Europe Oceans 2005最新文献

{"title":"Real time sperm whale depth estimation using passive acoustics","authors":"C. Laplanche, O. Adam, M. Lopatka, J. Motsch","doi":"10.1109/OCEANSE.2005.1511698","DOIUrl":"https://doi.org/10.1109/OCEANSE.2005.1511698","url":null,"abstract":"Sperm whales (Physeter macrocephalus) make series of transient echolocation sounds (clicks), when foraging. Clicks reflect to the sea surface and the seafloor when propagating towards a receiver. The detection of the once reflected surface and seafloor echoes of a click, and the measurement of the delays of both echoes to the direct path transmitted signal, make possible the localization in depth and in range of the sperm whale which emitted the click, by using a single receiver. Repeating this process click after click then leads to the plotting of the whale depth/range variations while diving. The main difficulty when automating this process is usually to correctly identify direct path signals and echoes. The authors compute the a priori probability density functions of both surface/floor echo delays, improving this click echo identification process. The authors then use an adaptive filter, detecting simultaneously direct path signals with surface echoes. A visual estimation of the range of the whale when starting a dive is used to initiate the detection process. The detection of seafloor echoes then leads to the depth/range estimation of the whale while diving. The detection process works fine (84%, considering a 45-minute dive recording) assuming that a single sperm whale is clicking. The localization process works correctly when seafloor echoes are detected. This method is non-invasive, as it uses neither tags nor active acoustics, and easy to set, as requiring a single hydrophone and a CTD meter, and makes possible an unbiased, inexpensive, automated survey of the diving behavior of single sperm whales in a given area.","PeriodicalId":120840,"journal":{"name":"Europe Oceans 2005","volume":"77 1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132913656","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Unsupervised registration of textured images: applications to side-scan sonar","authors":"P. Mignotte, M. Lianantonakis, Y. Pétillot","doi":"10.1109/OCEANSE.2005.1511786","DOIUrl":"https://doi.org/10.1109/OCEANSE.2005.1511786","url":null,"abstract":"Sonar images are highly textured images and therefore mislead most of the classical registration algorithms. Registration is a critical step for the creation of high-resolution accurate mosaic images of the seafloor required for seabed analysis and classification. In the past concurrent mapping and localisation have successfully been used but the detection and association of landmarks have been proved difficult and been done manually. However, such methods are time consuming and lack robustness. Landmarks are not regularly present in the images and their localisation is prone to errors. As a consequence, global methods using whole images are preferable. These methods were extensively studied in the recent years and successfully applied to multimodal medical image registration. Unfortunately, the similarity metric between images they rely upon cannot cope with highly textured images. To overcome this issue, textural features must be extracted to highlight similar regions of the images. Registration of these feature maps works but remains sensible to the feature selection and their relation from one modality to the other. An alternative approach is proposed in this paper. Mutual information is calculated from all the features and global registration can be achieved directly. Solely an approximation of MI can be obtained but the performance of this algorithm are equivalent to exact approach and robust to feature selection. This method has been successfully applied to textured images (side-scan sonar) but is also applicable to multimodal images such as bathymetric and sonar data.","PeriodicalId":120840,"journal":{"name":"Europe Oceans 2005","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133614598","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Remote data access through Ethernet. Virtual instrument for oceanographic instrumentation supervision and analysis","authors":"A. Lázaro, J. del Río, S. Shariat","doi":"10.1109/OCEANSE.2005.1511756","DOIUrl":"https://doi.org/10.1109/OCEANSE.2005.1511756","url":null,"abstract":"During the last years a new class of multipurpose research vessels has been built These ships are equipped with a complete set of oceanographic, analysis and geophysical instrumentation, multibeam echosounders, parametric profilers, ADCPs, cold laboratories, and chemical analysis instrumentation (discrete and continuous). Most of these ships are working on remote areas from their bases as far as Antarctica or the Indian Ocean and there has been some initiatives to use the long transit tracks to these areas to collect useful data. Of course this data collection should be supervised not only for the quality of the data (ODAS, J. Sorribas et al. (1998)) but also the status of the equipment and the conditions of the rooms and labs where they are installed (i.e. temperature in cold chambers, pressure, etc.). In this paper we present a prototype of a system that enables the technician to supervise the equipment installed on board from a control room.","PeriodicalId":120840,"journal":{"name":"Europe Oceans 2005","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134405230","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Circular synthetic aperture sonar design","authors":"A. D. Friedman, S. K. Mitchell, T. Kooij, K. Scarbrough","doi":"10.1109/OCEANSE.2005.1513201","DOIUrl":"https://doi.org/10.1109/OCEANSE.2005.1513201","url":null,"abstract":"Medical imaging enjoys a reputation of applying multi-aspect sensing to construct internal maps of patients. The CAT scan evokes a concept of an X-ray probe moving around the patient; the multi-aspect