2013 IEEE International Underwater Technology Symposium (UT)最新文献

{"title":"Towards real-time control of a double gimbaled acoustic probe for measurement of manganese crusts thickness","authors":"T. Sato, B. Thornton, A. Bodenmann, A. Asada, T. Ura","doi":"10.1109/UT.2013.6519880","DOIUrl":"https://doi.org/10.1109/UT.2013.6519880","url":null,"abstract":"Manganese crusts are the focus of much attention as a potential mineral resource. The crusts form a thin layer of deposit that is distributed over wide areas on the surface of seamounts. To date, the only way to know the thickness of manganese crusts has been through sampling and drilling, but these methods are expensive and time consuming. We have developed an acoustic device that can determine the thickness of manganese crusts during surveys using an underwater robot. This system has worked successfully during sea trials on the flat top of Takuyo-Daigo seamount, located in the northwest Pacific. However, manganese crusts are known to be distributed not only on flat surfaces but also on the slopes of seamounts, and while accurate measurements are possible on relatively flat areas of the seafloor, the quality of measurements made on steep slopes are degraded by the large angle of incidence of the necessarily narrow beam of the acoustic probe. The aim of this research is to investigate potential methods to improve data return rates of manganese crust thickness measurements on steep slopes. The effects of the angle of incidence on the acoustic reflections measured from a manganese crust sample are determined experimentally and it is found that an angle of incidence larger than 3° has a detrimental effect on the measured reflected signal. High resolution 3D bathymetry data acquired using the 3D visual mapping device `SeaXerocks' was analyzed, so as to determine the actual local inclination of crust covered seafloor. Based on the analysis, it is suggested that a double gimbal system should be introduced to actively control the angle of the acoustic probe so that the acoustic beam enters the seafloor orthogonally. In order to achieve real-time control, a method to determine the relative angle based on sparse measurements of the seafloor is necessary. The control algorithm developed uses two range sensors, consisting of a line projected laser and a single point acoustic range sensor, mounted on front and back of underwater robot so that the relative inclination of seafloor can be determined in real-time. The performance of the developed double gimbal system has been assessed in water tank experiments working on simple sloped models of known geometry. The experiments demonstrate an improvement in the intensity of the acoustic reflections from the slopes as a result of the active control. The setup was used during sea trials at a manganese encrusted seamount to survey steeply sloped surfaces, and the results of the sea trials are presented.","PeriodicalId":354995,"journal":{"name":"2013 IEEE International Underwater Technology Symposium (UT)","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117222253","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":"Development of an underwater gravimeter and the first observation by using autonomous underwater vehicle","authors":"M. Shinohara, T. Yamada, T. Kanazawa, K. Uehira, H. Fujimoto, T. Ishihara, A. Araya, K. Iizasa, S. Tsukioka","doi":"10.1109/UT.2013.6519864","DOIUrl":"https://doi.org/10.1109/UT.2013.6519864","url":null,"abstract":"We developed an underwater gravimeter for exploration of a seafloor hydrothermal deposit. Our hybrid gravimeter system consists of an underwater gravimeter and an underwater gravity gradiometer. We adopted Micro-g LaCoste S-174 as a gravity sensor. The sensor is mounted on a gimbal mechanism with a fiber gyroscope. A titanium sphere contains the sensor system. Maximum depth rating is 4,200 m. The data are sent to a recording system housed in another cylinder-shape capsule. The whole system is controlled and monitored via acoustic link of the AUV. In September 2012, the first practical measurement in marine area was carried out by using JAMSTEC's AUV URASHIMA to evaluate performance of the system. The gravimeter and gravity gradiometer were simultaneously mounted on the URASHIMA and the first measurement was performed in Sagami-Bay. From the survey, we obtained the gravity data and supplemental data for compensation of the gravity data with good quality. According to preliminary analyses, the resolution of the gravity data from the first practical measurement is estimated to reach 0.1 mgal.","PeriodicalId":354995,"journal":{"name":"2013 IEEE International Underwater Technology Symposium (UT)","volume":"91 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131922324","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":"Modeling of shallow water ambient noise based on adiabatic mode theory","authors":"A. Chang, Yu-Chen Cheng, Chi-Fang Chen, Hsiang‐Chih Chan, Sheng-Fong Lin","doi":"10.1109/UT.2013.6519879","DOIUrl":"https://doi.org/10.1109/UT.2013.6519879","url":null,"abstract":"State-of-the-Art noise prediction has been used to model noise emissions from industrial facilities, shipping activity in underwater environment to estimate noise level contours beyond the source area, and to determine specific impacts at potentially sensitive receptors, including marine mammals, etc. This paper presents the ambient noise modeling using adiabatic mode theory as acoustic propagation model to evaluate the noise statistics including temporal coherence and spatial variability offshore