Pub Date : 2010-05-24DOI: 10.1109/OCEANSSYD.2010.5603629
Shih-Jen Huang, N. Kuo, Chung‐Ru Ho, Cheng-Han Tsai, Hsien-Wen Li, Y. Lo, D. Doong, Hung-Jen Lee, Y. Kehr
In this study, the FORMOSAT-2 satellite data was used to estimate the bathymetry directly or through unsupervised classification first. Both the satellite retrieved water depths were corrected by the in-situ tidal data. The no-classified results show that more than 82% satellite-derived water depths have the error below 20% comparing with the in-situ data. Meanwhile, its root mean square error is 2.5 m. After classification, it is found that class 4 and 5 are located on the water region. Therefore, the retrieved water depth can be calculated just in class 4 and 5 regions. At class 4, there are 77% of data points having the error less than 20%. Its root mean square error is 2.7m. At class 5, more than 81% data points with the error below 20% and its root mean square error is 1.0m. The results indicate that the shallow water depth could be mapped accurately from FORMOSAT-2 image. Moreover, the satellite data has the potential to become an important tool for bathymetry map based on its spatial coverage, frequent interval, and safety.
{"title":"Mapping the coastal bathymetry with FORMOSAT-2 image","authors":"Shih-Jen Huang, N. Kuo, Chung‐Ru Ho, Cheng-Han Tsai, Hsien-Wen Li, Y. Lo, D. Doong, Hung-Jen Lee, Y. Kehr","doi":"10.1109/OCEANSSYD.2010.5603629","DOIUrl":"https://doi.org/10.1109/OCEANSSYD.2010.5603629","url":null,"abstract":"In this study, the FORMOSAT-2 satellite data was used to estimate the bathymetry directly or through unsupervised classification first. Both the satellite retrieved water depths were corrected by the in-situ tidal data. The no-classified results show that more than 82% satellite-derived water depths have the error below 20% comparing with the in-situ data. Meanwhile, its root mean square error is 2.5 m. After classification, it is found that class 4 and 5 are located on the water region. Therefore, the retrieved water depth can be calculated just in class 4 and 5 regions. At class 4, there are 77% of data points having the error less than 20%. Its root mean square error is 2.7m. At class 5, more than 81% data points with the error below 20% and its root mean square error is 1.0m. The results indicate that the shallow water depth could be mapped accurately from FORMOSAT-2 image. Moreover, the satellite data has the potential to become an important tool for bathymetry map based on its spatial coverage, frequent interval, and safety.","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":"122695188","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.2010.5603880
G. Llort-Pujol, C. Sintes, T. Chonavel, D. Guériot, R. Garello
Due to operational constraints for underwater data acquisition, simulating realistic sonar data, like images, swath bathymetry profiles or interferometric signals, is crucial for tuning detection and classification algorithms according to sensors settings, sea-bottom nature and topography. Moreover, the robustness of any performance estimation or prediction can be greatly enhanced, as soon as such a simulation tool provides a modular and flexible underwater world representation (multiple sensors, environments and acquisition conditions. For signal and array processing, it is essential not only to generate the signal energy backscattered by a resolution cell, but also to produce a phase information that conveys its theoretical statistical properties. To this end, this paper proposes a Brownian motion-based approach to generate complex Gaussian signals from the contribution of a set of extended single scatterers inside a resolution cell. The resulting process preserves the conservation of energy when integrating on surfaces, as well as the decorrelation between different areas of the sea bottom, and the right interference between two sensors for interferometric applications.
