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

{"title":"Protection of a receiving area from underwater pile driving noise using large encapsulated air bubbles","authors":"M. Wochner, P. Wilson, Kevin M. Lee","doi":"10.1109/RIOACOUSTICS.2013.6683986","DOIUrl":"https://doi.org/10.1109/RIOACOUSTICS.2013.6683986","url":null,"abstract":"A proof-of-concept noise abatement system using encapsulated bubbles was applied to pile driving noise with successful results. The system was unique in that it was built to protect a receiving area from the noise generated by pile driving noise. Results from this experiment will be discussed, and in addition laboratory tests demonstrating the potential of using such a system will also be covered.","PeriodicalId":245877,"journal":{"name":"2013 IEEE/OES Acoustics in Underwater Geosciences Symposium","volume":"121 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":"116837112","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 canyons in Brazilian Equatorial Margin: The Apodi-Mossoró canyons, NE-Brazil","authors":"N. M. Almeida, H. Vital","doi":"10.1109/RIOACOUSTICS.2013.6683989","DOIUrl":"https://doi.org/10.1109/RIOACOUSTICS.2013.6683989","url":null,"abstract":"The lack of data of continental slope regions and the perspective to oil explorations in these areas stimulated this study. Multibeam data was collected in continental slope of the Potiguar basin with the aim of modeling the seafloor. Different submarine canyons were mapped. In this work the focus are a set of 4 canyons we believe were originated due to the influence of Apodi-Mossoró River when the sea level was lower than presently. The canyons were named a1 to a4 canyons. Landslide structures and gullies were mapped in the walls of these canyons indicating erosional deposicional style.","PeriodicalId":245877,"journal":{"name":"2013 IEEE/OES Acoustics in Underwater Geosciences Symposium","volume":"53 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":"115569504","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":"Small scale acoustical, biological and environmental integrated study","authors":"L. Madureira, M. Pinho, C. Aseff, S. Weigert, P. L. Costa, A. Duvoisin","doi":"10.1109/RIOACOUSTICS.2013.6684006","DOIUrl":"https://doi.org/10.1109/RIOACOUSTICS.2013.6684006","url":null,"abstract":"Two acoustic assessment cruises were carried out (February, 2010 and January,2011) in three, 10 by 10 nautical mile exploratory oil blocks, previously to the start of the drilling operation, within a sardine (Sardinella brasiliensis) fishing area. Biological data were collected with zooplankton and mid water trawl hauls. Hydroacoustics with echo-integration were conducted day and night along the whole block areas to detect zooplankton and fish spatial and vertical distribution. Hydroacoustic data were obtained with an echo sounder SIMRAD EK 500 connected to two, 38 and 120 kHz, split-beam transducers. The surveys were performed along 11 parallel transects in each block, where 9 CTD (Conductivity, Temperature, Depth profiler) stations were done. The echo-integration method estimates the acoustic density of the organisms along the water column and within a given area, such density is proportional to the biological density. The method is based on the amount of backscattered energy, integrated within the acoustic beam sampling volume and for a given sampling distance. These values are converted to the parameter NASC (Nautical Area Scattering Coefficient). Average NASC values were similar and relatively low for the two cruises, with no fish schools being detected. However, we observed differences in the NASC values, with the highest densities of organisms associated with specific sectors. The CTD data revealed the presence of the shallower and warmer TW (Tropical Water) and the deeper and colder SACW (South Atlantic Central Water). Surprisingly we detected internal and significant differences in the spatial temperature distribution within each block, in the 2010 cruise. Satellite images showed that the north block (in Campos Basin) was under the effect of a front and the south blocks (in Santos Basin) under the effect of a cyclonic vortex. Local topography and the abrupt change in the coast line orientation favor the generation of meanders and vortices by the Brazil Current (BC) in the area. These structures induce upwellings along the shelf break, pushing SACW to shallower depths, approaching the lower temperature isotherms to surface. Also, cold water is pushed towards the coast and shelf water, offshore. In 2010 the highest NASC values were found in the west part of Campos Basin block, occupied