109/OCEANS.1993.326121","DOIUrl":"https://doi.org/10.1109/OCEANS.1993.326121","url":null,"abstract":"Since microwaves are both reflected and absorbed by water, radar techniques cannot be utilized in the detection of underwater objects. For this situation, light detecting and ranging methods (LIDAR) are used. However, unlike radar, conventional LIDAR systems do not allow for coherent detection techniques which results in a loss in system sensitivity. Therefore, it is proposed that by combining millimeter wave and optical techniques, new coherent detection schemes can be developed. The transmitted optical signal in a LIDAR system is subject to attenuation, distributed backscattering, and dispersion as it propagates through the sea water. Since the goal of the project is to test hybrid microwave-LIDAR signal processing techniques, a simple, inexpensive method is needed to simulate the water medium. The backscattered signal from plastic optical fiber is examined to qualify the fiber as an accurate model of different types of sea water.<<ETX>>","PeriodicalId":130255,"journal":{"name":"Proceedings of OCEANS '93","volume":"114 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":"115258262","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}
引用次数: 4
Statistics of shallow water, high-frequency acoustic scattering and propagation 浅水统计，高频声散射和传播
Proceedings of OCEANS '93 Pub Date : 1993-10-18 DOI: 10.1109/OCEANS.1993.326024
M. A. Wilson, R. W. Farwell, S. Stanic
{"title":"Statistics of shallow water, high-frequency acoustic scattering and propagation","authors":"M. A. Wilson, R. W. Farwell, S. Stanic","doi":"10.1109/OCEANS.1993.326024","DOIUrl":"https://doi.org/10.1109/OCEANS.1993.326024","url":null,"abstract":"During August 1991, the Naval Research Laboratory conducted high-frequency shallow water acoustic scattering experiments in the Gulf of Mexico near Panama City, Florida. The acoustic measurements included surface and bottom reverberation, surface and bottom forward scattering, and direct path propagation. The results reported are confined to the direct and bottom forward reflected paths and include the statistical characteristics of three signals; namely, the direct, the bottom reflected, and the direct plus the bottom reflected. Representative envelopes will be presented that illustrate the complexity of the shallow water environment statistics, including the means, variances, and probability distributions for each signal, are presented to discern any differences that can be exploited in the detection process. The frequency range covered during the experiment was from 20 to 180 kHz. The supporting environmental measurements included sound speed profiles, currents, wave heights, and bottom samples.<<ETX>>","PeriodicalId":130255,"journal":{"name":"Proceedings of OCEANS '93","volume":"30 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":"122679985","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}
引用次数: 4
Surface sensing method 表面传感法
Proceedings of OCEANS '93 Pub Date : 1993-10-18 DOI: 10.1109/OCEANS.1993.325955
S. A. Sviridov, A.I. Sudbin
{"title":"Surface sensing method","authors":"S. A. Sviridov, A.I. Sudbin","doi":"10.1109/OCEANS.1993.325955","DOIUrl":"https://doi.org/10.1109/OCEANS.1993.325955","url":null,"abstract":"In recent years there has been a growing need for the ability to measure ocean waves in the limited area of water from a moving vessel or ashore when special survey conditions are needed. For these problems a new grazing laser remote sensing method has been designed at the P.P. Shirshov Institute of Oceanology. It is based on the pulse laser range finder method and light volume dissipation in the water. The method allows the determination of significant wave height estimates and spectral maximum frequencies. The system senses the level of the sea surface by sending short laser pulses to the sea. The back scattered pulse is detected by the optical receiver due to the light volume dissipation in the sea surface water layer. The simple reconstructed system optimises an informational capability of lidar remote technology and could be used for multipurpose open sea oceanological applications.<<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":"122511746","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}
引用次数: 1
Recent results in model-based wind retrieval 基于模型的风检索的最新成果
Proceedings of OCEANS '93 Pub Date : 1993-10-18 DOI: 10.1109/OCEANS.1993.326040
D. Long, J. Gunther
{"title":"Recent results in model-based wind retrieval","authors":"D. Long, J. Gunther","doi":"10.1109/OCEANS.1993.326040","DOIUrl":"https://doi.org/10.1109/OCEANS.1993.326040","url":null,"abstract":"From multiple measurements of the normalized radar backscatter (/spl sigmaspl deg/) made by a spaceborne scatterometer, the near-surface wind over the ocean can be inferred using a geophysical model function relating /spl sigmaspl deg/ and the vector wind. Recently, a model-based retrieval technique has been developed. The technique avoids many of the problems associated with traditional point-wise wind retrieval and ambiguity removal. The model-based retrieval can also produce vorticity and divergence fields as auxiliary products. In this paper the method is applied to ERS-1 scatterometer data. Comparisons in performance between the traditional two-step pointwise wind retrieval/ambiguity removal method and the model-based retrieval method are presented using simulated and actual ERS-1 measurements. The results suggest that model-based retrieval can produce more accurate estimates of the wind field than pointwise wind retrieval-particularily in low wind speed regions where the C-band model function results in low wind accuracy for traditional wind estimation. The authors consider the spectra of the wind and wind vorticity over scales of from 50 to 1000 km.<<ETX>>","PeriodicalId":130255,"journal":{"name":"Proceedings of OCEANS '93","volume":"25 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":"129582091","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}
