Measurement of fish movements at depths to 6000 m using a deep-ocean lander incorporating a short base-line sonar utilizing miniature code-activated transponder technology

Science.gov (United States)

Bagley, P. M.; Bradley, S.; Priede, I. G.; Gray, P.

1999-12-01

Most research on animal behaviour in the deep ocean (to depths of 6000 m) is restricted to the capture of dead specimens or viewing activity over small areas of the sea floor by means of cameras or submersibles. This paper describes the use of a miniature acoustic code-activated transponder (CAT) tag and short base-line sonar to track the movements of deep-sea fish in two dimensions over an area 1 km in diameter centred on a lander platform. The CAT tags and sonar are transported to the deep-sea floor by means of a subsea mooring which is ballasted so that it lands and remains on the sea floor for the duration of the tracking experiment (the lander). A description of the CAT, lander and short base-line sonar is given. Results are presented to illustrate the operation of the system.

Sonar Tank Area

Data.gov (United States)

Federal Laboratory Consortium — The Sonar Tank Facility permits low cost initial 'wet' testing and check out prior to full scale deployment at sea. It can manage controlled conditions calibration...

Adaptive Port-Starboard Beamforming of Triplet Sonar Arrays

NARCIS (Netherlands)

Groen, J.; Beerens, S.P.; Been, R.; Doisy, Y.

2005-01-01

Abstract—For a low-frequency active sonar (LFAS) with a triplet receiver array, it is not clear in advance which signal processing techniques optimize its performance. Here, several advanced beamformers are analyzed theoretically, and the results are compared to experimental data obtained in sea

MSPOT a performance optimisation tool for ASW sonar

NARCIS (Netherlands)

Beerens, S.P.; Benders, F.P.A.

2012-01-01

Several navies are operating or procuring low-frequency active sonar systems (LFAS) as the primary part of their ASW capability. Since LFAS is a relatively new sensor with a performance strongly depending on environmental conditions, the proper operational sensor settings, such as depth and pulse

Digital sonar design in underwater acoustics principles and applications

CERN Document Server

Li, Qihu

2012-01-01

"Digital Sonar Design in Underwater Acoustics Principles and Applications" provides comprehensive and up-to-date coverage of research on sonar design, including the basic theory and techniques of digital signal processing, basic concept of information theory, ocean acoustics, underwater acoustic signal propagation theory, and underwater signal processing theory. This book discusses the general design procedure and approaches to implementation, the design method, system simulation theory and techniques, sonar tests in the laboratory, lake and sea, and practical validation criteria and methods for digital sonar design. It is intended for researchers in the fields of underwater signal processing and sonar design, and also for navy officers and ocean explorers. Qihu Li is a professor at the Institute of Acoustics, Chinese Academy of Sciences, and an academician of the Chinese Academy of Sciences.

Real-Time 3D Sonar Modeling And Visualization

Science.gov (United States)

1998-06-01

looking back towards Manta sonar beam, Manta plus sonar from 1000m off track. 185 NUWC sponsor Erik Chaum Principal investigator Don Brutzman...USN Sonar Officer LT Kevin Byrne USN Intelligence Officer CPT Russell Storms USA Erik Chaum works in NUWC Code 22. He supervised the design and...McGhee, Bob, "The Phoenix Autonomous Underwater Vehicle," chapter 13, AI-BasedMobile Robots, editors David Kortenkamp, Pete Bonasso and Robin Murphy

Bats coordinate sonar and flight behavior as they forage in open and cluttered environments

DEFF Research Database (Denmark)

Falk, Benjamin; Jakobsen, Lasse; Surlykke, Annemarie

2014-01-01

Echolocating bats use active sensing as they emit sounds and listen to the returning echoes to probe their environment for navigation, obstacle avoidance and pursuit of prey. The sensing behavior of bats includes the planning of 3D spatial trajectory paths, which are guided by echo information....... The temporal patterning of sonar sound groups was related to path planning around obstacles in the forest. Together, these results contribute to our understanding of how bats coordinate echolocation and flight behavior to represent and navigate their environment........ In this study, we examined the relationship between active sonar sampling and flight motor output as bats changed environments from open space to an artificial forest in a laboratory flight room. Using high-speed video and audio recordings, we reconstructed and analyzed 3D flight trajectories, sonar beam aim...

Adaptive motion compensation in sonar array processing

NARCIS (Netherlands)

Groen, J.

2006-01-01

In recent years, sonar performance has mainly improved via a significant increase in array ap-erture, signal bandwidth and computational power. This thesis aims at improving sonar array processing techniques based on these three steps forward. In applications such as anti-submarine warfare and mine

Swath sonar mapping of Earth's submarine plate boundaries

Science.gov (United States)

Carbotte, S. M.; Ferrini, V. L.; Celnick, M.; Nitsche, F. O.; Ryan, W. B. F.

2014-12-01

The recent loss of Malaysia Airlines flight MH370 in an area of the Indian Ocean where less than 5% of the seafloor is mapped with depth sounding data (Smith and Marks, EOS 2014) highlights the striking lack of detailed knowledge of the topography of the seabed for much of the worlds' oceans. Advances in swath sonar mapping technology over the past 30 years have led to dramatic improvements in our capability to map the seabed. However, the oceans are vast and only an estimated 10% of the seafloor has been mapped with these systems. Furthermore, the available coverage is highly heterogeneous and focused within areas of national strategic priority and community scientific interest. The major plate boundaries that encircle the globe, most of which are located in the submarine environment, have been a significant focus of marine geoscience research since the advent of swath sonar mapping. While the location of these plate boundaries are well defined from satellite-derived bathymetry, significant regions remain unmapped at the high-resolutions provided by swath sonars and that are needed to study active volcanic and tectonic plate boundary processes. Within the plate interiors, some fossil plate boundary zones, major hotspot volcanoes, and other volcanic provinces have been the focus of dedicated research programs. Away from these major tectonic structures, swath mapping coverage is limited to sparse ocean transit lines which often reveal previously unknown deep-sea channels and other little studied sedimentary structures not resolvable in existing low-resolution global compilations, highlighting the value of these data even in the tectonically quiet plate interiors. Here, we give an overview of multibeam swath sonar mapping of the major plate boundaries of the globe as extracted from public archives. Significant quantities of swath sonar data acquired from deep-sea regions are in restricted-access international archives. Open access to more of these data sets would

Sonar path correction in synthetic aperture processing

NARCIS (Netherlands)

Groen, J.; Hansen, R.E.; Sabel, J.C.