by the relatively cooler waters. Two other cruises were carried on (May and September, 2012) and preliminary analyses indicate temperature gradient of up to 4°C in the Campos Basin block, in the 40 m stratum, in May cruise. Considering block dimensions and the features detected in at least two out of four cruises we can speculate that the oceanographic fronts we detected within the blocks are part of vortexes which operate in larger scales and that those features must be more common in the region than previously assumed. Also, as higher acoustic densities showed association with cold water we suggest that these vortices and meanders may affect sardine eggs a","PeriodicalId":245877,"journal":{"name":"2013 IEEE/OES Acoustics in Underwater Geosciences Symposium","volume":"27 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":"125465564","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":"Aggregative and schooling behaviour of small pelagic fish schools through echo type characteristics","authors":"P. Brehmer, Abdoulaye Sarré, L. González, P. Cotel, J. Hermand, G. Francois","doi":"10.1109/RIOACOUSTICS.2013.6683992","DOIUrl":"https://doi.org/10.1109/RIOACOUSTICS.2013.6683992","url":null,"abstract":"In this work we compare the result obtained by in situ echosounder measurements on eastern Venezuelan and south Sénégal coastal shelves where Sardinella aurita was the predominant species occurred in fish school structure. The both stocks are known as genetically independent. Persistent school typology was already described by Petitgas and Levenez (1996) analysing Senegalese echogram database. We compiled and analyzed an acoustic database (7 surveys) of Venezuelan fish school populations. The echo type typology encountered in the both countries is similar over the year. On the others hand, two standardized acoustics surveys have been carried out in 1999, with the same research vessel and echosounder (38 kHz) in Sénégal and Venezuela. The `echointegration by shoal¿ method was performed on the data collected on both stocks. The observed fish school descriptors (energetic, morphologic and spatial) showed that the differentiation between day and night fish schools was mainly due to morphologic variables (fractal dimension). In Venezuela the echo types were different between day and night as in Sénégal, but on the entire diel cycle the quantitative and qualitative characteristics of fish schools were similar on both ecosystems. Both acoustic fish school populations are similar; they are constituted by a same dominant species Sardinella aurita. Observation of small pelagic fish school during the night is not unusual. The schooling behaviour and the diel aggregative dynamics of small pelagic fish around the world are discussed according our result and literature review. School morphology appears to be common to large number of species, and aggregative dynamics, species dependent.","PeriodicalId":245877,"journal":{"name":"2013 IEEE/OES Acoustics in Underwater Geosciences Symposium","volume":"24 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":"127793414","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":"Hydroacoustic surveys as contribution to the study of spawning aggregations of Nassau Grouper (Epinephelus striatus) in the Yucatan","authors":"E. Linares, J. Guillard, P. Schneider, P. Caballero, F. Gerlotto, P. Brehmer","doi":"10.1109/RIOACOUSTICS.2013.6683993","DOIUrl":"https://doi.org/10.1109/RIOACOUSTICS.2013.6683993","url":null,"abstract":"One of the main species in the Caribbean cost of Yucatan-Mexico is the Mero (Epinephelus striatus), but the fisheries are beginning to go down and the principal reason could be the over-catch. The objective of this work is to study the aggregations of the Nassau Grouper, as well as the rest of the fish populations associated with the slope of the Mexican Caribbean of the Yucatán Peninsula, using hydroacoustic methods, and to establish a methodology that allows the continuation of these studies for the evaluation and a major knowledge of these resources. In this area the evaluation of the fisheries of fish has not been a priority. Some acoustic surveys were made over three years trying to have a contact with the aggregation of Mero in the spawning season. The place selected was the Mahahual beach and the south of Chinchorro Bank Reserve. Many triangular transects were execute from 8 m depth to the end of the talud till 60m. The main hydroacoustic equipments used was the BIOSONICS DT-5000 at a frequency of 130 kHz and BIOSONICS DT-X at 208 kHz that represented a good method to study this specie. The TS (target strength) analysis are giving for