引用次数: 0
Cramer-Rao lower bounds for multi-sensor localization 多传感器定位的Cramer-Rao下界
Proceedings of OCEANS '93 Pub Date : 1993-10-18 DOI: 10.1109/OCEANS.1993.326100
J. Fawcett, B. Maranda
{"title":"Cramer-Rao lower bounds for multi-sensor localization","authors":"J. Fawcett, B. Maranda","doi":"10.1109/OCEANS.1993.326100","DOIUrl":"https://doi.org/10.1109/OCEANS.1993.326100","url":null,"abstract":"The Cramer-Rao lower bound is used to assess the potential localization accuracy of multiple arrays observing a narrowband moving target. The narrowband signal received by the array is assumed to have only partial temporal coherence, which is modelled by taking the signal to be completely coherent over a data block but with an unknown absolute phase from block to block. The signal may also have unknown phase differences between different sets of sensors. Including these unknown phases in the model enables to account for the spatial incoherence of the signal between arrays. Examples of the localization accuracy possible for multi-array or multi-sensor systems as a function of target position are given.<<ETX>>","PeriodicalId":130255,"journal":{"name":"Proceedings of OCEANS '93","volume":"98 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":"128393676","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}
引用次数: 1
An investigation of two body forces in a vortex wake 涡旋尾流中两个体力的研究
Proceedings of OCEANS '93 Pub Date : 1993-10-18 DOI: 10.1109/OCEANS.1993.325972
M. Munzel
{"title":"An investigation of two body forces in a vortex wake","authors":"M. Munzel","doi":"10.1109/OCEANS.1993.325972","DOIUrl":"https://doi.org/10.1109/OCEANS.1993.325972","url":null,"abstract":"Summary form only given. Computer models and tow-tank trials are being used to study the roll behavior of a sonar twobody in two-part underwater twoing. Two-part two configurations, consisting of a depressor generating downforce on the main two cable to hold down a neutrally-buoyant connecting cable and twobody, are used to isolate towed devices from ship motion. However, during sea trials of one such arrangement with a hydrodynamic depressor, the twobody would periodically roll violently. This unacceptable motion was believed to be caused by the two trailing vortices which dominate the delta-shaped depressor's wake. An investigation has commenced into this problem and how it might be avoided. First, a series of computer programs for estimating the wake's influence on the twobody is being written. The initial code uses potential-flow calculations in the body's crossflow plane to determine the instantaneous lift, sideforce, and roll moment induced on the tail section by a pair of ideal vortices. A later version will consider viscous boundary layer and vortex-core effects. The first simulation has been run for a range of twobody positions relative to the wake. Its results show that large moments are generated when the body is very close to the vortices, and that the lift and sideforce can move the body into such hazardous proximity over time. To verify the simulation output, depressor-generated forces on the actual body are to be measured in a two tank. Trials will be run for several twobody positions to validate the predictions of the computer models. This project represents a novel approach to twoing simulation. The complete investigation should confirm that the depressor's wake induces twobody roll, and reveal twoing situations which must be avoided. The results can be used as a guide to adjusting two-part two configurations to maintain stability.<<ETX>>","PeriodicalId":130255,"journal":{"name":"Proceedings of OCEANS '93","volume":"21 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":"128358015","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}
引用次数: 0
Development of a six degree of freedom buoy design and analysis program with validating data 开发了六自由度浮筒设计分析程序，并进行了数据验证
Proceedings of OCEANS '93 Pub Date : 1993-10-18 DOI: 10.1109/OCEANS.1993.325978
W. Venezia, A. M. Clark, K. Schmitt
