Pub Date : 2010-05-24DOI: 10.1109/OCEANSSYD.2010.5603631
A. Blomberg, M. Hayes
In this paper we consider adaptive beamforming techniques to suppress the dominant multipath for a multielement interferometric synthetic aperture sonar. We use a broadband variant of the minimum variance (MV) beamformer and apply it to reconstruct bathymetry using data from the KiwiSAS-4 sonar. This has three vertically displaced hydrophone arrays. The MV beamformer is used to estimate the angle of arrival of the backscattered echo from the sea floor, and from that the height of the sea floor. The conventional delay-and-sum (DAS) beamformer is used for comparison.
{"title":"Multipath reduction for bathymetry using adaptive beamforming","authors":"A. Blomberg, M. Hayes","doi":"10.1109/OCEANSSYD.2010.5603631","DOIUrl":"https://doi.org/10.1109/OCEANSSYD.2010.5603631","url":null,"abstract":"In this paper we consider adaptive beamforming techniques to suppress the dominant multipath for a multielement interferometric synthetic aperture sonar. We use a broadband variant of the minimum variance (MV) beamformer and apply it to reconstruct bathymetry using data from the KiwiSAS-4 sonar. This has three vertically displaced hydrophone arrays. The MV beamformer is used to estimate the angle of arrival of the backscattered echo from the sea floor, and from that the height of the sea floor. The conventional delay-and-sum (DAS) beamformer is used for comparison.","PeriodicalId":129808,"journal":{"name":"OCEANS'10 IEEE SYDNEY","volume":"63 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-05-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122882356","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 : 2010-05-24DOI: 10.1109/OCEANSSYD.2010.5603659
Rikito Hisamatsu, S. Tabeta
In order to assess the effect of environmental restoration plans for a small scale beach called Heda-Mihama, simulation-based habitat evaluation approach is employed. A three-dimensional hydrodynamic model is developed by using the measured topography to reproduce the characteristics of currents around Heda-Mihama. A sediment transport model is also developed to predict the distribution and change of sediment size at the target site. For the assessment of the ecological value of the site, HEP (Habitat Evaluation Procedure) is employed, in which one of the typical species of bivalves is chosen as a target species. Water depth, sediment size, bottom friction velocity are chosen as the environmental factors for the target species. The suitable indices (SI) for each environmental factors are calculated by using the results of hydrodynamic and sediment transport simulations. By using the developed scheme, habitat values are evaluated for the proposed restoration plans and compared to the current values. It is predicted that the removal of the piers will significantly increase the habitat value of the target site. It is because the water current is significantly increased which make the sediment size larger as well as promote the water exchange at the site.
{"title":"Assessment of environmental restoration plans for a small-scale beach by simulation-based habitat evaluation","authors":"Rikito Hisamatsu, S. Tabeta","doi":"10.1109/OCEANSSYD.2010.5603659","DOIUrl":"https://doi.org/10.1109/OCEANSSYD.2010.5603659","url":null,"abstract":"In order to assess the effect of environmental restoration plans for a small scale beach called Heda-Mihama, simulation-based habitat evaluation approach is employed. A three-dimensional hydrodynamic model is developed by using the measured topography to reproduce the characteristics of currents around Heda-Mihama. A sediment transport model is also developed to predict the distribution and change of sediment size at the target site. For the assessment of the ecological value of the site, HEP (Habitat Evaluation Procedure) is employed, in which one of the typical species of bivalves is chosen as a target species. Water depth, sediment size, bottom friction velocity are chosen as the environmental factors for the target species. The suitable indices (SI) for each environmental factors are calculated by using the results of hydrodynamic and sediment transport simulations. By using the developed scheme, habitat values are evaluated for the proposed restoration plans and compared to the current values. It is predicted that the removal of the piers will significantly increase the habitat value of the target site. It is because the water current is significantly increased which make the sediment size larger as well as promote the water exchange at the site.","PeriodicalId":129808,"journal":{"name":"OCEANS'10 IEEE SYDNEY","volume":"116 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-05-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124016768","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 : 2010-05-24DOI: 10.1109/OCEANSSYD.2010.5603878
K. Asakawa, Makoto Ito, T. Hyakudome
We have designed and produced small models of ceramic pressure housings for use in a free-fall floating ocean-bottom seismometer that is useful at up to 11,000 m water depth. We also present a new design method of plural through-holes for underwater connectors on ceramic hemispheres. Its design concept and the results of finite element analysis (FEA) are presented along with results of hydraulic pressure tests using 1/4-scale models. Actual-size ceramic pressure housing will be completed soon.