2003-01-01

In the next generation of mine hunting sonars, in particular on Autonomous Underwater Vehicles (AUVs), Synthetic Aperture Sonar (SAS) will play an important role. The benefit of SAS is to increase resolution and signal-tonoise ratio by coherent processing of successive pings. A challenge in SAS is

Side-Scan-Sonar Points for Hudson River, NY

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Side Scan Point Files. These points correspond to individual pings which produced hte side-scan-sonar backscatter imagery. Sonar data were collected November 6 to...

Long range echo classification for minehunting sonars

NARCIS (Netherlands)

Theije, P.A.M. de; Groen, J.; Sabel, J.C.

2006-01-01

This paper focesus on single-ping classification of sea mines, at a range of about 400 m, and combining a hull mounted sonar (HMS) and a propelled variable-depth sonar (PDVS). The deleoped classifier is trained and tested on a set of simulated realistic echoes of mines and non-mines. As the mines

Monitoring upstream sinkhole development by detailed sonar profiling

Energy Technology Data Exchange (ETDEWEB)

Rigbey, S. [Acres International Ltd., Niagara Falls, ON (Canada)

2004-09-01

This paper describes the development and use of a simple sonar system that has been used by engineers for routine monitoring of small sinkholes on the upstream face of a distressed earth dam. Improper construction of the dam led to the development of several sinkholes measuring 10 to 20 m in diameter upstream from the dam which is founded on deep alluvial sands and gravels. The dam has a central core of silt and leakage varies between 200 and 500 l/s, depending on the water level of the reservoir. The main issues with the upstream blanket are: improper fill placement due to the inability to dewater the area properly; omission of a filter material between the blanket and the alluvium foundation; thin placement of fill and runnelling of the blanket prior to impoundment; and, short upstream extent of the blanket. A downstream weighting toe of material was placed to address the seepage and piping that developed immediately following impounding. Other incidents continued over the years, such as downstream sinkholes, slumping of the crest and repairs about 12 years after construction. An inverter filter was also constructed to better control the seepage. Simple bathymetric surveys conducted by sounding the bottom of the reservoir from the ice surface each winter revealed the presence of several large sinkholes. Although infilling programs were conducted, sinkholes redeveloped after each program. The bathymetric surveys were found to be limited in accuracy and repeatability. Therefore, it was not possible to monitor small developments on a yearly basis. A 3-dimensional seepage model was developed to reconcile some of the unexplained piezometric patterns and to better understand the seepage patterns. However, this was also unsuccessful on its own. A trial sonar survey was then undertaken in 2002 by a Vancouver-based sonar company using an Imagenix profiling sonar head. It was successful in locating a small, previously unknown sinkhole measuring a few metres in diameter at

Review of research on sonar imaging technology in China

Science.gov (United States)

Guo, Haitao; Li, Renping; Xu, Feng; Liu, Liyuan

2013-11-01

Over the past 20 years, sonar imaging technology particularly for the high-technology sector has been a focus of research, in which many developed countries, especially those with coast lines, have been competing with each other. It has seen a rapid development with increasing widespread applications that has played an important and irreplaceable role in underwater exploration with great prospects for social, economic, scientific, and military benefits. The fundamental techniques underlying sonar imaging, including multi-beamforming, synthetic-aperture and inverse synthetic-aperture sonar, acoustic lensing, and acoustical holography, are described in this paper. This is followed by a comprehensive and systematic review on the advantages and disadvantages of these imaging techniques, applicability conditions, development trends, new ideas, new methods, and improvements in old methods over recent years with an emphasis on the situation in China, along with a bold and constructive prediction to some development characteristics of sonar imaging technology in the near future in China. The perspectives presented in this paper are offered with the idea of providing some degree of guidance and promotion of research on sonar imaging technology.

Sperm whales reduce foraging effort during exposure to 1-2 kHz sonar and killer whale sounds.

Science.gov (United States)

Isojunno, Saana; Cure, Charlotte; Kvadsheim, Petter Helgevold; Lam, Frans-Peter Alexander; Tyack, Peter Lloyd; Wensveen, Paul Jacobus; Miller, Patrick James O'Malley

2016-01-01

The time and energetic costs of behavioral responses to incidental and experimental sonar exposures, as well as control stimuli, were quantified using hidden state analysis of time series of acoustic and movement data recorded by tags (DTAG) attached to 12 sperm whales (Physeter macrocephalus) using suction cups. Behavioral state transition modeling showed that tagged whales switched to a non-foraging, non-resting state during both experimental transmissions of low-frequency active sonar from an approaching vessel (LFAS; 1-2 kHz, source level 214 dB re 1 µPa m, four tag records) and playbacks of potential predator (killer whale, Orcinus orca) sounds broadcast at naturally occurring sound levels as a positive control from a drifting boat (five tag records). Time spent in foraging states and the probability of prey capture attempts were reduced during these two types of exposures with little change in overall locomotion activity, suggesting an effect on energy intake with no immediate compensation. Whales switched to the active non-foraging state over received sound pressure levels of 131-165 dB re 1 µPa during LFAS exposure. In contrast, no changes in foraging behavior were detected in response to experimental negative controls (no-sonar ship approach or noise control playback) or to experimental medium-frequency active sonar exposures (MFAS; 6-7 kHz, source level 199 re 1 µPa m, received sound pressure level [SPL] = 73-158 dB re 1 µPa). Similarly, there was no reduction in foraging effort for three whales exposed to incidental, unidentified 4.7-5.1 kHz sonar signals received at lower levels (SPL = 89-133 dB re 1 µPa). These results demonstrate that similar to predation risk, exposure to sonar can affect functional behaviors, and indicate that increased perception of risk with higher source level or lower frequency may modulate how sperm whales respond to anthropogenic sound.

