2013 IEEE/OES Acoustics in Underwater Geosciences Symposium最新文献

{"title":"Jumbo squid (Dosidicus gigas) in situ target strength measurements in northwest Mexico","authors":"Héctor Villalobos, Fernando Manini-Ramos, C. Salinas-Zavala, P. Brehmer","doi":"10.1109/RIOACOUSTICS.2013.6683994","DOIUrl":"https://doi.org/10.1109/RIOACOUSTICS.2013.6683994","url":null,"abstract":"In order to convert acoustic abundance indexes into biomass is essential to establish the relationship between squid size dorsal mantle length (DML) and acoustic Target Strength (TS). We had carried out in situ measurement in 2012 off Baja California on Dosidicus gigas. For both frequencies, we found significant differences between modes of measured and predicted TS distributions, 6 and 11 dB for 120 and 38 kHz, respectively. It is known that TS varies with several factors, including echosounder characteristics and transducer frequency and mainly the target orientation in the acoustic beam and many other biological variables. In relation to squid behavior, during the capture operation small fish schools were observed in the area, which may suggest that squid were feeding. Further observations and analysis are necessary in order to obtain reliable TS - DML relationship for jumbo squid before attempting acoustic biomass assessment methods to this important species.","PeriodicalId":245877,"journal":{"name":"2013 IEEE/OES Acoustics in Underwater Geosciences Symposium","volume":"58 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127481560","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":"Hydroacoustics estimates of sardine (Sardinella brasiliensis) in the Brazilian coast, sampling strategies and the effects on fish distribution and biomass","authors":"L. Madureira, S. Weigert, M. Pinho, P. Lumi, A. Duvoisin","doi":"10.1109/RIOACOUSTICS.2013.6684015","DOIUrl":"https://doi.org/10.1109/RIOACOUSTICS.2013.6684015","url":null,"abstract":"Biomass assessment of small pelagic fish stocks with acoustics depends on the use of scientific echo sounders that transmit/receive acoustical energy, quantify the echoes and generate the parameter Nautical Area Scattering Coefficient (NASC), proportional to the density of the live targets detected in the water column and within the acoustic beam. In order to convert the acoustic density parameter NASC into biological density, it is necessary to identify the organisms detected acoustically, at the level of species, as well as the proportions, in number, between species. NASC is then decomposed into biological density as a function of the species dependent Target Strength (TS) parameter and the proportion among species, within body size classes, that generated the backscattered energy. Therefore sampling along ship track is intrinsic to the method and the mid water trawl is considered the equipment that best meets the needs of biological sampling during acoustics biomass cruises. Between January 2008 and March 2010, four surveys were conducted to estimate the stock biomass of the Brazilian sardine (Sardinella brasiliensis) aboard Oc. V. Atlantico Sul. S. brasiliensis is a small pelagic fish with fusiform body, great swimming ability and consistent avoidance reactions. In all cruises we operated a calibrated SIMRAD EK 500 scientific echo sounder. In cruise I (2008) sampling strategy was based on a mid water trawl hauled from the research vessel. A total of 22 fishing hauls were performed and in only five, sardines were caught, representing just 2.25%, in number, of the total catches. Data processing generated an estimated biomass of 358 t of sardines, incompatible with the 74,630 t caught by the fishing fleet in 2008. Observations during the hauls indicated the escapement of sardine, swimming in front of, or avoiding the net to upper or deeper depths, and not being caught. Such observations demonstrated that the used mid water trawl was not efficient for sardine in that area with that vessel, which defined the need of a more efficient sampler. In Cruise II and III tests were performed with a purse seiner equipped with multi beam sonar. This boat sampled fish schools reported from the research vessel detections with the scientific echo sounder. Purse seiner participation was restricted and only 2 and 3 samples were taken in Cruise II and III respectively, in 2009. Sardine biomass estimates were 12,709 t and 27,928 t respectively, still below the reported year catch of 83,286 t. In 2010 we finally had a purse seiner working full time in parallel with the research vessel, along cruise IV. With this additional sampling system biomass estimation were of 62,569 t, a value very close to the 62,134 t landings of the sardine fleet in the same year. Mid water trawl consistently caught small sardine while the purse seine caught more