{"title":"Evaluation of small models of ceramic housings for 11,000 m ocean bottom seismometers","authors":"K. Asakawa, Makoto Ito, T. Hyakudome","doi":"10.1109/OCEANSSYD.2010.5603878","DOIUrl":"https://doi.org/10.1109/OCEANSSYD.2010.5603878","url":null,"abstract":"We have designed and produced small models of ceramic pressure housings for use in a free-fall floating ocean-bottom seismometer that is useful at up to 11,000 m water depth. We also present a new design method of plural through-holes for underwater connectors on ceramic hemispheres. Its design concept and the results of finite element analysis (FEA) are presented along with results of hydraulic pressure tests using 1/4-scale models. Actual-size ceramic pressure housing will be completed soon.","PeriodicalId":129808,"journal":{"name":"OCEANS'10 IEEE SYDNEY","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-05-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124191141","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 : 2010-05-24DOI: 10.1109/OCEANSSYD.2010.5603850
M. Sangekar, B. Thornton, T. Nakatani, T. Ura
The autonomous underwater vehicle has proven to be a useful tool for ocean research. However detailed seafloor observations such as microscopic analysis of sand grain structure or study of microbial colonies require a platform with stable footing on the seafloor, which cannot be provided by a cruising type AUV. In this research the authors propose a new class of AUV, capable of landing to provide a stable, but mobile, platform with which to perform these observations. This paper proposes a sensing system and a software algorithm to enable the AUVs to perform landing. A light sectioning based method is used to scan the seafloor with high resolution. Since the seafloor can change abruptly and at short intervals, the reliability and functioning of such technology requires real-time seafloor classification and detection of suitable landing sites. A landing algorithm has been developed which uses three dimensional bathymetry data and calculates a landing vector coordinate in real-time. A microscope sensor payload developed to obtain magnified images of the seafloor after landing has also been tested. Data from sea experiments are presented, where the algorithm demonstrated real-time generation of landing vector coordinates for an ROV.
{"title":"Development of a landing algorithm for autonomous underwater vehicles using laser profiling","authors":"M. Sangekar, B. Thornton, T. Nakatani, T. Ura","doi":"10.1109/OCEANSSYD.2010.5603850","DOIUrl":"https://doi.org/10.1109/OCEANSSYD.2010.5603850","url":null,"abstract":"The autonomous underwater vehicle has proven to be a useful tool for ocean research. However detailed seafloor observations such as microscopic analysis of sand grain structure or study of microbial colonies require a platform with stable footing on the seafloor, which cannot be provided by a cruising type AUV. In this research the authors propose a new class of AUV, capable of landing to provide a stable, but mobile, platform with which to perform these observations. This paper proposes a sensing system and a software algorithm to enable the AUVs to perform landing. A light sectioning based method is used to scan the seafloor with high resolution. Since the seafloor can change abruptly and at short intervals, the reliability and functioning of such technology requires real-time seafloor classification and detection of suitable landing sites. A landing algorithm has been developed which uses three dimensional bathymetry data and calculates a landing vector coordinate in real-time. A microscope sensor payload developed to obtain magnified images of the seafloor after landing has also been tested. Data from sea experiments are presented, where the algorithm demonstrated real-time generation of landing vector coordinates for an ROV.","PeriodicalId":129808,"journal":{"name":"OCEANS'10 IEEE SYDNEY","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-05-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129853558","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 : 2010-05-24DOI: 10.1109/OCEANSSYD.2010.5603585
J. Young, S. Keenan, D. Clark, P. Sullivan, S. Billings
We are developing a magnetic tensor gradiometer for underwater unexploded ordnance (UXO) detection using high-Tc SQUID planar gradiometers. The system will use signals from six planar gradiometers, located on the faces of a hexagonal pyramid, to calculate the full gradient tensor. It will be towed underwater and will need to deal with noise caused by ocean waves, sensor motion and the measurement capsule itself. This paper presents our progress to date on this project including test results of gradiometer performance in laboratory conditions.