Passive Sonar Target Detection Using Statistical Classifier and Adaptive Threshold

Directory of Open Access Journals (Sweden)

Hamed Komari Alaie

2018-01-01

Full Text Available This paper presents the results of an experimental investigation about target detecting with passive sonar in Persian Gulf. Detecting propagated sounds in the water is one of the basic challenges of the researchers in sonar field. This challenge will be complex in shallow water (like Persian Gulf and noise less vessels. Generally, in passive sonar, the targets are detected by sonar equation (with constant threshold that increases the detection error in shallow water. The purpose of this study is proposed a new method for detecting targets in passive sonars using adaptive threshold. In this method, target signal (sound is processed in time and frequency domain. For classifying, Bayesian classification is used and posterior distribution is estimated by Maximum Likelihood Estimation algorithm. Finally, target was detected by combining the detection points in both domains using Least Mean Square (LMS adaptive filter. Results of this paper has showed that the proposed method has improved true detection rate by about 24% when compared other the best detection method.

The Method of a Standalone Functional Verifying Operability of Sonar Control Systems

Directory of Open Access Journals (Sweden)

A. A. Sotnikov

2014-01-01

Full Text Available This article describes a method of standalone verifying sonar control system, which is based on functional checking of control system operability.The main features of realized method are a development of the valid mathematic model for simulation of sonar signals at the point of hydroacoustic antenna, a valid representation of the sonar control system modes as a discrete Markov model, providing functional object verification in real time mode.Some ways are proposed to control computational complexity in case of insufficient computing resources of the simulation equipment, namely the way of model functionality reduction and the way of adequacy reduction.Experiments were made using testing equipment, which was developed by department of Research Institute of Information Control System at Bauman Moscow State Technical University to verify technical validity of industrial sonar complexes.On-board software was artificially changed to create malfunctions in functionality of sonar control systems during the verifying process in order to estimate verifying system performances.The method efficiency was proved by the theory and experiment results in comparison with the basic methodology of verifying technical systems.This method could be also used in debugging of on-board software of sonar complexes and in development of new promising algorithms of sonar signal processing.

Digital Signal Processing Applied to the Modernization Of Polish Navy Sonars

Directory of Open Access Journals (Sweden)

Marszal Jacek

2014-04-01

Full Text Available The article presents the equipment and digital signal processing methods used for modernizing the Polish Navy’s sonars. With the rapid advancement of electronic technologies and digital signal processing methods, electronic systems, including sonars, become obsolete very quickly. In the late 1990s a team of researchers of the Department of Marine Electronics Systems, Faculty of Electronics, Telecommunications and Informatics, Gdansk University of Technology, began work on modernizing existing sonar systems for the Polish Navy. As part of the effort, a methodology of sonar modernization was implemented involving a complete replacement of existing electronic components with newly designed ones by using bespoke systems and methods of digital signal processing. Large and expensive systems of ultrasound transducers and their dipping and stabilisation systems underwent necessary repairs but were otherwise left unchanged. As a result, between 2001 and 2014 the Gdansk University of Technology helped to modernize 30 sonars of different types.

A Study for Optimum Survey Method of Underwater Structure Using the Dual Sonar Sensor

Directory of Open Access Journals (Sweden)

Youngseok Kim

2017-01-01

Full Text Available We have developed dual sonar equipment and an improved operating method for improving resolution in order to solve the problems of limitations of the optical equipment and the application method of SSS (side scan sonar in the investigation of damage of underwater structures. We analyzed the influence factors of the resolution of sonar data through the comparison of resolution and data quality in indoor test. Also we confirmed the problems about the overlapping area of the dual sonar. Depth and distance were analyzed as major influencing factors for survey angle. Specimens were scanned while adjusting distance and towfish angle according to depth change in order to verify applicability of the developed dual sonar in the field experiment. Optimal resolution was found to be 3 cm in specimen spacing, and 20 sample data items were extracted. We developed the regression model based on the multiple regression analysis and developed the RealDualSONAR-DAQ tool, the dual sonar optimum operating method program based on proposed correlation equations. We can use the developed tools to get the value of the major influencing factors for dual sonar operation and obtain high quality sonar data to analyze damage of underwater structures.

Tongue-driven sonar beam steering by a lingual-echolocating fruit bat.

Directory of Open Access Journals (Sweden)

Wu-Jung Lee

2017-12-01

Full Text Available Animals enhance sensory acquisition from a specific direction by movements of head, ears, or eyes. As active sensing animals, echolocating bats also aim their directional sonar beam to selectively "illuminate" a confined volume of space, facilitating efficient information processing by reducing echo interference and clutter. Such sonar beam control is generally achieved by head movements or shape changes of the sound-emitting mouth or nose. However, lingual-echolocating Egyptian fruit bats, Rousettus aegyptiacus, which produce sound by clicking their tongue, can dramatically change beam direction at very short temporal intervals without visible morphological changes. The mechanism supporting this capability has remained a mystery. Here, we measured signals from free-flying Egyptian fruit bats and discovered a systematic angular sweep of beam focus across increasing frequency. This unusual signal structure has not been observed in other animals and cannot be explained by the conventional and widely-used "piston model" that describes the emission pattern of other bat species. Through modeling, we show that the observed beam features can be captured by an array of tongue-driven sound sources located along the side of the mouth, and that the sonar beam direction can be steered parsimoniously by inducing changes to the pattern of phase differences through moving tongue location. The effects are broadly similar to those found in a phased array-an engineering design widely found in human-made sonar systems that enables beam direction changes without changes in the physical transducer assembly. Our study reveals an intriguing parallel between biology and human engineering in solving problems in fundamentally similar ways.

Water Column Sonar Data Collection

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The collection and analysis of water column sonar data is a relatively new avenue of research into the marine environment. Primary uses include assessing biological...

Multiresolution 3-D reconstruction from side-scan sonar images.