western Taiwan. In this model, the ocean model (Taiwan Coastal Ocean Nowcast/Forecast System, TCONFS, formulated on the basis of the Princeton Ocean Model) generating time varying/spatial dependent temperature profiles for water column variability, and geo-acoustic database are used as environmental inputs to this model. The modeling results demonstrate the temporal/spatial variability induced by time varying ocean model output, manifested by measured data. (This work is supported by National Science Council of Taiwan).","PeriodicalId":354995,"journal":{"name":"2013 IEEE International Underwater Technology Symposium (UT)","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134082458","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":"Estimation and analysis of the underwater noise during construction of offshore wind farm in the west coast of Taiwan","authors":"Henry H. J. Tsai, Sheng-Fong Lin, Chi-Fang Chen, Tien-Siang Ling, Cheng-Cyuan Fan, Wei-Chun Hu","doi":"10.1109/UT.2013.6519869","DOIUrl":"https://doi.org/10.1109/UT.2013.6519869","url":null,"abstract":"Wind-generated electricity has been one of the greenest energies in the world Based on Global Offshore Wind Farms Database, there are enormous potentials for wind energy utilization in the Taiwanese Straits, especially the west coast. However, there are many habitats of marine mammals in this area, so we cannot neglect the environmental problem due to the issue of construction noises produced by the offshore wind farms. The impact range of the construction noise arising from the offshore wind turbine pilling can be precisely simulated, based on the hydrographic, bathymetric and sedimentation data. The result would be taken as a reference for the construction of the offshore wind farms off Taiwan's west coast. This work is supported by Bureau of Energy and Industrial Technology Research Institute under NTU project NSC 100-2221-E-002-027.","PeriodicalId":354995,"journal":{"name":"2013 IEEE International Underwater Technology Symposium (UT)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129697800","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":"Laser-induced breakdown spectroscopy for in situ chemical analysis at sea","authors":"B. Thornton, T. Sakka, T. Takahashi, A. Tamura, A. Matsumoto, T. Ura","doi":"10.1109/UT.2013.6519823","DOIUrl":"https://doi.org/10.1109/UT.2013.6519823","url":null,"abstract":"Spectroscopy is emerging as a technique that can expand the envelop of modern oceanographic sensors. The selectivity of spectroscopic techniques enables a single instrument to measure multiple components of the marine environment, and can form the bases of versatile tools to perform in situ geo-chemical analysis. This work investigates emission spectroscopy using laser-induced plasmas to perform multi-element chemical analysis of liquids and solids at sea. In situ measurements of both liquids and solids have been successfully performed at sea using the 3000m depth rated prototype I-SEA (In situ Seafloor Element Analyser). Techniques aimed at optimising the signals observed from plasmas generated at high pressure are described and their mechanisms discussed. I-SEA is just an example of a new generation of chemical cameras (ChemiCam) that can probe different aspects of the environment. It is hoped that through integration with platforms such as underwater vehicles, drilling systems and subsea observatories, this technology will contribute to more efficient scientific surveys, and serve as a tool to facilitate both spatially and temporally continuous study of the ocean.","PeriodicalId":354995,"journal":{"name":"2013 IEEE International Underwater Technology Symposium (UT)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131295885","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":"Optimal positioning of autonomous marine vehicles for underwater acoustic source localization using TOA measurements","authors":"B. Ferreira, A. Matos, N. Cruz","doi":"10.1109/UT.2013.6519898","DOIUrl":"https://doi.org/10.1109/UT.2013.6519898","url":null,"abstract":"In opposition to the surface, no common solution is available for localization of active objects underwater. Typical solutions use acoustics as a means to implicitly measure ranges or angles and consequently determine the position of a transmitter. If the receivers are synchronized among themselves, the position of the transmitter can be estimated based on the time-of-arrivals (TOA). The confidence on the estimate varies with respect to the relative positions of the receivers and the transmitter. In this paper, we present recent developments for optimal 3D positioning of TOA sensors based on the a metric that uses the Fisher information matrix. We give the necessary conditions to obtain the best possible estimate. To our best knowledge, no analytical solution has been yet presented for this problem. We complete and validate our study with a simulation of optimal positioning of four TOA sensors.","PeriodicalId":354995,"journal":{"name":"2013 IEEE International Underwater Technology Symposium (UT)","volume":"107 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123231873","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":"Continuous mapping of radionuclides on the seafloor using a towed gamma ray spectrometer","authors":"B. Thornton, S. Ohnishi, Y. Yano, S. Sasaki, T. Ura, N. Odano, T. Fujita","doi":"10.1109/UT.2013.6519825","DOIUrl":"https://doi.org/10.1109/UT.2013.6519825","url":null,"abstract":"An instrument to continuously map the distribution of radionuclides on the