{"title":"Simulation on large scale of acoustic signals for array processing","authors":"G. Llort-Pujol, C. Sintes, T. Chonavel, D. Guériot, R. Garello","doi":"10.1109/OCEANSSYD.2010.5603880","DOIUrl":"https://doi.org/10.1109/OCEANSSYD.2010.5603880","url":null,"abstract":"Due to operational constraints for underwater data acquisition, simulating realistic sonar data, like images, swath bathymetry profiles or interferometric signals, is crucial for tuning detection and classification algorithms according to sensors settings, sea-bottom nature and topography. Moreover, the robustness of any performance estimation or prediction can be greatly enhanced, as soon as such a simulation tool provides a modular and flexible underwater world representation (multiple sensors, environments and acquisition conditions. For signal and array processing, it is essential not only to generate the signal energy backscattered by a resolution cell, but also to produce a phase information that conveys its theoretical statistical properties. To this end, this paper proposes a Brownian motion-based approach to generate complex Gaussian signals from the contribution of a set of extended single scatterers inside a resolution cell. The resulting process preserves the conservation of energy when integrating on surfaces, as well as the decorrelation between different areas of the sea bottom, and the right interference between two sensors for interferometric applications.","PeriodicalId":129808,"journal":{"name":"OCEANS'10 IEEE SYDNEY","volume":"153 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":"122857531","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.2010.5603511
A. Sehgal, Iyad Tumar, J. Schonwalder
Global climate change is a widely accepted phenomenon and it is well understood that it is also leading to changes in the oceanic conditions. Increased industrial activities have also led to anthropogenic ocean acidification, the effects of which, on marine ecosystems, is a vigorously investigated topic. However, the impact of these phenomenon on underwater acoustic communication has not been investigated thoroughly. Fluctuations in ambient ocean conditions, such as salinity, acidity and temperature can lead to changes in the underwater acoustic channel performance. Since both marine mammals and man-made underwater wireless networks depend upon acoustic communications it is important to understand the effects in this context as well. An insight into the effects of climate change and anthropogenic ocean acidification could aid in designing better communication systems and also help explain some observed changes in marine mammal communication behavior. In this paper we present the results of a study conducted to better understand the effects of global climate change. Along with a brief presentation of the mathematical model, results of increasing temperature and acidity are discussed and effects on digital and marine mammal communication are both explored.
{"title":"Effects of climate change and anthropogenic ocean acidification on underwater acoustic communications","authors":"A. Sehgal, Iyad Tumar, J. Schonwalder","doi":"10.1109/OCEANSSYD.2010.5603511","DOIUrl":"https://doi.org/10.1109/OCEANSSYD.2010.5603511","url":null,"abstract":"Global climate change is a widely accepted phenomenon and it is well understood that it is also leading to changes in the oceanic conditions. Increased industrial activities have also led to anthropogenic ocean acidification, the effects of which, on marine ecosystems, is a vigorously investigated topic. However, the impact of these phenomenon on underwater acoustic communication has not been investigated thoroughly. Fluctuations in ambient ocean conditions, such as salinity, acidity and temperature can lead to changes in the underwater acoustic channel performance. Since both marine mammals and man-made underwater wireless networks depend upon acoustic communications it is important to understand the effects in this context as well. An insight into the effects of climate change and anthropogenic ocean acidification could aid in designing better communication systems and also help explain some observed changes in marine mammal communication behavior. In this paper we present the results of a study conducted to better understand the effects of global climate change. Along with a brief presentation of the mathematical model, results of increasing temperature and acidity are discussed and effects on digital and marine mammal communication are both explored.","PeriodicalId":129808,"journal":{"name":"OCEANS'10 IEEE SYDNEY","volume":"113 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":"122944907","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.2010.5603577
K. T. Dharan, C. Srimathi, Soo-Hyun Park
In underwater sensor networks (UWSNs), determining the location of every sensor is important. The process of estimating the location of each node in a sensor network is known as localization. While various localization algorithms have been proposed for terrestrial sensor networks, there are relatively few localization schemes for UWSNs. Since the sensor nodes are in underwater, they are prone to a high dynamic environment due to sea waves. The position of the underwater sensor nodes keep changing due to external factors and harsh physical environment. In this paper we propose a sweeper scheme for localization of sensor nodes and also a mobility prediction scheme which helps in calculating the position of the sensor nodes at regular intervals. A key advantage of our scheme is that it can handle network Dynamics efficiently with the assistance of a localization service. Moreover, the scheme does not need a multiple-sink under water sensor network architecture for data gathering.
{"title":"A sweeper scheme for localization and mobility prediction in underwater acoustic sensor networks","authors":"K. T. Dharan, C. Srimathi, Soo-Hyun Park","doi":"10.1109/OCEANSSYD.2010.5603577","DOIUrl":"https://doi.org/10.1109/OCEANSSYD.2010.5603577","url":null,"abstract":"In underwater sensor networks (UWSNs), determining the location of every sensor is important. The process of estimating the location of each node in a sensor network is known as localization. While various localization algorithms have been proposed for terrestrial sensor networks, there are relatively few localization schemes for UWSNs. Since the sensor nodes are in underwater, they are prone to a high dynamic environment due to sea waves. The position of the underwater sensor nodes keep changing due to external factors and harsh physical environment. In this paper we propose a sweeper scheme for localization of sensor nodes and also a mobility prediction scheme which helps in calculating the position of the sensor nodes at regular intervals. A key advantage of our scheme is that it can handle network Dynamics efficiently with the assistance of a localization service. Moreover, the scheme does not need a multiple-sink under water sensor network architecture for data gathering.","PeriodicalId":129808,"journal":{"name":"OCEANS'10 IEEE SYDNEY","volume":"2 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":"121775157","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.2010.5603676
T. Kutser
The amount of CDOM in arctic waters plays an important role both from global carbon cycle point of view and from radiative heating point of view of surface waters. The first part of this paper summarizes the current situation in remote sensing mapping of CDOM concentration in Arctic Ocean. Radiative heating calculations were carried out with Hydrolight 5.0 model in order to estimate the impact of variable amount of CDOM on heating of Arctic surface waters. Also the total area where the Arctic Ocean waters differ from the clear oceanic waters was estimated using MODIS Kd(490) product.