Science.gov (United States)

Coiras, Enrique; Petillot, Yvan; Lane, David M

2007-02-01

In this paper, a new method for the estimation of seabed elevation maps from side-scan sonar images is presented. The side-scan image formation process is represented by a Lambertian diffuse model, which is then inverted by a multiresolution optimization procedure inspired by expectation-maximization to account for the characteristics of the imaged seafloor region. On convergence of the model, approximations for seabed reflectivity, side-scan beam pattern, and seabed altitude are obtained. The performance of the system is evaluated against a real structure of known dimensions. Reconstruction results for images acquired by different sonar sensors are presented. Applications to augmented reality for the simulation of targets in sonar imagery are also discussed.

NPS ARIES Forward Look Sonar Integration

National Research Council Canada - National Science Library

Healey, A. J; Horner, D. P

2004-01-01

This work integrated an experimental Blazed Array Forward Looking Sonar (FLS) developed by the University of Washington, Applied Physics Laboratories into the ARIES autonomous underwater vehicle (AUV...

A Mobile Robot Sonar System with Obstacle Avoidance.

Science.gov (United States)

1994-03-01

WITH OBSTACLE - AVOIDANCE __ by __ Patrick Gerard Byrne March 1994 Thesis Advisor : Yutaka Kanayama Approved for public release; distribution is...point p is on a line L whose normal has an orientation a and whose distance from the origin is r (Figure 5). This method has an advantage in expressing...sonar(FRONTR); Wine(&pl); while(hitl I >’- 100.0 11 hitl 1 - 0.0 ){ hitl I = sonar(FRONTR); I skipO; line(&p3); gat- robO (&posit 1); while(positl.x

Prospects for using sonar for underwater archeology on the Yenisei: surveying a 19th century shipwreck

Science.gov (United States)

Goncharov, A. E.; Mednikov, D. M.; Karelin, N. M.; Nasyrov, I. R.

2016-11-01

Current progress in underwater archeology is based on a rich arsenal of high-tech appliances, among which sonar technology plays a key role; it enables scientists not only to detect submerged archeological objects, but to examine them in high definition without having to conduct diving operations or use expensive underwater unmanned vehicles. While the majority of sensational scientific discoveries using sonar have been made in saltwater environments, freshwater ones, rivers in particular, have seen limited activity. The river Yenisei in central Siberia contains an unrecorded number of shipwrecks that await being discovered and studied. In this article we focus on the peculiarities of using sonar for detecting archeological sites on the Yenisei. This article is based on the results of the 2016 expedition, which has determined the location of Thames, a 19th century British steam schooner which was wrecked on the Yenisei.

Airborne Low-Frequency Sonar (ALFS) Lab

Data.gov (United States)

Federal Laboratory Consortium — The ALFS lab is dedicated to support acoustic data analysis and processing software support to the AN/AQS-22 dipping sonar system. It includes stand-alone Software...

Monitoring the US ATLAS Network Infrastructure with perfSONAR-PS

CERN Document Server

McKee, S; The ATLAS collaboration; Laurens, P; Severini, H; Wlodek, T; Wolff, S; Zurawski, J

2012-01-01

We will present our motivations for deploying and using the perfSONAR-PS Performance Toolkit at ATLAS sites in the United States and describe our experience in using it. This software creates a dedicated monitoring server, capable of collecting and performing a wide range of passive and active network measurements. Each independent instance is managed locally, but able to federate on a global scale; enabling a full view of the network infrastructure that spans domain boundaries. This information, available through web service interfaces, can easily be retrieved to create customized applications. USATLAS has developed a centralized “dashboard” offering network administrators, users, and decision makers the ability to see the performance of the network at a glance. The dashboard framework includes the ability to notify users (alarm) when problems are found, thus allowing rapid response to potential problems and making perfSONAR-PS crucial to the operation of our distributed computing infrastructure.

Cleaning Massive Sonar Point Clouds

DEFF Research Database (Denmark)

Arge, Lars Allan; Larsen, Kasper Green; Mølhave, Thomas

2010-01-01

We consider the problem of automatically cleaning massive sonar data point clouds, that is, the problem of automatically removing noisy points that for example appear as a result of scans of (shoals of) fish, multiple reflections, scanner self-reflections, refraction in gas bubbles, and so on. We...

A micro-Doppler sonar for acoustic surveillance in sensor networks

Science.gov (United States)

Zhang, Zhaonian

Wireless sensor networks have been employed in a wide variety of applications, despite the limited energy and communication resources at each sensor node. Low power custom VLSI chips implementing passive acoustic sensing algorithms have been successfully integrated into an acoustic surveillance unit and demonstrated for detection and location of sound sources. In this dissertation, I explore active and passive acoustic sensing techniques, signal processing and classification algorithms for detection and classification in a multinodal sensor network environment. I will present the design and characterization of a continuous-wave micro-Doppler sonar to image objects with articulated moving components. As an example application for this system, we use it to image gaits of humans and four-legged animals. I will present the micro-Doppler gait signatures of a walking person, a dog and a horse. I will discuss the resolution and range of this micro-Doppler sonar and use experimental results to support the theoretical analyses. In order to reduce the data rate and make the system amenable to wireless sensor networks, I will present a second micro-Doppler sonar that uses bandpass sampling for data acquisition. Speech recognition algorithms are explored for biometric identifications from one's gait, and I will present and compare the classification performance of the two systems. The acoustic micro-Doppler sonar design and biometric identification results are the first in the field as the previous work used either video camera or microwave technology. I will also review bearing estimation algorithms and present results of applying these algorithms for bearing estimation and tracking of moving vehicles. Another major source of the power consumption at each sensor node is the wireless interface. To address the need of low power communications in a wireless sensor network, I will also discuss the design and implementation of ultra wideband transmitters in a three dimensional

Implementation of Signal Processing in Stereo-Scopic Active Sonar Using Heterodyne System

Directory of Open Access Journals (Sweden)

BOKHARI Syed Umar

2012-10-01

Full Text Available “SONAR” is an acronym for sound ranging and navigation. It uses sound waves to detect an object in the surroundings and calculate its distance. This device has a very important applications in shipbuilding industry and military systems. Moreover it’s also being extensively used in deep sea research of new species of plants and minerals, where it is practically impossible for humans to go. The most important feature of this system is the usage of ultrasonicfrequency to detect objects that are important for data collection or detection. Transmitting an ultra sonic frequency using an electronic oscillator is not a very difficult task, the real challenge is to design a reciever that could carry out a particular modulation technique to convert an ultra-sonic frequency to an audiblefrequency. In this paper, we propose aseteroscopic active SONAR proto-type. Further, we performed a seriers of expeirments using modulation techniques. The results obtained from the experiments gives us a braod understanding of the different behaviour of asignal.