and larger individuals due to the ability of the larger individuals to avoid the trawling devices and the selectivity of the pur","PeriodicalId":245877,"journal":{"name":"2013 IEEE/OES Acoustics in Underwater Geosciences Symposium","volume":"109 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124693509","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":"Gaussianity analysis of ambient noise in littoral tropical water","authors":"R. Shastri, Y. Joshi, Arnab Das","doi":"10.1109/RIOACOUSTICS.2013.6683977","DOIUrl":"https://doi.org/10.1109/RIOACOUSTICS.2013.6683977","url":null,"abstract":"The performance predictions for sonar assume a background of Gaussian noise, however, deviation from this assumption may generate false alarms. This paper attempts to find out whether the ambient noise in tropical waters of the western coast of Indian continental is Gaussian. Gaussianity is tested using graphical, numerical and verified using formal normality tests like Kolmogorov Smirnov (KS) test and Lilliefors (LF) test. Ambient noise recorded at 30 m of depth using passive sonar is found non-Gaussian. The percentage of Gaussianity is calculated periodically eight times over the day at an interval of one hour every five minutes recording. The effect of known noise sources like wind speed, tide height and temperature, on the percentage of Gaussianity, is found linear.","PeriodicalId":245877,"journal":{"name":"2013 IEEE/OES Acoustics in Underwater Geosciences Symposium","volume":"375 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134063931","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":"Data processing of hydroacoustic data as support to mapping and characterization of seafloor","authors":"Giankarlo R. F. Fernandes de Oliveir, M. L. S. Nogueira, H. Vital, Josibel Gomes de Oliveira Junior","doi":"10.1109/RIOACOUSTICS.2013.6684021","DOIUrl":"https://doi.org/10.1109/RIOACOUSTICS.2013.6684021","url":null,"abstract":"This work aims to present a processing flow designed for shallow seismic data acquired in the northern continental shelf of Rio Grande do Norte State, adjacent to Areia Branca city. This area was choose because of the presence of an important incised-valley system, between depths of 15 m to 25m. The understanding of the formation and cenozoic filling of incised valleys has contributed more and more to studies with similar reservoirs of oil and gas. The data were acquired with a sub-bottom profiler type chirp, using small boats. The signal penetration reached approximately 45m with subsurface water depths of up to 40m. During activities were acquired information of parameterization software acquisition, software and processing tools. All data were integrated with GIS (Geographic Information Systems). Processing consisted in the adaptation of coordinate system, spectral analysis, optimization of the process of removing the water depth, application of low-pass filters and FK, according to the need of each section and bathymetric correction. The results revealed a smoothing effect of the waves, noise attenuation and multiple best contrasting the different types of reflectors thus enabling the identification of different seism facies in existing sections.","PeriodicalId":245877,"journal":{"name":"2013 IEEE/OES Acoustics in Underwater Geosciences Symposium","volume":"38 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133868076","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":"Routine acoustic data as new tools for a 3D vision of the abiotic and biotic components of marine ecosystem and their interactions","authors":"A. Bertrand, D. Grados, Jérémie Habasque, Ronan Fablet, Michael Ballón, Ramiro Castillo, A. Chaigneau, M. Gutiérrez, E. Josse, Gildas Roudaut, A. Lebourges-Dhaussy, P. Brehmer","doi":"10.1109/RIOACOUSTICS.2013.6683995","DOIUrl":"https://doi.org/10.1109/RIOACOUSTICS.2013.6683995","url":null,"abstract":"Here we show how routine acoustic data, primarily collected for stock assessment, allows for a 3D vision of the abiotic and biotic components of marine ecosystem and to study their interactions. Data, which can be obtained from any vessel geared with multi-frequency echosounders, provide relevant information to study the impact of physical processes on biogeochemical and ecological processes marine life and extracting valid information about the pelagic habitat and its spatial structure. All these data are to develop actual Ecosystem-based Fisheries Management in the current context of climate change. As an example we propose a synthesis of a scientific program developed in the Humboldt Current system off Peru which is the most productive in terms of fish and encompasses a shallow and intense oxygen minimum zone.","PeriodicalId":245877,"journal":{"name":"2013 IEEE/OES Acoustics in Underwater