data is processed to construct images of the areas of interest. In contrast, advanced acoustic imaging of objects on the ocean floor has to date relied only on high resolution sensing from limited aspect angles using data gathered on straight-line trajectories. With the increased application of UUVs, it is fitting to consider the factors that govern the design of sonar that can reconstruct images taking advantage of data with aspect diversity. One future paradigm will be circular synthetic aperture sonar (CSAS) using tomographic methods to reconstruct scenes of interest from data obtained over a full circular aperture. This presentation will address the parameters and procedures that play a role in CSAS and the relations between them that govern the performance of such a system. The design of a CSAS for high resolution surveillance of objects on the ocean bottom depends on parameters such as the diameter of the circular trajectory, the speed of the platform, the size of the imaged circle, and the ping repetition rate. The spatial and range resolutions are functions of the sonar signal wavelength and its bandwidth. These parameters define in turn the maximum allowable uncorrectable platform position errors, which lead to defining the requirements of the hypernavigation system that is needed to correct for the errors between the actual ping and receiver positions and the ideal sonar trajectory used in the main imaging computation. A possible realization of such a navigation system is described in the presentation. The ping repetition rate requirements are determined by the largest dimension and shape of the reflecting areas to be imaged. Analytical expressions relating all of the above mentioned design parameters are derived. These relationships define various performance metrics as functions of the deployment parameters, allowing optimization of search strategies to maximize area coverage rate for a choice of multiple circle patterns. Images of several objects using data from a turntable testbed at Lake Travis Test Station of the Applied Research Laboratories of the University of Texas at Austin will be shown and discussed in relation to the design and test parameters.","PeriodicalId":120840,"journal":{"name":"Europe Oceans 2005","volume":"62 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115098709","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Spatial resolution enhancement of microwave scanning radiometer data","authors":"M. Migliaccio, A. Gambardella, D. Theis","doi":"10.1109/OCEANSE.2005.1511793","DOIUrl":"https://doi.org/10.1109/OCEANSE.2005.1511793","url":null,"abstract":"In this paper we present a new numerical procedure to enhance the spatial resolution of microwave radiometers. The approach is physically based on the occurrence of multiple partially correlated measurements in the microwave scanning radiometers. Mathematically the approach is equivalent to a linear inversion problem and its solution is pursued by means of two numerical methods both based on the singular value decomposition (SVD). A set of numerical examples illustrates the first results of the study in which reference test-cases have been considered.","PeriodicalId":120840,"journal":{"name":"Europe Oceans 2005","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114333654","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Architecture of AUV systems for harbour protection and mine countermeasure","authors":"H. Kermorgant","doi":"10.1109/OCEANSE.2005.1513266","DOIUrl":"https://doi.org/10.1109/OCEANSE.2005.1513266","url":null,"abstract":"For MCM and Harbour Protection, a single AUV is rarely the most efficient way to complete a mission of reconnaissance. Most of time, a system of many vehicles is the appropriate means to realise the reconnaissance of the sea bottom. The paper focuses on the architecture of AUVs fleets for reconnaissance in the field of MCM and Harbour Protection, and proposes some answers to the following questions: What are the Concepts of Operations (CONOP) that can be used for reconnaissance? What are the parameters that define these CONOPs? How to define a 'good' architecture for a system of AUVs? What is the 'right' number of AUVs we need? What is the 'right' size of AUVs we need?.","PeriodicalId":120840,"journal":{"name":"Europe Oceans 2005","volume":"256 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114355439","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Measurement of deepwater ocean waves from a subsurface mooring","authors":"J. Wood, E. Terray, B. Strong, B. Singh","doi":"10.1109/OCEANSE.2005.1511703","DOIUrl":"https://doi.org/10.1109/OCEANSE.2005.1511703","url":null,"abstract":"We measured wave height and directional spectra in the open ocean from a subsurface mooring in 1400 meters water depth. Six months of data were recovered successfully at a site south of Australia where high-energy waves (with periods greater than 10 seconds) dominated the spectrum. Nondirectional wave height spectra were estimated from measurements of velocities made with an upward-looking ADCP mounted at the top of the mooring. Additional estimates of the nondirectional spectrum were obtained from a pressure sensor inside the ADCP, and from echo-location of the surface derived from the acoustic backscatter intensities measured by the ADCP. Mooring motion was removed using measurements from a second downward-looking ADCP mounted on the bottom of the float. Wave direction was determined from the velocities measured by the upward-looking ADCP using a variant of single point UVW processing, which permitted heading variations to be compensated continuously. We verified that the resulting horizontal and vertical velocities within the frequency bands containing appreciable wave energy are in quadrature, and that their coherence is close to unity. This paper describes the technique and assesses the quality of the resulting wave spectra and moments.","PeriodicalId":120840,"journal":{"name":"Europe