Reliability of fish size estimates obtained from multibeam imaging sonar

Science.gov (United States)

Hightower, Joseph E.; Magowan, Kevin J.; Brown, Lori M.; Fox, Dewayne A.

2013-01-01

Multibeam imaging sonars have considerable potential for use in fisheries surveys because the video-like images are easy to interpret, and they contain information about fish size, shape, and swimming behavior, as well as characteristics of occupied habitats. We examined images obtained using a dual-frequency identification sonar (DIDSON) multibeam sonar for Atlantic sturgeon Acipenser oxyrinchus oxyrinchus, striped bass Morone saxatilis, white perch M. americana, and channel catfish Ictalurus punctatus of known size (20–141 cm) to determine the reliability of length estimates. For ranges up to 11 m, percent measurement error (sonar estimate – total length)/total length × 100 varied by species but was not related to the fish's range or aspect angle (orientation relative to the sonar beam). Least-square mean percent error was significantly different from 0.0 for Atlantic sturgeon (x̄  =  −8.34, SE  =  2.39) and white perch (x̄  = 14.48, SE  =  3.99) but not striped bass (x̄  =  3.71, SE  =  2.58) or channel catfish (x̄  = 3.97, SE  =  5.16). Underestimating lengths of Atlantic sturgeon may be due to difficulty in detecting the snout or the longer dorsal lobe of the heterocercal tail. White perch was the smallest species tested, and it had the largest percent measurement errors (both positive and negative) and the lowest percentage of images classified as good or acceptable. Automated length estimates for the four species using Echoview software varied with position in the view-field. Estimates tended to be low at more extreme azimuthal angles (fish's angle off-axis within the view-field), but mean and maximum estimates were highly correlated with total length. Software estimates also were biased by fish images partially outside the view-field and when acoustic crosstalk occurred (when a fish perpendicular to the sonar and at relatively close range is detected in the side lobes of adjacent beams). These sources of

Selection of a Suitable Wall Pressure Spectrum Model for Estimating Flow-Induced Noise in Sonar Applications

Directory of Open Access Journals (Sweden)

V. Bhujanga Rao

1995-01-01

Full Text Available Flow-induced structural noise of a sonar dome in which the sonar transducer is housed, constitutes a major source of self-noise above a certain speed of the vessel. Excitation of the sonar dome structure by random pressure fluctuations in turbulent boundary layer flow leads to acoustic radiation into the interior of the dome. This acoustic radiation is termed flow-induced structural noise. Such noise contributes significantly to sonar self-noise of submerged vessels cruising at high speed and plays an important role in surface ships, torpedos, and towed sonars as well. Various turbulent boundary layer wall pressure models published were analyzed and the most suitable analytical model for the sonar dome application selected while taking into account high frequency, fluid loading, low wave number contribution, and pressure gradient effects. These investigations included type of coupling that exists between turbulent boundary layer pressure fluctuations and dome wall structure of a typical sonar dome. Comparison of theoretical data with measured data onboard a ship are also reported.

Mid-Frequency Sonar Interactions with Beaked Whales

National Research Council Canada - National Science Library

Foote, Kenneth G; Feijoo, Gonzalo R; Rye, Kent; Reidenberg, Joy; Hastings, Mardi

2007-01-01

The top-level goal of this project is to build an interactive online modeling and visualization system, called the Virtual Beaked Whale, to enable users to predict mid-frequency sonar-induced acoustic...

A novel approach to surveying sturgeon using side-scan sonar and occupancy modeling

Science.gov (United States)

Flowers, H. Jared; Hightower, Joseph E.

2013-01-01

Technological advances represent opportunities to enhance and supplement traditional fisheries sampling approaches. One example with growing importance for fisheries research is hydroacoustic technologies such as side-scan sonar. Advantages of side-scan sonar over traditional techniques include the ability to sample large areas efficiently and the potential to survey fish without physical handling-important for species of conservation concern, such as endangered sturgeons. Our objectives were to design an efficient survey methodology for sampling Atlantic Sturgeon Acipenser oxyrinchus by using side-scan sonar and to developmethods for analyzing these data. In North Carolina and South Carolina, we surveyed six rivers thought to contain varying abundances of sturgeon by using a combination of side-scan sonar, telemetry, and video cameras (i.e., to sample jumping sturgeon). Lower reaches of each river near the saltwater-freshwater interface were surveyed on three occasions (generally successive days), and we used occupancy modeling to analyze these data.We were able to detect sturgeon in five of six rivers by using these methods. Side-scan sonar was effective in detecting sturgeon, with estimated gear-specific detection probabilities ranging from 0.2 to 0.5 and river-specific occupancy estimates (per 2-km river segment) ranging from 0.0 to 0.8. Future extensions of this occupancy modeling framework will involve the use of side-scan sonar data to assess sturgeon habitat and abundance in different river systems.

An integrated environment for fast development and performance assessment of sonar image processing algorithms - SSIE

DEFF Research Database (Denmark)

Henriksen, Lars

1996-01-01

The sonar simulator integrated environment (SSIE) is a tool for developing high performance processing algorithms for single or sequences of sonar images. The tool is based on MATLAB providing a very short lead time from concept to executable code and thereby assessment of the algorithms tested...... of the algorithms is the availability of sonar images. To accommodate this problem the SSIE has been equipped with a simulator capable of generating high fidelity sonar images for a given scene of objects, sea-bed AUV path, etc. In the paper the main components of the SSIE is described and examples of different...... processing steps are given...

A novel underwater dam crack detection and classification approach based on sonar images.