{"title":"Development of a six degree of freedom buoy design and analysis program with validating data","authors":"W. Venezia, A. M. Clark, K. Schmitt","doi":"10.1109/OCEANS.1993.325978","DOIUrl":"https://doi.org/10.1109/OCEANS.1993.325978","url":null,"abstract":"A six degree of freedom buoy design and analysis program is given. The buoy program extends original work published by the Woods Hole Oceanographic Institution for roll and heave response of free floating axisymetric bodies. The program predicts the probable amplitude of buoy displacement, velocity, acceleration, and jerk for heave, surge, and sway, motions and probable amplitude of roll, pitch, and yaw angular displacements, velocities, and accelerations. Given is an overview of the equations of motion, simplifying assumptions, and a description of the computational method. The paper contributes limited verification of the computational method with a summary of computer predictions and experimentally obtained data on buoy motion. The data on motions is obtained from buoys designed with specific buoy motion requirements. Experimental data is given for various sea states and buoy types.<<ETX>>","PeriodicalId":130255,"journal":{"name":"Proceedings of OCEANS '93","volume":"51 98 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":"124603020","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}
引用次数: 2
A coherent averaging technique for resolving directional wave spectra 解析定向波谱的相干平均技术
Proceedings of OCEANS '93 Pub Date : 1993-10-18 DOI: 10.1109/OCEANS.1993.326088
I. Booth, M. Trevorrow
{"title":"A coherent averaging technique for resolving directional wave spectra","authors":"I. Booth, M. Trevorrow","doi":"10.1109/OCEANS.1993.326088","DOIUrl":"https://doi.org/10.1109/OCEANS.1993.326088","url":null,"abstract":"A new technique has been developed for deriving the directional spreading function of ocean waves from an array of water velocity measurements. The objective was to efficiently process data from a 118 kHz Doppler sidescan sonar which measures water velocity parallel to the sonar beam at a series of ranges. The sonar beam rotates as it collects data, rendering techniques such as the maximum likelihood method unusable. A numerical process was developed wherein the data are transformed into wavenumber space, deconvoluted in space and time, and coherently averaged over successive sweeps of the sonar. The method was tested on velocity arrays simulated from computer models of the sea surface, and used on experimental data. It proved to be computationally efficient and very insensitive to noise.<<ETX>>","PeriodicalId":130255,"journal":{"name":"Proceedings of OCEANS '93","volume":"57 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":"124653599","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}
引用次数: 0
Real signals demodulation on a highly selective channel 在高选择性信道上的真实信号解调
Proceedings of OCEANS '93 Pub Date : 1993-10-18 DOI: 10.1109/OCEANS.1993.326243
H. Mariotte, P.Y. Cochet
{"title":"Real signals demodulation on a highly selective channel","authors":"H. Mariotte, P.Y. Cochet","doi":"10.1109/OCEANS.1993.326243","DOIUrl":"https://doi.org/10.1109/OCEANS.1993.326243","url":null,"abstract":"Summary form only given. The underwater acoustic channel is probably one of the most complicated environments for data communication. The characteristics of this channel, which include fading, multipath and therefore frequency selectivity, Doppler shift preclude direct application of standard communications techniques. But there are many situations in which it would be desirable to have the means to communicate underwater. The use of well known estimation methods for digital communication is the new approach of this paper. Indeed, the adaptation of the propagation parameters in the demodulation algorithm allows to improve the system performance. Moreover, the knowledge, a priori, of the emitted signals allows to calculate the error rate after the adaptive demodulation. This paper shows the main results obtained with real signals emitted in shallow water (testing pool and ocean) and recorded on a DAT tape. The correlation figure of the received signals permits the estimation of time delay and attenuation of the different paths. The figure of phase estimation and tracking allows the extraction of the Doppler shift for each path. The comparison between the error rate performance with and without adaptive demodulation shows the improvement brought by this demodulation.<<ETX>>","PeriodicalId":130255,"journal":{"name":"Proceedings of OCEANS '93","volume":"2 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":"124706636","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}
引用次数: 0
WSD/barometric test buoys deployed in the Gulf of Mexico 在墨西哥湾部署的水务署/气压测试浮标
Proceedings of OCEANS '93 Pub Date : 1993-10-18 DOI: 10.1109/OCEANS.1993.326075
N. Van de Voorde, E. Michelena
{"title":"WSD/barometric test buoys deployed in the Gulf of Mexico","authors":"N. Van de Voorde, E. Michelena","doi":"10.1109/OCEANS.1993.326075","DOIUrl":"https://doi.org/10.1109/OCEANS.1993.326075","url":null,"abstract":"Two drifting buoys were configured to accept, process, and transmit barometric pressure signals from three independent low-cost pressure transducers. The \"smart barometer\" concept is based upon the use of an inexpensive, but stable pressure sensor in conjunction with a microprocessor. The pressure transducers were calibrated to remove their temperature biases with a data correction algorithm, thus establishing the basis for a reliable, accurate, and inexpensive electronic barometer.<<ETX>>","PeriodicalId":130255,"journal":{"name":"Proceedings of OCEANS '93","volume":"51 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":"124764834","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}
引用次数: 0
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