seafloor has been developed and applied to survey radioactive discharge from the Fukushima Dai-ichi Nuclear Power Plant following the M9.0 earthquake and tsunami that struck the east coast of Japan on March 11 2011. The towed gamma ray spectrometer has been deployed off Fukushima and has to date, been used to monitor radionuclide distribution over a total distance of more than 120 km. Here, we introduce the results of measurements made along three transects within an 80km radius of the plant, focusing on a 22km long transect off Iwaki. While the levels of the natural gamma ray emitter 40K remained constant, the levels of 137Cs and 134Cs were found to vary significantly with location. The in situ measurements show good agreement with laboratory analyzed samples obtained during the survey, indicating that the technique described provides an effective solution for rapid, low cost monitoring of radioactive material on the seafloor.","PeriodicalId":354995,"journal":{"name":"2013 IEEE International Underwater Technology Symposium (UT)","volume":"87 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121366976","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":"Optical methods to monitor temporal changes at the seafloor: The Lucky Strike deep-sea hydrothermal vent field (Mid-Atlantic Ridge)","authors":"J. Escartín, R. García, T. Barreyre, M. Cannat, N. Gracias, A. S. M. Shihavuddin, E. Mittelstaedt","doi":"10.1109/UT.2013.6519838","DOIUrl":"https://doi.org/10.1109/UT.2013.6519838","url":null,"abstract":"Newly developed image processing techniques, including gigamosaicing, video-based 3D terrain reconstruction, and video-based fluid velocimetry have provided key information to understand the distribution, nature, and quantification of hydrothermal activity at a deep sea vent field (Lucky Strike, Mid-Atlantic Ridge). These imaging techniques have been coupled with seafloor instrumentation and sampling, allowing us to develop a comprehensive approach to study active processes in the submarine environment that can be transferred to other study areas.","PeriodicalId":354995,"journal":{"name":"2013 IEEE International Underwater Technology Symposium (UT)","volume":"97 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129611607","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":"Soft acoustic modem development for shallow water environment","authors":"T. Santoso, E. Widjiati, Wirawan, G. Hendrantoro","doi":"10.1109/UT.2013.6519834","DOIUrl":"https://doi.org/10.1109/UT.2013.6519834","url":null,"abstract":"Development of an underwater acoustic communication system is a necessity for the majority of the nation as a sea area of Indonesia. Most area s of the ocean in Indonesia is shallow, the environment has unique characteristics compared to other countries. It is a challenge in the research underwater acoustic communication system. This paper presented a preliminary study of the developing of soft acoustic modem testbed for underwater acoustic communication system with OFDM technique. Modem has been implemented on a PC with Matlab, with the objective to evaluate the algorithm development. Image file in JPEG format is encoded with a discrete cosine transform (DCT). To improve performance, information is encoded with a forward error correction, FEC-Hamming. The system uses BPSK modulation, OFDM transmission techniques, and using acoustic signal as carrier wave. In this system, the occupation bandwidth is 5.3 kHz, transmission rate of 3.7 k sps, and center frequency at 13.3 kHz. As an initial stage, the model presented in the form of simulator tesbed passband, and is treated with the propagation parameters that was obtained from measurements in a Towing Tank in previous experiment. The next stage is tesbed evaluation through experimental in a laboratory, such the effect of conversion process from electrical to audio signal at PC sound card and the capability of the receiver to recover the information.","PeriodicalId":354995,"journal":{"name":"2013 IEEE International Underwater Technology Symposium (UT)","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128845446","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":"Submarine topography and sediment distribution after the 11 March 2001 tsunami impact in Kesen-numa Bay, Miyagi, Japan","authors":"K. Akimoto, K. Yakita, T. Hokamura, T. Yoshinaga, M. Yoshioka, I. Sakamoto, Y. Takino","doi":"10.1109/UT.2013.6519836","DOIUrl":"https://doi.org/10.1109/UT.2013.6519836","url":null,"abstract":"In Kesennuma Bay, the study area, the sea bottom was scoured, the geography and sediments were altered, and much debris, oil, and chemical materials flowed into the sea from land as a result of the 2011 0311 tsunami. Highly precise information for the change of geography and sediment distribution by this tsunami applicable to the reduction of tsunami damage can be obtained by this investigation. We collected data on water depth, refraction intensity by acoustic systems, and photographs by AUV and video films by ROV. We evaluated the marine environmental change based on a comparison with a chart published before this earthquake. The data suggest that the geographical changes by impact of the tsunami restricted to the inner bay and Ohshima strait, and much debris and clastic particles were transported and the dune was formed by the tsunami's backwash.","PeriodicalId":354995,"journal":{"name":"2013 IEEE International Underwater Technology Symposium (UT)","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115139980","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}