Science.gov (United States)

Shi, Pengfei; Fan, Xinnan; Ni, Jianjun; Khan, Zubair; Li, Min

2017-01-01

Underwater dam crack detection and classification based on sonar images is a challenging task because underwater environments are complex and because cracks are quite random and diverse in nature. Furthermore, obtainable sonar images are of low resolution. To address these problems, a novel underwater dam crack detection and classification approach based on sonar imagery is proposed. First, the sonar images are divided into image blocks. Second, a clustering analysis of a 3-D feature space is used to obtain the crack fragments. Third, the crack fragments are connected using an improved tensor voting method. Fourth, a minimum spanning tree is used to obtain the crack curve. Finally, an improved evidence theory combined with fuzzy rule reasoning is proposed to classify the cracks. Experimental results show that the proposed approach is able to detect underwater dam cracks and classify them accurately and effectively under complex underwater environments.

A novel underwater dam crack detection and classification approach based on sonar images.

Directory of Open Access Journals (Sweden)

Pengfei Shi

Full Text Available Underwater dam crack detection and classification based on sonar images is a challenging task because underwater environments are complex and because cracks are quite random and diverse in nature. Furthermore, obtainable sonar images are of low resolution. To address these problems, a novel underwater dam crack detection and classification approach based on sonar imagery is proposed. First, the sonar images are divided into image blocks. Second, a clustering analysis of a 3-D feature space is used to obtain the crack fragments. Third, the crack fragments are connected using an improved tensor voting method. Fourth, a minimum spanning tree is used to obtain the crack curve. Finally, an improved evidence theory combined with fuzzy rule reasoning is proposed to classify the cracks. Experimental results show that the proposed approach is able to detect underwater dam cracks and classify them accurately and effectively under complex underwater environments.

A Spatial Reference Grid for Real-Time Autonomous Underwater Modeling using 3-D Sonar

Energy Technology Data Exchange (ETDEWEB)

Auran, P.G.

1996-12-31

The offshore industry has recognized the need for intelligent underwater robotic vehicles. This doctoral thesis deals with autonomous underwater vehicles (AUVs) and concentrates on a data representation for real-time image formation and analysis. Its main objective is to develop a 3-D image representation suitable for autonomous perception objectives underwater, assuming active sonar as the main sensor for perception. The main contributions are: (1) A dynamical image representation for 3-D range data, (2) A basic electronic circuit and software system for 3-D sonar sampling and amplitude thresholding, (3) A model for target reliability, (4) An efficient connected components algorithm for 3-D segmentation, (5) A method for extracting general 3-D geometrical representations from segmented echo clusters, (6) Experimental results of planar and curved target modeling. 142 refs., 120 figs., 10 tabs.

Sonar backscatter differentiation of dominant macrohabitat types in a hydrothermal vent field.

Science.gov (United States)

Durand, Sébastien; Legendre, Pierre; Juniper, S Kim

2006-08-01

Over the past 20 years, sonar remote sensing has opened ways of acquiring new spatial information on seafloor habitat and ecosystem properties. While some researchers are presently working to improve sonar methods so that broad-scale high-definition surveys can be effectively conducted for management purposes, others are trying to use these surveying techniques in more local areas. Because ecosystem management is scale-dependent, there is a need to acquire spatiotemporal knowledge over various scales to bridge the gap between already-acquired point-source data and information available at broader scales. Using a 675-kHz single-pencil-beam sonar mounted on the remotely operated vehicle ROPOS, 2200 m deep on the Juan de Fuca Ridge, East Pacific Rise, five dominant habitat types located in a hydrothermal vent field were identified and characterized by their sonar signatures. The data, collected at different altitudes from 1 to 10 m above the seafloor, were depth-normalized. We compared three ways of handling the echoes embedded in the backscatters to detect and differentiate the five habitat types; we examined the influence of footprint size on the discrimination capacity of the three methods; and we identified key variables, derived from echoes that characterize each habitat type. The first method used a set of variables describing echo shapes, and the second method used as variables the power intensity values found within the echoes, whereas the last method combined all these variables. Canonical discriminant analysis was used to discriminate among the five habitat types using the three methods. The discriminant models were constructed using 70% of the data while the remaining 30% were used for validation. The results showed that footprints 20-30 cm in diameter included a sufficient amount of spatial variation to make the sonar signatures sensitive to the habitat types, producing on average 82% correct classification. Smaller footprints produced lower percentages of

Probability-Based Recognition Framework for Underwater Landmarks Using Sonar Images †.

Science.gov (United States)

Lee, Yeongjun; Choi, Jinwoo; Ko, Nak Yong; Choi, Hyun-Taek

2017-08-24

This paper proposes a probability-based framework for recognizing underwater landmarks using sonar images. Current recognition methods use a single image, which does not provide reliable results because of weaknesses of the sonar image such as unstable acoustic source, many speckle noises, low resolution images, single channel image, and so on. However, using consecutive sonar images, if the status-i.e., the existence and identity (or name)-of an object is continuously evaluated by a stochastic method, the result of the recognition method is available for calculating the uncertainty, and it is more suitable for various applications. Our proposed framework consists of three steps: (1) candidate selection, (2) continuity evaluation, and (3) Bayesian feature estimation. Two probability methods-particle filtering and Bayesian feature estimation-are used to repeatedly estimate the continuity and feature of objects in consecutive images. Thus, the status of the object is repeatedly predicted and updated by a stochastic method. Furthermore, we develop an artificial landmark to increase detectability by an imaging sonar, which we apply to the characteristics of acoustic waves, such as instability and reflection depending on the roughness of the reflector surface. The proposed method is verified by conducting basin experiments, and the results are presented.

Real-time underwater object detection based on an electrically scanned high-resolution sonar

DEFF Research Database (Denmark)

Henriksen, Lars

1994-01-01

The paper describes an approach to real time detection and tracking of underwater objects, using image sequences from an electrically scanned high-resolution sonar. The use of a high resolution sonar provides a good estimate of the location of the objects, but strains the computers on board, beca...