different depth stratas, the must quantity of fish with TS between -35 and -20dB were detected in the slopes of 30 and 50 m depth, possibly Mero in spawning. Visual observations from divers reported some individuals Mero and school of different species that are common in this area. No expected concentrations of Mero were found but some fishermen report a high Mero aggregation in January 2001 in Xcalak at south of the surveys.","PeriodicalId":245877,"journal":{"name":"2013 IEEE/OES Acoustics in Underwater Geosciences Symposium","volume":"6 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":"131494815","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":"A hydrophone array calibration method for Multibeam Echo Sounder","authors":"Jia Liu, Feng Xu, Z. Wei, Yahong Xu, Juan Yang, X. An","doi":"10.1109/RIOACOUSTICS.2013.6684009","DOIUrl":"https://doi.org/10.1109/RIOACOUSTICS.2013.6684009","url":null,"abstract":"The side-lobe level is an important factor that determines the performance of the Multibeam Echo Sounders. In order to keep the side-lobes down, the magnitude and phase discrepancies must be compensated prior to the beamforming operation. In this paper, a calibration method of MBES's received array is proposed. This method can be implemented in room other than an open water area., and it doesn't require standard hydrophones or the high precise measurement-equipment. In the paper, a received array of MBES, whose frequency is 200 kHz, is calibrated, and the results have shown that the decreased of the side-lobe level could be as low as 9-12 dB.","PeriodicalId":245877,"journal":{"name":"2013 IEEE/OES Acoustics in Underwater Geosciences Symposium","volume":"46 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":"131128289","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 evolution of offshore survey technology for pipeline inspections","authors":"A. Hoggarth, J. Carballini","doi":"10.1109/RIOACOUSTICS.2013.6683981","DOIUrl":"https://doi.org/10.1109/RIOACOUSTICS.2013.6683981","url":null,"abstract":"The offshore survey industry continues to develop and introduce new technologies. Significant advancements in a variety of technologies have led to the successful introduction of AUV's for a variety of surveying roles. However their impact on the “high end” pipeline inspection is not yet complete. Can AUV's become the standard acquisition platform for pipeline and other inspection surveys or are the challenges and obstacles that prevent the uptake and adoption of AUV technology simply too great? There are now component technologies that, when properly constructed, enable the use of AUV technology for many more survey and inspection related activities. This includes the collection, processing and management of the survey sensor data sets. AUV's are now capable of carrying such sensors as the latest high resolution multibeam sonars, synthetic aperture sonars, high definition cameras and acoustic doppler current profilers. With this array of available acoustic sensors we can expect AUV's to be used for an increasing number of pipeline inspection surveys and other hydrographic survey missions. This increased usage will likely require new data processing workflows and techniques, especially in consideration of the huge data volumes that will require processing once the vehicle returns to its parent ship and data is downloaded. This paper will explore these processing workflows and highlight the challenges and benefits with a view to addressing some key questions and promoting discussion on the future use of AUVs.","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":"132364648","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":"Experimental research on the shallow ambient noise using a single optical fiber vector hydrophone","authors":"Liufang Fu, Shuqing Ma, Yu Chen, Z. Meng, Jianfei Wang","doi":"10.1109/RIOACOUSTICS.2013.6684017","DOIUrl":"https://doi.org/10.1109/RIOACOUSTICS.2013.6684017","url":null,"abstract":"An optical fiber vector hydrophone consists of a three-component optical fiber accelerometer and an omnidirectional pressure hydrophone. It can be used to measure both the scalar and vector components of the ambient noise simultaneously. In order to analyze the characteristics of the ambient vector noise field in shallow water, a sea trial was carried out in the South China Sea in July 2012. The spectra of the ambient noise collected in rainy and sunny weather are compared. The rainfall increases the spectral levels of both scalar and vector components. In addition, the horizontal directionality of the ambient noise is estimated by vector beamforming at four different