{"title":"Global change and remote sensing of CDOM in Arctic coastal waters","authors":"T. Kutser","doi":"10.1109/OCEANSSYD.2010.5603676","DOIUrl":"https://doi.org/10.1109/OCEANSSYD.2010.5603676","url":null,"abstract":"The amount of CDOM in arctic waters plays an important role both from global carbon cycle point of view and from radiative heating point of view of surface waters. The first part of this paper summarizes the current situation in remote sensing mapping of CDOM concentration in Arctic Ocean. Radiative heating calculations were carried out with Hydrolight 5.0 model in order to estimate the impact of variable amount of CDOM on heating of Arctic surface waters. Also the total area where the Arctic Ocean waters differ from the clear oceanic waters was estimated using MODIS Kd(490) product.","PeriodicalId":129808,"journal":{"name":"OCEANS'10 IEEE SYDNEY","volume":"47 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":"127593034","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.2010.5603802
A. Joseph, R. G. Prabhudesai, P. Mehra, Vijay Kumar, Y. Agarwadekar, L. Ryan, Pradhan Rivankar, Blossom Viegas
Spatial and temporal response of the coastal waters of eastern Arabian Sea (AS) and Kavaratti lagoon to the tropical cyclonic storm ‘Phyan’, which developed in the southeastern AS and swept northward along the eastern AS during 9–12 November 2009 and finally made landfall at the northwest coast of India, is examined based on time-series measurements of sea-surface wind (U10), gust, gust factor, barometric pressure, precipitation, atmospheric temperature, SST, and significant wave height from satellite-derived and in-situ measurements. The maximum wind-speed (U10) of ∼16 m/s occurred at Kavaratti Island region followed by ∼8 m/s at Dwarka in Gujarat, where the cyclone landfall occurred, and ∼7 m/s at Diu located just south of Dwarka as well as two southwest Indian coastal locations at Mangalore and Malpe. All other west India coastal locations recorded maximum wind speed of ∼5–6 m/s. Gust factor during peak storm event was highly variable with respect to topography, with steep hilly stations and proximate thick and tall vegetation exhibiting the largest value whereas coastal planes and Island stations exhibiting the least. Rainfall in association with Phyan was temporally scattered, with the highest 24-h accumulated precipitation (∼60 mm) at Karwar and ∼45 mm at several other locations. Impact of Phyan on the west India coastal waters was manifested in terms of intensified significant wave height (∼3 m at Karwar, Panaji, and Ratnagiri), sea surface cooling (∼5°C at Calicut), and surge flooding (∼80 cm at Verem). Several factors such as (i) water piling up at the coast supported by seaward flow of the excess water in the rivers due to heavy rains and westerly cross-shore wind, (ii) water piling down at the coast supported by the northerly alongshore wind (by virtue of Coriolis effect) and upstream penetration of seawater into the rivers, and (iii) possible interaction of upstream flow with river runoff, together resulted in the observed surge flooding at the west India coast. Despite the intense wind forcing, Kavaratti Island lagoon experienced insignificantly weak surge (∼7 cm) because of lack of river influx and absence of a sufficiently large land boundary required for the sustenance of wave/wind-driven water mass which tends to pile up at the land-sea interface.