HULU SUNGAI PERAK BED SEDIMENT MAPPING USING UNDERWATER ACOUSTIC SONAR

Directory of Open Access Journals (Sweden)

N. Arriafdi

2016-09-01

Full Text Available Development in acoustic survey techniques in particular side scan sonar have revolutionized the way we are able to image, map and understand the riverbed environment. It is now cost effective to image large areas of the riverbed using these techniques and the backscatter image created from surveys provides base line data from which thematic maps of the riverbed environment including maps of morphological geology, can be derived when interpreted in conjunction with in situ sampling data. This article focuses on investigation characteristics of sediments and correlation of side scan backscatter image with signal strength. The interpretation of acoustic backscatter rely on experienced interpretation by eye of grey scale images produced from the data. A 990F Starfish Side Scan Sonar was used to collect and develop a series of sonar images along 6 km of Hulu Sungai Perak. Background sediments could be delineated accurately and the image textures could be linked to the actual river floor appearance through grab sampling. A major difference was found in the acoustic returns from the two research area studies: the upstream area shows much rougher textures. This is due to an actual differences in riverbed roughness, caused by a difference in bottom currents and sediment dynamics in the two areas. The highest backscatter correlates with coarsest and roughness sediment. Result suggest that image based backscatter classification shows considerable promise for interpretation of side scan sonar data for the production of geological maps.

Textural Segmentation of High-Resolution Sidescan Sonar Images

National Research Council Canada - National Science Library

Kalcic, Maria; Bibee, Dale

1995-01-01

.... The high resolution of the 455 kHz sonar imagery also provides much information about the surficial bottom sediments, however their acoustic scattering properties are not well understood at high frequencies...

Recent Developments in SOBEK Passive Sonar Technology

NARCIS (Netherlands)

Hunter, A.J.; Fillinger, L.; Zampolli, M.; Clarijs, M.C.

2012-01-01

Surveillance of waterside locations for protection against threats from small fast surface vessels and underwater intruders is a very relevant but challenging problem. For this reason, the Netherlands Organisation for Applied Scientific Research (TNO) is developing SOBEK – a family of passive sonar

Sensor Fusion - Sonar and Stereo Vision, Using Occupancy Grids and SIFT

DEFF Research Database (Denmark)

Plascencia, Alfredo; Bendtsen, Jan Dimon

2006-01-01

to the occupied and empty regions. SIFT (Scale Invariant Feature Transform) feature descriptors are  interpreted using gaussian probabilistic error models. The use of occupancy grids is proposed for representing the sonar  as well as the features descriptors readings. The Bayesian estimation approach is applied...... to update the sonar and the SIFT descriptors' uncertainty grids. The sensor fusion yields a significant reduction in the uncertainty of the occupancy grid compared to the individual sensor readings....

Development of Discrete Power Supply with Charge Pump Method for High Powered Sonar System

Directory of Open Access Journals (Sweden)

Kristian Ismail

2012-07-01

Full Text Available Power supply is one of the electronic devices that can provide electric energy for electronic systems or other systems. There are several types of power supplies that can be applied depend on the requirement and functions. One example is the use of power supply for sonar systems. Sonar system is a device which can be used to detect a target under water. The sonar system is an electronic circuit that requires a power supply with specific characteristics when the sonar functions as a transmitter and a receiver in the specific span time (when on and the specific lag time (when off. This paper discusses the design of power supply for high-powered sonar systems with discrete methods in which high power supply is only applied when the acoustic waves radiated under water. Charge pump was used to get the appropriate output voltage from lower input voltage. Charge pump utilized a combination of series and parallel connections of capacitors. The working mode of this power supply used the lag time as the calculation of time to charge charge pump capacitors in parallel while the span time was used for the calculation of discharging the charge pump capacitors in series.

Biologically-inspired radar and sonar lessons from nature

CERN Document Server

Balleri, Alessio; Baker, Chris

2017-01-01

This book presents some of the recent work that has been carried out to investigate how sophisticated sensing techniques used in nature can be applied to radar and sonar systems to improve their performance.

SONAR: A High-Throughput Pipeline for Inferring Antibody Ontogenies from Longitudinal Sequencing of B Cell Transcripts.

Science.gov (United States)

Schramm, Chaim A; Sheng, Zizhang; Zhang, Zhenhai; Mascola, John R; Kwong, Peter D; Shapiro, Lawrence

2016-01-01

The rapid advance of massively parallel or next-generation sequencing technologies has made possible the characterization of B cell receptor repertoires in ever greater detail, and these developments have triggered a proliferation of software tools for processing and annotating these data. Of especial interest, however, is the capability to track the development of specific antibody lineages across time, which remains beyond the scope of most current programs. We have previously reported on the use of techniques such as inter- and intradonor analysis and CDR3 tracing to identify transcripts related to an antibody of interest. Here, we present Software for the Ontogenic aNalysis of Antibody Repertoires (SONAR), capable of automating both general repertoire analysis and specialized techniques for investigating specific lineages. SONAR annotates next-generation sequencing data, identifies transcripts in a lineage of interest, and tracks lineage development across multiple time points. SONAR also generates figures, such as identity-divergence plots and longitudinal phylogenetic "birthday" trees, and provides interfaces to other programs such as DNAML and BEAST. SONAR can be downloaded as a ready-to-run Docker image or manually installed on a local machine. In the latter case, it can also be configured to take advantage of a high-performance computing cluster for the most computationally intensive steps, if available. In summary, this software provides a useful new tool for the processing of large next-generation sequencing datasets and the ontogenic analysis of neutralizing antibody lineages. SONAR can be found at https://github.com/scharch/SONAR, and the Docker image can be obtained from https://hub.docker.com/r/scharch/sonar/.

Side-Scan-Sonar Lines for Hudson River, NY

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Side Scan Sonar and Subbottom Profiler Tracklines. Data was collected November 5 to December 15, 2009, in the estuary north from Saugerties to Troy. Fugro utilized...

