Pub Date : 1993-10-18DOI: 10.1109/OCEANS.1993.326092
C. Ebbesmeyer, C.A. Coomes, W.V. Tangborn
Interdisciplinary synthesis of environmental data is necessary for comprehensive solutions to societal concerns. Three examples illustrate results of examining data drawn from a diverse array of environmental disciplines: (1) a jump in global climate; (2) covariation of many environmental parameters at periods of 10-20 years; and (3) the influence of summer-to-winter diversion of the Columbia River on coastal salinities. These results, obtained by small groups of researchers with modest budgets, argue for interdisciplinary data exchange.<>
{"title":"Interdisciplinary environmental information synthesis: examples of jumps, cycles, and trends in the North Pacific climate, 1930-1990","authors":"C. Ebbesmeyer, C.A. Coomes, W.V. Tangborn","doi":"10.1109/OCEANS.1993.326092","DOIUrl":"https://doi.org/10.1109/OCEANS.1993.326092","url":null,"abstract":"Interdisciplinary synthesis of environmental data is necessary for comprehensive solutions to societal concerns. Three examples illustrate results of examining data drawn from a diverse array of environmental disciplines: (1) a jump in global climate; (2) covariation of many environmental parameters at periods of 10-20 years; and (3) the influence of summer-to-winter diversion of the Columbia River on coastal salinities. These results, obtained by small groups of researchers with modest budgets, argue for interdisciplinary data exchange.<<ETX>>","PeriodicalId":130255,"journal":{"name":"Proceedings of OCEANS '93","volume":"43 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":"114012348","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 : 1993-10-18DOI: 10.1109/OCEANS.1993.326152
K. Davidson, J. Johannessen, R. Shuchman, R.A. Brown
SAR images obtained during an ERS-1 calibration/validation campaign conducted off the west coast of Norway, NORCSEX'91, are examined. The examination is based on in situ data including shipboard measured surface layer vector wind, thermal stability, and rawinsonde derived atmospheric boundary layer profiles. FFT analyses on the SAR images provided vector information on low-wavenumber structure. For two overpasses, derived direction and spatial separation for coherent structures were compared with model prediction for features of organized large planetary boundary layer eddies. The feature are related to the mixed-layer vector wind and depth. Predicted wind directions were in agreement with observed and mixed layer depths in relative agreement.<>
{"title":"Analysis and interpretation of ERS-1 SAR detected wind rows relative to observed air-sea interaction processes","authors":"K. Davidson, J. Johannessen, R. Shuchman, R.A. Brown","doi":"10.1109/OCEANS.1993.326152","DOIUrl":"https://doi.org/10.1109/OCEANS.1993.326152","url":null,"abstract":"SAR images obtained during an ERS-1 calibration/validation campaign conducted off the west coast of Norway, NORCSEX'91, are examined. The examination is based on in situ data including shipboard measured surface layer vector wind, thermal stability, and rawinsonde derived atmospheric boundary layer profiles. FFT analyses on the SAR images provided vector information on low-wavenumber structure. For two overpasses, derived direction and spatial separation for coherent structures were compared with model prediction for features of organized large planetary boundary layer eddies. The feature are related to the mixed-layer vector wind and depth. Predicted wind directions were in agreement with observed and mixed layer depths in relative agreement.<<ETX>>","PeriodicalId":130255,"journal":{"name":"Proceedings of OCEANS '93","volume":"219 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":"131111543","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 : 1993-10-18DOI: 10.1109/OCEANS.1993.326223
M. Pecoraro, G.D. Hugus
The paper presents the development of a 0-3 piezo-composite hydrophone, fabricated of new materials that is part of a portable, fiber optic, bottom mounted, in-line hydrophone array that will be used by the US Navy to track various test vehicles in shallow water.<>
{"title":"The development of an in-line hydrophone for a sea-bottom array with a unique 0-3 composite sensor element","authors":"M. Pecoraro, G.D. Hugus","doi":"10.1109/OCEANS.1993.326223","DOIUrl":"https://doi.org/10.1109/OCEANS.1993.326223","url":null,"abstract":"The paper presents the development of a 0-3 piezo-composite hydrophone, fabricated of new materials that is part of a portable, fiber optic, bottom mounted, in-line hydrophone array that will be used by the US Navy to track various test vehicles in shallow water.<<ETX>>","PeriodicalId":130255,"journal":{"name":"Proceedings of OCEANS '93","volume":"313 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":"131579003","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 : 1993-10-18DOI: 10.1109/OCEANS.1993.326171