frequencies of 200, 800, 1000 and 1600 Hz. The estimation results show that the anisotropy of the ambient noise increases with frequency. What's more, the ambient noise is dominant from the open sea in sunny weather, but dominant from all directions in rainy weather. Based on the horizontal directionality of the ambient noise, the theoretical signal-to-noise ratio gains of the X-channel and Y-channel are calculated and compared with the experimental results.","PeriodicalId":245877,"journal":{"name":"2013 IEEE/OES Acoustics in Underwater Geosciences Symposium","volume":"119 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":"133813849","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":"Spectral analysis of littoral water ambient noise in the tropical region","authors":"R. Shastri, Y. Joshi, Arnab Das","doi":"10.1109/RIOACOUSTICS.2013.6683982","DOIUrl":"https://doi.org/10.1109/RIOACOUSTICS.2013.6683982","url":null,"abstract":"Increasing ambient noise levels in the oceans has been a cause of concern due to its impact on sonar performance deployed for military as well as non-military applications as they present sub-optimal behavior in poor SNR conditions. Classical noise filtering techniques offer limited utility in tropical littoral waters because of the random fluctuation of the ambient noise. The repeated surface and bottom interactions of the acoustic signal in littoral waters and diurnal and seasonal variation of the surface parameters of the tropical regions are the reasons of these fluctuations. The paper highlights the challenges in spectral analysis of ambient noise recorded in the tropical littoral waters off the west coast of India in the Arabian Sea for enhancing sonar performance. The spectral analysis aspects attempted in this work include, the power spectral density (PSD) characterization using suitable Probability density function (PDF) fitting tool, the statistical analysis of power spectra using moments obtained from PSD, with respect to diurnal and month wise variations, the spectral comparison presents the difference in low shipping hours and high shipping hours based on local shipping traffic timings and the differentiation of the dominant source of noise namely wind and shipping noise using correlation coefficient as a directive. The analysis has been undertaken in very shallow waters closer to the coast in the west coast of India using multiple sensors placed laterally apart. The timing of the data recording was such that it captured the diurnal environmental variation of a tropical region and also the recording area was closer to a busy port to capture the shipping noise characteristics. Minimal information is available in the open source regarding spectral analysis of the ambient noise in the tropical littoral waters of the Indian coast.","PeriodicalId":245877,"journal":{"name":"2013 IEEE/OES Acoustics in Underwater Geosciences Symposium","volume":"122 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":"121783607","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":"Parallel computing method of seeking 3D eigen-rays with an irregular seabed","authors":"Chuanzhi Xing, Yang Song, Wei Zhang, Qing-xin Meng, S. Piao","doi":"10.1109/RIOACOUSTICS.2013.6683987","DOIUrl":"https://doi.org/10.1109/RIOACOUSTICS.2013.6683987","url":null,"abstract":"In the ocean environment, the internal wave and irregular seabed can cause the ray trace direction reverse in vertical and deflect in horizontal. Therefore the propagation of ray in three dimensional (3D) should be taken into account for long range sound propagation, such as ocean acoustic tomography. The 3D eigen-ray calculation usually is very complex problems and cost long computation time. Though some optimization methods can be applied to decrease computation time, they may lose some computational accuracy. Parallel programming is an important method to improve the speed of multiple data operation at low-cost. A parallel algorithm for 3D eigen-rays searching in waveguide with an irregular seabed is realized based on OpenMP. According to this model, seeking eigen-rays and computation ray tracing and transmission time of eigen-rays are completed. Computing results show that this parallel algorithm performs higher precision and speed with 3.76 speedup ratio in a quad-core CPU. It is hoped that this 3D sound ray model can provide some help in acoustical oceanography research.","PeriodicalId":245877,"journal":{"name":"2013 IEEE/OES Acoustics in Underwater Geosciences Symposium","volume":"19 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":"123318528","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}