{"title":"Development of a high temperature superconducting magnetic tensor gradiometer for underwater UXO detection","authors":"J. Young, S. Keenan, D. Clark, P. Sullivan, S. Billings","doi":"10.1109/OCEANSSYD.2010.5603585","DOIUrl":"https://doi.org/10.1109/OCEANSSYD.2010.5603585","url":null,"abstract":"We are developing a magnetic tensor gradiometer for underwater unexploded ordnance (UXO) detection using high-Tc SQUID planar gradiometers. The system will use signals from six planar gradiometers, located on the faces of a hexagonal pyramid, to calculate the full gradient tensor. It will be towed underwater and will need to deal with noise caused by ocean waves, sensor motion and the measurement capsule itself. This paper presents our progress to date on this project including test results of gradiometer performance in laboratory conditions.","PeriodicalId":129808,"journal":{"name":"OCEANS'10 IEEE SYDNEY","volume":"48 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-05-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129613253","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 : 2010-05-24DOI: 10.1109/OCEANSSYD.2010.5603872
M. Heron, P. Marrone
A direct measure from the spectra of HF radar sea echoes is the ratio of energy in the dominant Bragg peaks. If a single lobe is assumed for the directionality then two radar stations can be used to provide a closed solution for the direction of the lobe. In this work we examine the potential of using just one radar station to derive directional information about wind fields. It is shown that HF radar Bragg ratios are effective in providing timing and location information for features appearing on Mean Sea Level synoptic charts.
{"title":"Wind direction manifestation on HF ocean radar echoes","authors":"M. Heron, P. Marrone","doi":"10.1109/OCEANSSYD.2010.5603872","DOIUrl":"https://doi.org/10.1109/OCEANSSYD.2010.5603872","url":null,"abstract":"A direct measure from the spectra of HF radar sea echoes is the ratio of energy in the dominant Bragg peaks. If a single lobe is assumed for the directionality then two radar stations can be used to provide a closed solution for the direction of the lobe. In this work we examine the potential of using just one radar station to derive directional information about wind fields. It is shown that HF radar Bragg ratios are effective in providing timing and location information for features appearing on Mean Sea Level synoptic charts.","PeriodicalId":129808,"journal":{"name":"OCEANS'10 IEEE SYDNEY","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-05-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130950270","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 : 2010-05-24DOI: 10.1109/OCEANSSYD.2010.5603620
T. Pfuetzenreuter, Helge Renkewitz
Today a large number of autonomous underwater vehicles (AUVs) are evaluated or operated all over the world. Most of them use their own control systems created by the vehicle's manufacturer or scientists of different research areas. The Fraunhofer Application Center System Technology currently owns three underwater vehicles (both AUVs and remotely operated vehicles, ROVs), a forth is under development. All these vehicles have their individual control systems that are very different with respect to changing / creating software modules, mission planning and evaluation. These differences are one reason to develop a new software framework for underwater vehicles called ConSys.
{"title":"ConSys - a new software framework for underwater vehicles","authors":"T. Pfuetzenreuter, Helge Renkewitz","doi":"10.1109/OCEANSSYD.2010.5603620","DOIUrl":"https://doi.org/10.1109/OCEANSSYD.2010.5603620","url":null,"abstract":"Today a large number of autonomous underwater vehicles (AUVs) are evaluated or operated all over the world. Most of them use their own control systems created by the vehicle's manufacturer or scientists of different research areas. The Fraunhofer Application Center System Technology currently owns three underwater vehicles (both AUVs and remotely operated vehicles, ROVs), a forth is under development. All these vehicles have their individual control systems that are very different with respect to changing / creating software modules, mission planning and evaluation. These differences are one reason to develop a new software framework for underwater vehicles called ConSys.","PeriodicalId":129808,"journal":{"name":"OCEANS'10 IEEE SYDNEY","volume":"46 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-05-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131502538","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 : 2010-05-24DOI: 10.1109/OCEANSSYD.2010.5603592
Xiubin Qi, Emma Crooke, A. Ross
Hydrocarbon seeps in the marine environment are used as proxies for subsurface accumulations. Typically marine surveys to delineate these subsea features us a verity of techniques, which generally do not allow timely chemical identification of hydrocarbons. This paper outlines current research on the development of an integrated underway arrayed hydrocarbon sensing system that can be used on a variety of vessels to detect seeped hydrocarbons. The aim of the research is to increase the number of successful surveys through the deployment of this equipment. Field trials of the system have demonstrated its successful operation in the marine environment and testing of the hydrocarbon sensors have shown that the majority of the sensors used can detect dissolved hydrocarbons at ppb levels. Laboratory experiments using 23 oil-in-synthetic sea water extracts has shown that the sensor array has the potential to differentiate between oils (refined and unrefined) from different sources, based upon their seawater extracts.