D. Mellinger, C. Clark
A method is presented for detecting bioacoustic transients. The desired transient-an animal call-is modeled as a sequence of frequency sweeps. Sweeps are detected by convolving a spectrogram of the signal with a kernel designed for the call of interest; convolution output is high when the call of interest is present and low other times. The method is tested on a set of bowhead whale (Balaena mysticetus) calls recorded in a noisy Arctic environment. The method detects bowhead calls well, performing better than a matched filter and a hidden Markov model on the task. Strengths and weaknesses of the method are discussed.<>
{"title":"A method for filtering bioacoustic transients by spectrogram image convolution","authors":"D. Mellinger, C. Clark","doi":"10.1109/OCEANS.1993.326171","DOIUrl":"https://doi.org/10.1109/OCEANS.1993.326171","url":null,"abstract":"A method is presented for detecting bioacoustic transients. The desired transient-an animal call-is modeled as a sequence of frequency sweeps. Sweeps are detected by convolving a spectrogram of the signal with a kernel designed for the call of interest; convolution output is high when the call of interest is present and low other times. The method is tested on a set of bowhead whale (Balaena mysticetus) calls recorded in a noisy Arctic environment. The method detects bowhead calls well, performing better than a matched filter and a hidden Markov model on the task. Strengths and weaknesses of the method are discussed.<<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":"115139445","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 : 1993-10-18DOI: 10.1109/OCEANS.1993.325976
T. Orsi, A. L. Anderson
X-ray computed tomography (X-ray CT) images of a bioturbated sediment from the northern Gulf of Mexico continental shelf reveal clear evidence of two worm tubes, one circular and the other elliptical in plan view. Application of a segmentation technique using (CT number, gradient) feature space permitted a volumetric characterization of the tubes, which obtained results in good agreement with physical measurements. Although the tubes appear to be relict structures, a numerical exercise demonstrates that the tubes can increase the effective surface area of the seafloor locally by up to 23%. From this and through visualization of the dramatic modifications in the spatial density structure of the sediments, the importance of tubificid structures is clear: seafloor characterizations conducted in support of biogeochemical, geotechnical, and geoacoustic studies of bioturbated sediments are largely incomplete without a consideration of these features. The combination of X-ray CTR and digital image analysis is a powerful means to examine these features nondestructively and provide the necessary quantitative information for such purposes.<>
{"title":"Computed tomography of biological structures in marine sediments","authors":"T. Orsi, A. L. Anderson","doi":"10.1109/OCEANS.1993.325976","DOIUrl":"https://doi.org/10.1109/OCEANS.1993.325976","url":null,"abstract":"X-ray computed tomography (X-ray CT) images of a bioturbated sediment from the northern Gulf of Mexico continental shelf reveal clear evidence of two worm tubes, one circular and the other elliptical in plan view. Application of a segmentation technique using (CT number, gradient) feature space permitted a volumetric characterization of the tubes, which obtained results in good agreement with physical measurements. Although the tubes appear to be relict structures, a numerical exercise demonstrates that the tubes can increase the effective surface area of the seafloor locally by up to 23%. From this and through visualization of the dramatic modifications in the spatial density structure of the sediments, the importance of tubificid structures is clear: seafloor characterizations conducted in support of biogeochemical, geotechnical, and geoacoustic studies of bioturbated sediments are largely incomplete without a consideration of these features. The combination of X-ray CTR and digital image analysis is a powerful means to examine these features nondestructively and provide the necessary quantitative information for such purposes.<<ETX>>","PeriodicalId":130255,"journal":{"name":"Proceedings of OCEANS '93","volume":"134 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":"127625073","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 : 1993-10-18DOI: 10.1109/OCEANS.1993.326134
S. P. Miller, K. Macdonald, T. Atwater, R. Alexander, M. Cormier, D. Scheirer, C. Weiland, D. Wright, D. Forsyth, Y. Shen