Geosciences Symposium","volume":"35 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115603754","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":"Proper environmental reduction for attenuation in multi-sector sonars","authors":"Rodrigo de Campos Carvalho, Aluizio Maciel de Oliveira Junior, J. Clarke","doi":"10.1109/RIOACOUSTICS.2013.6684008","DOIUrl":"https://doi.org/10.1109/RIOACOUSTICS.2013.6684008","url":null,"abstract":"Multibeam backscatter data represent a major seabed discrimination tool. For seafloor characterization, however, one of the most significant limitations is the absolute calibration. There are many components of this and environmental and frequency controls on the backscatter level are two of the most important ones. As many multibeam backscatter data are reduced imperfectly for attenuation, this paper examines how important it is and how consequential it is. It introduces a precise and explicit method to properly compensate given a CTD and full knowledge of specific sector frequencies used, as long as the absorption coefficient already applied is preserved. Example cases are given for two different frequencies for historical data that were imperfectly compensated and the method is demonstrated.","PeriodicalId":245877,"journal":{"name":"2013 IEEE/OES Acoustics in Underwater Geosciences Symposium","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115257528","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":"Adaptive Multi-Feature Fusion for underwater diver classification","authors":"Yang Juan, Xu Feng, Wei Zhiheng, An Xu-dong, Liu Jia, Jing Yongqiang, Wen Tao","doi":"10.1109/RIOACOUSTICS.2013.6684022","DOIUrl":"https://doi.org/10.1109/RIOACOUSTICS.2013.6684022","url":null,"abstract":"This paper discusses a technique for the classification of divers, underwater vehicles and other similar targets based on adaptive multi-feature fusion. This technique mainly uses target features, e.g., image feature, moment feature and HRRP (high resolution range profile) features selected by an Adaptive Feature Fusion method. The sea trial data collected in Sanya in January, 2009 are processed by the algorithm. Real data processing results demonstrate the Adaptive Multi-Feature Fusion based technique can effectively reduce the error probability.","PeriodicalId":245877,"journal":{"name":"2013 IEEE/OES Acoustics in Underwater Geosciences Symposium","volume":"86 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131457958","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":"Preliminary results on the high-resolution seismic survey at Puerto Foster Bay, Deception Island, Antarctica","authors":"Arthur Ayres Neto, Fabio Jose Guedes Magrani, Ana Lucia Dauern, Rodolfo Jasão Dias, A. Salaroli, F. Louza","doi":"10.1109/RIOACOUSTICS.2013.6683997","DOIUrl":"https://doi.org/10.1109/RIOACOUSTICS.2013.6683997","url":null,"abstract":"A high-resolution seismic survey was conducted within Puerto Forster Bay, Deception Island, Antarctica, in order to study the seafloor geological characteristics. This bay was originally the volcano's crater and became a bay after part of the wall was destroyed allowing the sea water to come in. There are areas of long term geothermal activity and it is classified as a restless caldera with a significant volcanic risk. The results showed the presence of four different seismic echo-characters. The first one is defined by a series of sub-bottom reflectors parallel to the seafloor indicating the deposition under low energy environment. The other two are characterized by a chaotic / transparent sub-bottom layer, maybe associated to deposits of volcanic material or slided debris from the flanks of the volcano. Moreover, these echo-characters are associated to more irregular seafloor morphology. No evidences of gassy sediments, faults or fluid migration in the seafloor were observed on the seismic records indicating that recent volcanic activity observed in the period between 1967 and 1970 is happening in another point of the volcano separated from the old crater.","PeriodicalId":245877,"journal":{"name":"2013 IEEE/OES Acoustics in Underwater Geosciences Symposium","volume":"51 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133980520","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":"Ultra-shallow water geophysics surveys for a Pseudo-3D palaeochannel reconstruction, Lagoon of Venice, Italy","authors":"Jorge A. G. de Souza, S. Donnici, F. Madricardo, I. Corrêa","doi":"10.1109/RIOACOUSTICS.2013.6684012","DOIUrl":"https://doi.org/10.1109/RIOACOUSTICS.2013.6684012","url":null,"abstract":"The Lagoon of Venice (LV) is a shallow lagoon located in the Mediterranean region, NE Italy. It is connected to the Adriatic Sea by three inlets. The LV is the largest Italian lagoon with an