{"title":"November 2009 tropical cyclone Phyan in the eastern Arabian Sea: Oceanic response along west India coast and Kavaratti lagoon","authors":"A. Joseph, R. G. Prabhudesai, P. Mehra, Vijay Kumar, Y. Agarwadekar, L. Ryan, Pradhan Rivankar, Blossom Viegas","doi":"10.1109/OCEANSSYD.2010.5603802","DOIUrl":"https://doi.org/10.1109/OCEANSSYD.2010.5603802","url":null,"abstract":"Spatial and temporal response of the coastal waters of eastern Arabian Sea (AS) and Kavaratti lagoon to the tropical cyclonic storm ‘Phyan’, which developed in the southeastern AS and swept northward along the eastern AS during 9–12 November 2009 and finally made landfall at the northwest coast of India, is examined based on time-series measurements of sea-surface wind (U10), gust, gust factor, barometric pressure, precipitation, atmospheric temperature, SST, and significant wave height from satellite-derived and in-situ measurements. The maximum wind-speed (U10) of ∼16 m/s occurred at Kavaratti Island region followed by ∼8 m/s at Dwarka in Gujarat, where the cyclone landfall occurred, and ∼7 m/s at Diu located just south of Dwarka as well as two southwest Indian coastal locations at Mangalore and Malpe. All other west India coastal locations recorded maximum wind speed of ∼5–6 m/s. Gust factor during peak storm event was highly variable with respect to topography, with steep hilly stations and proximate thick and tall vegetation exhibiting the largest value whereas coastal planes and Island stations exhibiting the least. Rainfall in association with Phyan was temporally scattered, with the highest 24-h accumulated precipitation (∼60 mm) at Karwar and ∼45 mm at several other locations. Impact of Phyan on the west India coastal waters was manifested in terms of intensified significant wave height (∼3 m at Karwar, Panaji, and Ratnagiri), sea surface cooling (∼5°C at Calicut), and surge flooding (∼80 cm at Verem). Several factors such as (i) water piling up at the coast supported by seaward flow of the excess water in the rivers due to heavy rains and westerly cross-shore wind, (ii) water piling down at the coast supported by the northerly alongshore wind (by virtue of Coriolis effect) and upstream penetration of seawater into the rivers, and (iii) possible interaction of upstream flow with river runoff, together resulted in the observed surge flooding at the west India coast. Despite the intense wind forcing, Kavaratti Island lagoon experienced insignificantly weak surge (∼7 cm) because of lack of river influx and absence of a sufficiently large land boundary required for the sustenance of wave/wind-driven water mass which tends to pile up at the land-sea interface.","PeriodicalId":129808,"journal":{"name":"OCEANS'10 IEEE SYDNEY","volume":"71 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":"132529370","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.2010.5603813
Z. Ismail, M. Dunnigan
In this paper, a sub-region tracking control scheme is proposed for an Underwater Vehicle-Manipulator System (UVMS). In the proposed controller, the desired primary task of the UVMS is specified as two sub-regions that are assigned for the vehicle and end-effector. The unit quaternion representation is utilized to achieve singularity-free attitude tracking control. In addition, due to the kinematically redundant system, the controller also enables the use of self motion of the system to perform sub-tasks (drag minimization, obstacle avoidance, manipulability and avoidance of mechanical joint limits). Despite the parametric uncertainty associated with the underwater dynamic model, the controller ensures the sub-task tracking without affecting the sub-region and attitude tracking control objective. The controller has been designed based on a Lyapunov type approach. Results from simulations are presented to demonstrate the benefits of the proposed control law.
{"title":"A sub-region tracking control for an Underwater Vehicle-Manipulator System with a sub-task objective","authors":"Z. Ismail, M. Dunnigan","doi":"10.1109/OCEANSSYD.2010.5603813","DOIUrl":"https://doi.org/10.1109/OCEANSSYD.2010.5603813","url":null,"abstract":"In this paper, a sub-region tracking control scheme is proposed for an Underwater Vehicle-Manipulator System (UVMS). In the proposed controller, the desired primary task of the UVMS is specified as two sub-regions that are assigned for the vehicle and end-effector. The unit quaternion representation is utilized to achieve singularity-free attitude tracking control. In addition, due to the kinematically redundant system, the controller also enables the use of self motion of the system to perform sub-tasks (drag minimization, obstacle avoidance, manipulability and avoidance of mechanical joint limits). Despite the parametric uncertainty associated with the underwater dynamic model, the controller ensures the sub-task tracking without affecting the sub-region and attitude tracking control objective. The controller has been designed based on a Lyapunov type approach. Results from simulations are presented to demonstrate the benefits of the proposed control law.","PeriodicalId":129808,"journal":{"name":"OCEANS'10 IEEE SYDNEY","volume":"73 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":"132777894","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.2010.5603825
N. Chotiros, M. Isakson
Calcarenite is described as sand-size particles that are cemented together by carbonates, therefore it should be modeled as a poroelastic medium. Elastic and poroelastic models of calcarenite are compared. The poroelastic models include the baseline Biot model and the Biot-Stoll with contact squirt flow and viscous shear drag (BICSQS) model. Input parameters for the poroelastic models are developed. Reflection loss as a function of frequency and angle is computed. Model predictions of shallow water propagation loss over a calcarenite seabed are compared. Differences in propagation loss predictions are discussed.