Preliminary results are presented from an expedition to the ultra-fast spreading segment on the East Pacific Rise. The combined multibeam and sidescan sonar worked extremely well, and provided the authors with surprising discoveries of abundant off-axis volcanism. Individuals from several institutions have contributed to a collection of public domain software for processing and displaying SeaBeam 2000 data, much of which is being used to visualize the East Pacific Rise.<>
{"title":"Combined SeaBeam 2000 bathymetry and sidescan on the Melville: East Pacific Rise 15-19 S","authors":"S. P. Miller, K. Macdonald, T. Atwater, R. Alexander, M. Cormier, D. Scheirer, C. Weiland, D. Wright, D. Forsyth, Y. Shen","doi":"10.1109/OCEANS.1993.326134","DOIUrl":"https://doi.org/10.1109/OCEANS.1993.326134","url":null,"abstract":"Preliminary results are presented from an expedition to the ultra-fast spreading segment on the East Pacific Rise. The combined multibeam and sidescan sonar worked extremely well, and provided the authors with surprising discoveries of abundant off-axis volcanism. Individuals from several institutions have contributed to a collection of public domain software for processing and displaying SeaBeam 2000 data, much of which is being used to visualize the East Pacific Rise.<<ETX>>","PeriodicalId":130255,"journal":{"name":"Proceedings of OCEANS '93","volume":"27 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":"127771027","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 : 1993-10-18DOI: 10.1109/OCEANS.1993.326139
A. Horwitz, G. Graham, R. Kuwahara
Canada's new Maritime Coastal Defence Vessels will be the first naval ships to be fitted with a ground-breaking new Mine Countermeasures system. The system provides the capability to: acquire sonar images of the seabed with the highest combination of area coverage rate and resolution; accurately geographically position and geocode the sonar image data; store all acquired image data in a geographically keyed database; perform target detection and classification using change detection and inspect suspicious objects using a Remotely Operated Vehicle.<>
{"title":"The Canadian Maritime Coastal Defence Vessel (MCDV) and the integrated survey and inspection system","authors":"A. Horwitz, G. Graham, R. Kuwahara","doi":"10.1109/OCEANS.1993.326139","DOIUrl":"https://doi.org/10.1109/OCEANS.1993.326139","url":null,"abstract":"Canada's new Maritime Coastal Defence Vessels will be the first naval ships to be fitted with a ground-breaking new Mine Countermeasures system. The system provides the capability to: acquire sonar images of the seabed with the highest combination of area coverage rate and resolution; accurately geographically position and geocode the sonar image data; store all acquired image data in a geographically keyed database; perform target detection and classification using change detection and inspect suspicious objects using a Remotely Operated Vehicle.<<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":"133518874","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 : 1993-10-18DOI: 10.1109/OCEANS.1993.326176
K. Mitsuzawa, H. Momma, M. Fukasawa, H. Hotta
The Suruga Trough, located 150 km away to the south-east of Tokyo, Japan, is known to have turbidity and strong deep water currents. In 1989 and 1990, the authors measured the current from the bottom layer to the middle layer using moored current meters in order to understand the characteristics of the bottom current. Visual observation has been also done at the bottom using a 8 mm-video camera. The following results were obtained from the observations: i) There are steady changes of current with about 13 days cycle depending on tide. At the spring tide, current of SSW direction with a period of a day was found; maximum velocity is about 60 cm/sec. At the neap tide, the current is below 20 cm/sec with a period of a half day. 2) A turbidity current in the deep sea area caused by a typhoon was observed at the bottom layer in August 1990. The maximum velocity was over 70 m/sec. 3) Sediment transport processes associated with the bottom current was observed by the video images.<>