Oceans 2005","volume":"37 10","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114085958","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The automatic fusion of classified sidescan sonar mosaics using CML-RTS and Markov random fields","authors":"S. Reed, I. Tena Ruiz, C. Capus, Y. Pétillot","doi":"10.1109/OCEANSE.2005.1513173","DOIUrl":"https://doi.org/10.1109/OCEANSE.2005.1513173","url":null,"abstract":"This paper presents a framework for registering and fusing classified sidescan sonar data. It builds on recent advances in navigation and registration for improved mosaicing, applying novel fusion algorithms to integrate data from overlapping sidescan survey lines to produce large scale classified mosaics. While typical mine-counter-measures (MCM) and rapid environmental assessment (REA) missions provide various over-lapping views of the same region of seafloor, research on sidescan image analysis has traditionally concentrated on the analysis of individual images. The available information from the other images, relating to the same region of seafloor, is generally not considered. The image registration and mosaicing process allows this complementary data to be fused, producing an improved final classification result. The sidescan imagery is first pre-processed through the application of advanced radiosity correction algorithms. Following radiosity correction, texture segmentation for the data presented in this paper is achieved using features derived from the averaged normalised power spectral density. The individual classification maps are georeferenced and coregistered using a Concurrent Mapping and Localisation Rauch-Tung-Striebel (CML-RTS) procedure. This uses local landmarks within the individual images and the AUVs navigation data to generate a more accurate and smooth navigation trajectory. This trajectory is used to produce the registered classification mosaics. The coregistered classification results are then fused to produce an improved class mosaic for the entire survey region. The fusion model uses a voting scheme to initialize the seafloor map after which a Markov random field (MRF) model is used to produce the final fused classification mosaic. The entire process (classification, registration and fusion) is demonstrated on real sidescan data taken at the Saclant Centre, La Spezia, Italy.","PeriodicalId":120840,"journal":{"name":"Europe Oceans 2005","volume":"58 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114882128","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Sound fields focused by a biconcave acoustic lens for normal and oblique incidence","authors":"T. Nakamura, M. Hashimoto, K. Mori, T. Kamakura, T. Anada","doi":"10.1109/OCEANSE.2005.1511685","DOIUrl":"https://doi.org/10.1109/OCEANSE.2005.1511685","url":null,"abstract":"In this report, a sound pressure field focused by a biconcave lens was investigated using the wave theory and the numerical methods of the parabolic equation (PE) method and finite difference time domain (FDTD) method for normal incidence. For oblique incidence, the hybrid method which combines ray theory and wave theory was used in the calculation. The experimental data were compared with the theoretical results shown above. The experimental on-axis characteristics around the focal point agreed well with the calculated results but disagreed with the results for in front and behind the focal region. It was found that the second peak existed behind the focal point for normal incidence, though there is no second peak in the theoretical results by the analytical method and the FDTD method. After the numerical analysis by the hybrid method and the PE method, the second peak was found at the same position as the experiment. This was thought to be caused by the influence of the edge of the lens, which has a finite size. The dependence of convergent characteristics for oblique incidence was also compared with the results by the hybrid method.","PeriodicalId":120840,"journal":{"name":"Europe Oceans 2005","volume":"111 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117183611","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Simulation of climate significant nonlinear tidal phenomena in the Euro Arctic seas","authors":"R. May","doi":"10.1109/OCEANSE.2005.1511748","DOIUrl":"https://doi.org/10.1109/OCEANSE.2005.1511748","url":null,"abstract":"A contribution of nonlinear tidal phenomena to formation and long-term variability of climatically significant fields of the Euro Arctic seas (Norwegian, Greenland, Barents, White and Pechora seas) is estimated in our research. Characteristics of residual tidal phenomena are received by numerical simulations: residual tidal level achieves significant values (up to 16 cm) in several regions of Euro Arctic seas (White Sea, areas around Svalbard, Spitsbergen bank, and along the sea side of the Russian Arctic). Maps of residual tidal currents were built: intensive residual currents are observed in the White Sea, Pechora Sea, regions near Svalbard, Spitsbergen bank, and Bear and Hope islands. A possibility for adjunction of long-period tides by energy of main diurnal and semidiurnal tides is reported; amplitudes of nonlinear long-period tidal waves were evaluated. The impact of nonlinear components of motion and continuity equations on formation of different oceanographic phenomena was determined by means of numerical experiments: it was found that convective nonlinearity noticeably contributes into formation of climatically significant nonlinear tidal phenomena (residual tidal level and currents, and low-frequency tidal waves). An example of the White Sea, it was determined that the tidal phenomena play important role in formation of thermohaline structure of tidal sea waters.","PeriodicalId":120840,"journal":{"name":"Europe Oceans 2005","volume":"109 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124676423","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}