area of 550 km2, and is characterized by the presence of a complex occurrence of salt marshes, tide flats and navigation channels. The LV began to form about 6000 yrs. BP related to the marine transgression occurred in the end of the Wurm glaciation. Since then, a combination of natural processes and intense human activities determined its morphological evolution. Recent studies demonstrated that the use of sub-bottom profilers can be very useful to obtain a description of ancient phases of the lagoon evolution. In this contribution, we present the results concerning ultra-shallow water (<;1 m depth) acoustic survey in the central lagoon area between the industrialized area of Marghera and the city of Venice. The aim of our work is to reconstruct the sub bottom architecture of a very anthropised environment through a multidisciplinary approach using acoustic and environmental data. The surveys were carried out using a modified ELAC echosounder with a 30 kHz transducer. The positions were defined using a DGPS system. The survey lines were done through parallel lines spaced 50 m in south-north direction. In correspondence with interesting acoustical discontinuities 14 ground cores were extracted with the help of a rotation method with water circulation and the position of the cores was done using a DGPS. The geophysics data were acquired using the software Ecosonda v.3.04.vi (CNR-Rome) and processed with the software MostraDati (CNR-Roma). Acoustic data allowed the reconstruction of three paleochannels and their meandering paths and also a pseudo-3D reconstruction by the interpolations of the mapped reflectors depth. In particular, the central one denominated as PC02 was intersected by the core SG25. The stratigraphic record presents mainly clayey-silty sediments between -1.2 to -5.2 m and sandy sediments from -5.2 m to -6.60 m from the m.s.l. The C14 dating on a mollusk shell taken at -5.2 m between the two facies allows the reconstruction of the paleochannel shape 1600 ± 90 cal yrs. BP. In the southern side of the acoustic profile, were identified inclined reflectors who correspond to the palaeochannel point bar migration for about 20-30 m towards north. Was also observed a variation in the depositional form of this point bar migration separated in two different phases: before a higher energetic regime with sand deposition and channel migration, later a finer filling and apparently no migration. This variation could be related to a change of the hydrodynamics of the area due to a climate change between the IV and VI century AD.","PeriodicalId":245877,"journal":{"name":"2013 IEEE/OES Acoustics in Underwater Geosciences Symposium","volume":"115 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123040259","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":"Passive pressure and vector geoacoustic inversion offshore Amazon Rio mouth: A sensitivity study","authors":"Qunyan Ren, J. Hermand","doi":"10.1109/RIOACOUSTICS.2013.6683979","DOIUrl":"https://doi.org/10.1109/RIOACOUSTICS.2013.6683979","url":null,"abstract":"Ship noise is a good resource for passive waveguide characterization in coastal areas due to the high maritime traffic density. Its broadband spectrogram often exhibits environmental determined interference pattern but has weak dependence on source spectral characteristics. The interference pattern has been exploited in an acoustic interferometry technique to characterize the main sediment geoacoustic parameters. To estimate more environmental parameters and examine the benefits of using different acoustic fields, numerical tests using pressure, vertical pressure gradient and vertical waveguide impedance are performed under the environmental model of offshore Amazon Rio mouth (CANOGA 12). The inversion is performed by a global optimization through minimizing a Bartlett-type cost function over a number of discrete frequencies. The synthetic test results demonstrate that the vertical waveguide impedance can give more reliable and higher resolution results compared to that of pressure and vertical pressure gradient, especially for the density of bottom layers. The numerical results comply well the preliminary results obtained from the CANOGA 12 ship noise data, in which, the vertical waveguide impedance also provides closer estimates to the ground truth than that of pressure and pressure gradient. Both synthetic and real data promising results of the vertical waveguide impedance are originated in its intrinsic feature of source spectral level independent, which is preferred in passive acoustics.","PeriodicalId":245877,"journal":{"name":"2013 IEEE/OES Acoustics in Underwater Geosciences Symposium","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124040259","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}