{"title":"Observation of deep sea current and change of bottom shapes in the Suruga Trough","authors":"K. Mitsuzawa, H. Momma, M. Fukasawa, H. Hotta","doi":"10.1109/OCEANS.1993.326176","DOIUrl":"https://doi.org/10.1109/OCEANS.1993.326176","url":null,"abstract":"The Suruga Trough, located 150 km away to the south-east of Tokyo, Japan, is known to have turbidity and strong deep water currents. In 1989 and 1990, the authors measured the current from the bottom layer to the middle layer using moored current meters in order to understand the characteristics of the bottom current. Visual observation has been also done at the bottom using a 8 mm-video camera. The following results were obtained from the observations: i) There are steady changes of current with about 13 days cycle depending on tide. At the spring tide, current of SSW direction with a period of a day was found; maximum velocity is about 60 cm/sec. At the neap tide, the current is below 20 cm/sec with a period of a half day. 2) A turbidity current in the deep sea area caused by a typhoon was observed at the bottom layer in August 1990. The maximum velocity was over 70 m/sec. 3) Sediment transport processes associated with the bottom current was observed by the video images.<<ETX>>","PeriodicalId":130255,"journal":{"name":"Proceedings of OCEANS '93","volume":"67 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":"131887541","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 : 1993-10-18DOI: 10.1109/OCEANS.1993.326231
J. Wiskin, S. A. Johnson, D. Borup, M. Berggren, R. Eidens
This Oceans 93 paper describes full nonlinear inversion that gives quantitative reconstructions of submerged and/or buried objects with the aid of a layered Greens function. The computational speed is preserved by use of Fast Fourier Transforms and stabilized biconjugate gradients, for both the homogeneous background and layered background case.<>
{"title":"Full inverse scattering vs. Born-like approximation for imaging in a stratified ocean","authors":"J. Wiskin, S. A. Johnson, D. Borup, M. Berggren, R. Eidens","doi":"10.1109/OCEANS.1993.326231","DOIUrl":"https://doi.org/10.1109/OCEANS.1993.326231","url":null,"abstract":"This Oceans 93 paper describes full nonlinear inversion that gives quantitative reconstructions of submerged and/or buried objects with the aid of a layered Greens function. The computational speed is preserved by use of Fast Fourier Transforms and stabilized biconjugate gradients, for both the homogeneous background and layered background case.<<ETX>>","PeriodicalId":130255,"journal":{"name":"Proceedings of OCEANS '93","volume":"105 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":"133100706","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 : 1993-10-18DOI: 10.1109/OCEANS.1993.326201
D. W. Craig
Previous experimental measurements of beam noise have shown that spectrum levels measured with towed line arrays have considerable temporal and spatial variability. In the ambient noise region dominated by shipping noise (a few Hz to a few hundred Hz), variations in spectral levels of over 30 dB can occur. Attempts to model the predicted beam noise cumulative distribution function (R.M. Heitmeyer, L.T. Davis and N. Yen, NRL Report 8863, February 1985) required approximations for both the beam pattern and transmission loss to achieve an analytic solution. The computed detection gain in regions of reduced noise resulting from resolution of individual noise-interferers, termed "ship resolution gain" (SRG), is dependent on source distribution, acoustic transmission loss and beam pattern approximation. The paper uses numerical computation of SRG to treat arbitrary hydrophone shading and realistic ocean environments. Results are compared to earlier analytic predictions to show dependence on system and environmental parameters.<>
{"title":"Computing ship resolution gain for horizontal towed arrays in realistic ocean environments","authors":"D. W. Craig","doi":"10.1109/OCEANS.1993.326201","DOIUrl":"https://doi.org/10.1109/OCEANS.1993.326201","url":null,"abstract":"Previous experimental measurements of beam noise have shown that spectrum levels measured with towed line arrays have considerable temporal and spatial variability. In the ambient noise region dominated by shipping noise (a few Hz to a few hundred Hz), variations in spectral levels of over 30 dB can occur. Attempts to model the predicted beam noise cumulative distribution function (R.M. Heitmeyer, L.T. Davis and N. Yen, NRL Report 8863, February 1985) required approximations for both the beam pattern and transmission loss to achieve an analytic solution. The computed detection gain in regions of reduced noise resulting from resolution of individual noise-interferers, termed \"ship resolution gain\" (SRG), is dependent on source distribution, acoustic transmission loss and beam pattern approximation. The paper uses numerical computation of SRG to treat arbitrary hydrophone shading and realistic ocean environments. Results are compared to earlier analytic predictions to show dependence on system and environmental parameters.<<ETX>>","PeriodicalId":130255,"journal":{"name":"Proceedings of OCEANS '93","volume":"3 8","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1993-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114023843","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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