{"title":"Calcarenite as a poroelastic granular medium","authors":"N. Chotiros, M. Isakson","doi":"10.1109/OCEANSSYD.2010.5603825","DOIUrl":"https://doi.org/10.1109/OCEANSSYD.2010.5603825","url":null,"abstract":"Calcarenite is described as sand-size particles that are cemented together by carbonates, therefore it should be modeled as a poroelastic medium. Elastic and poroelastic models of calcarenite are compared. The poroelastic models include the baseline Biot model and the Biot-Stoll with contact squirt flow and viscous shear drag (BICSQS) model. Input parameters for the poroelastic models are developed. Reflection loss as a function of frequency and angle is computed. Model predictions of shallow water propagation loss over a calcarenite seabed are compared. Differences in propagation loss predictions are discussed.","PeriodicalId":129808,"journal":{"name":"OCEANS'10 IEEE SYDNEY","volume":"32 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":"133420434","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.2010.5603806
Y. Kyozuka, Yusufumi Uchida, Ayano Kudoh, Shigeyoshi Kawaguchi
Hakata Bay is an enclosed bay adjacent to Fukuoka City and the eutrophication of the bay water has been getting serious by the sewage contamination in recent years. In this study, we propose a plan to improve the water quality by making use of the underground water upwelling by plunged pipes into the bottom of the bay. The density of the underground water is smaller than sea water that the vertical circulation and the upwelling of the bottom water by the entrainment effects will be generated in the bay, which may improve the water quality of the bay. Field measurement results of the water quality and the quantity of the underground water together with the laboratory experiments and numerical simulations of the diffusion of the underground water in the bay are presented in this paper.
{"title":"A feasibility study on the water quality improvement by making use of underground water in Hakata Bay","authors":"Y. Kyozuka, Yusufumi Uchida, Ayano Kudoh, Shigeyoshi Kawaguchi","doi":"10.1109/OCEANSSYD.2010.5603806","DOIUrl":"https://doi.org/10.1109/OCEANSSYD.2010.5603806","url":null,"abstract":"Hakata Bay is an enclosed bay adjacent to Fukuoka City and the eutrophication of the bay water has been getting serious by the sewage contamination in recent years. In this study, we propose a plan to improve the water quality by making use of the underground water upwelling by plunged pipes into the bottom of the bay. The density of the underground water is smaller than sea water that the vertical circulation and the upwelling of the bottom water by the entrainment effects will be generated in the bay, which may improve the water quality of the bay. Field measurement results of the water quality and the quantity of the underground water together with the laboratory experiments and numerical simulations of the diffusion of the underground water in the bay are presented in this paper.","PeriodicalId":129808,"journal":{"name":"OCEANS'10 IEEE SYDNEY","volume":"26 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":"131833522","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.2010.5603992
Marcelo Borges Nogueira, J. Sousa, F. Pereira
Due to some communication constraints of the underwater environment, cooperative localization for AUVs is a hard task. In this paper, we present the state of the art in this area, analyse the existing solutions to related problems and propose 2 algorithms, based on the EKF, to solve the localization problem with a group of Autonomous Underwater Vehicles equipped with low cost navigation systems in an unknown environment. Without the aid of a global positioning system, the navigation error will grow unbounded. However, navigation performance can be greatly improved with our cooperative navigation scheme, as shown in simulations. We also show that the methods give better results when compared to an existing solution and perform a nonlinear observability analysis of the system to show the boundedness of the error with the aid of a global positioning system.
{"title":"Cooperative Autonomous Underwater Vehicle localization","authors":"Marcelo Borges Nogueira, J. Sousa, F. Pereira","doi":"10.1109/OCEANSSYD.2010.5603992","DOIUrl":"https://doi.org/10.1109/OCEANSSYD.2010.5603992","url":null,"abstract":"Due to some communication constraints of the underwater environment, cooperative localization for AUVs is a hard task. In this paper, we present the state of the art in this area, analyse the existing solutions to related problems and propose 2 algorithms, based on the EKF, to solve the localization problem with a group of Autonomous Underwater Vehicles equipped with low cost navigation systems in an unknown environment. Without the aid of a global positioning system, the navigation error will grow unbounded. However, navigation performance can be greatly improved with our cooperative navigation scheme, as shown in simulations. We also show that the methods give better results when compared to an existing solution and perform a nonlinear observability analysis of the system to show the boundedness of the error with the aid of a global positioning system.","PeriodicalId":129808,"journal":{"name":"OCEANS'10 IEEE SYDNEY","volume":"35 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":"132223397","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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