{"title":"Development of an arrayed hydrocarbon sensing system for the detection of seeped hydrocarbons","authors":"Xiubin Qi, Emma Crooke, A. Ross","doi":"10.1109/OCEANSSYD.2010.5603592","DOIUrl":"https://doi.org/10.1109/OCEANSSYD.2010.5603592","url":null,"abstract":"Hydrocarbon seeps in the marine environment are used as proxies for subsurface accumulations. Typically marine surveys to delineate these subsea features us a verity of techniques, which generally do not allow timely chemical identification of hydrocarbons. This paper outlines current research on the development of an integrated underway arrayed hydrocarbon sensing system that can be used on a variety of vessels to detect seeped hydrocarbons. The aim of the research is to increase the number of successful surveys through the deployment of this equipment. Field trials of the system have demonstrated its successful operation in the marine environment and testing of the hydrocarbon sensors have shown that the majority of the sensors used can detect dissolved hydrocarbons at ppb levels. Laboratory experiments using 23 oil-in-synthetic sea water extracts has shown that the sensor array has the potential to differentiate between oils (refined and unrefined) from different sources, based upon their seawater extracts.","PeriodicalId":129808,"journal":{"name":"OCEANS'10 IEEE SYDNEY","volume":"55 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-05-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129890208","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 : 2010-05-24DOI: 10.1109/OCEANSSYD.2010.5603857
J. Vitorino, S. Larangeiro, Francisco Silva, J. Pinto, S. Almeida
We describe the development of an operational forecast system for the NAzare Canyon area (W Portugal) which is presently being conducted at Instituto Hidrografico (IHPT). The system integrates a number of numerical models aimed to simulate and forecasts the wave conditions, the circulation promoted in the canyon area by wind forcing, interactions with the deep sea circulation or tides, and the littoral processes. The forecast system is planned to make an extensive use of the real-time observations collected by multi-parametric platforms maintained by IH in the Nazare Canyon area as part being developed sic guidelines for preparing papers for conference proceedings.
{"title":"An operational system for the forecasting of oceanographic conditions in the Nazare Canyon area (W Portugal)","authors":"J. Vitorino, S. Larangeiro, Francisco Silva, J. Pinto, S. Almeida","doi":"10.1109/OCEANSSYD.2010.5603857","DOIUrl":"https://doi.org/10.1109/OCEANSSYD.2010.5603857","url":null,"abstract":"We describe the development of an operational forecast system for the NAzare Canyon area (W Portugal) which is presently being conducted at Instituto Hidrografico (IHPT). The system integrates a number of numerical models aimed to simulate and forecasts the wave conditions, the circulation promoted in the canyon area by wind forcing, interactions with the deep sea circulation or tides, and the littoral processes. The forecast system is planned to make an extensive use of the real-time observations collected by multi-parametric platforms maintained by IH in the Nazare Canyon area as part being developed sic guidelines for preparing papers for conference proceedings.","PeriodicalId":129808,"journal":{"name":"OCEANS'10 IEEE SYDNEY","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-05-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121974326","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 : 2010-05-24DOI: 10.1109/OCEANSSYD.2010.5603803
S. Sagar, M. Wettle
Mapping the shallow water bathymetry of aquatic environments such as the Great Barrier Reef presents a number of challenges, due to both the large area which it occupies and the widely dispersed and variable shallow water reef areas which characterize it.
{"title":"Mapping the fine-scale shallow water bathymetry of the Great Barrier Reef using ALOS AVNIR-2 data","authors":"S. Sagar, M. Wettle","doi":"10.1109/OCEANSSYD.2010.5603803","DOIUrl":"https://doi.org/10.1109/OCEANSSYD.2010.5603803","url":null,"abstract":"Mapping the shallow water bathymetry of aquatic environments such as the Great Barrier Reef presents a number of challenges, due to both the large area which it occupies and the widely dispersed and variable shallow water reef areas which characterize it.","PeriodicalId":129808,"journal":{"name":"OCEANS'10 IEEE SYDNEY","volume":"143 10","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-05-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120981710","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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