Bathymetry mapping using a GPS-sonar equipped remote control boat: Application in waste stabilisation ponds

Science.gov (United States)

Coggins, Liah; Ghadouani, Anas; Ghisalberti, Marco

2014-05-01

Traditionally, bathymetry mapping of ponds, lakes and rivers have used techniques which are low in spatial resolution, sometimes subjective in terms of precision and accuracy, labour intensive, and that require a high level of safety precautions. In waste stabilisation ponds (WSP) in particular, sludge heights, and thus sludge volume, are commonly measured using a sludge judge (a clear plastic pipe with length markings). A remote control boat fitted with a GPS-equipped sonar unit can improve the resolution of depth measurements, and reduce safety and labour requirements. Sonar devices equipped with GPS technology, also known as fish finders, are readily available and widely used by people in boating. Through the use of GPS technology in conjunction with sonar, the location and depth can be recorded electronically onto a memory card. However, despite its high applicability to the field, this technology has so far been underutilised. In the case of WSP, the sonar can measure the water depth to the top of the sludge layer, which can then be used to develop contour maps of sludge distribution and to determine sludge volume. The coupling of sonar technology with a remotely operative vehicle has several advantages of traditional measurement techniques, particularly in removing human subjectivity of readings, and the sonar being able to collect more data points in a shorter period of time, and continuously, with a much higher spatial resolution. The GPS-sonar equipped remote control boat has been tested on in excess of 50 WSP within Western Australia, and has shown a very strong correlation (R2 = 0.98) between spot readings taken with the sonar compared to a sludge judge. This has shown that the remote control boat with GPS-sonar device is capable of providing sludge bathymetry with greatly increased spatial resolution, while greatly reducing profiling time. Remotely operated vehicles, such as the one built in this study, are useful for not only determining sludge

PMHT Approach for Multi-Target Multi-Sensor Sonar Tracking in Clutter.

Science.gov (United States)

Li, Xiaohua; Li, Yaan; Yu, Jing; Chen, Xiao; Dai, Miao

2015-11-06

Multi-sensor sonar tracking has many advantages, such as the potential to reduce the overall measurement uncertainty and the possibility to hide the receiver. However, the use of multi-target multi-sensor sonar tracking is challenging because of the complexity of the underwater environment, especially the low target detection probability and extremely large number of false alarms caused by reverberation. In this work, to solve the problem of multi-target multi-sensor sonar tracking in the presence of clutter, a novel probabilistic multi-hypothesis tracker (PMHT) approach based on the extended Kalman filter (EKF) and unscented Kalman filter (UKF) is proposed. The PMHT can efficiently handle the unknown measurements-to-targets and measurements-to-transmitters data association ambiguity. The EKF and UKF are used to deal with the high degree of nonlinearity in the measurement model. The simulation results show that the proposed algorithm can improve the target tracking performance in a cluttered environment greatly, and its computational load is low.

An Improved Azimuth Angle Estimation Method with a Single Acoustic Vector Sensor Based on an Active Sonar Detection System.

Science.gov (United States)

Zhao, Anbang; Ma, Lin; Ma, Xuefei; Hui, Juan

2017-02-20

In this paper, an improved azimuth angle estimation method with a single acoustic vector sensor (AVS) is proposed based on matched filtering theory. The proposed method is mainly applied in an active sonar detection system. According to the conventional passive method based on complex acoustic intensity measurement, the mathematical and physical model of this proposed method is described in detail. The computer simulation and lake experiments results indicate that this method can realize the azimuth angle estimation with high precision by using only a single AVS. Compared with the conventional method, the proposed method achieves better estimation performance. Moreover, the proposed method does not require complex operations in frequencydomain and achieves computational complexity reduction.

An Improved Azimuth Angle Estimation Method with a Single Acoustic Vector Sensor Based on an Active Sonar Detection System

Directory of Open Access Journals (Sweden)

Anbang Zhao

2017-02-01

Full Text Available In this paper, an improved azimuth angle estimation method with a single acoustic vector sensor (AVS is proposed based on matched filtering theory. The proposed method is mainly applied in an active sonar detection system. According to the conventional passive method based on complex acoustic intensity measurement, the mathematical and physical model of this proposed method is described in detail. The computer simulation and lake experiments results indicate that this method can realize the azimuth angle estimation with high precision by using only a single AVS. Compared with the conventional method, the proposed method achieves better estimation performance. Moreover, the proposed method does not require complex operations in frequencydomain and achieves computational complexity reduction.

Groups of bats improve sonar efficiency through mutual suppression of pulse emissions.

Directory of Open Access Journals (Sweden)

Jenna eJarvis

2013-06-01

Full Text Available How bats adapt their sonar behavior to accommodate the noisiness of a crowded day roost is a mystery. Some bats change their pulse acoustics to enhance the distinction between theirs and another bat’s echoes, but additional mechanisms are needed to explain the bat sonar system’s exceptional resilience to jamming by conspecifics. Variable pulse repetition rate strategies offer one potential solution to this dynamic problem, but precisely how changes in pulse rate could improve sonar performance in social settings is unclear. Here we show that bats decrease their emission rates as population density increases, following a pattern that reflects a cumulative mutual suppression of each other’s pulse emissions. Playback of artificially-generated echolocation pulses similarly slowed emission rates, demonstrating that suppression was mediated by hearing the pulses of other bats. Slower emission rates did not support an antiphonal emission strategy but did reduce the relative proportion of emitted pulses that overlapped with another bat’s emissions, reducing the relative rate of mutual interference. The prevalence of acoustic interferences occurring amongst bats was empirically determined to be a linear function of population density and mean emission rates. Consequently as group size increased, small reductions in emission rates spread across the group partially mitigated the increase in interference rate. Drawing on lessons learned from communications networking theory we show how modest decreases in pulse emission rates can significantly increase the net information throughput of the shared acoustic space, thereby improving sonar efficiency for all individuals in a group. We propose that an automated acoustic suppression of pulse emissions triggered by bats hearing each other's emissions dynamically optimizes sonar efficiency for the entire group.

Automated detection of submerged navigational obstructions in freshwater impoundments with hull mounted sidescan sonar

Science.gov (United States)

Morris, Phillip A.

The prevalence of low-cost side scanning sonar systems mounted on small recreational vessels has created improved opportunities to identify and map submerged navigational hazards in freshwater impoundments. However, these economical sensors also present unique challenges for automated techniques. This research explores related literature in automated sonar imagery processing and mapping technology, proposes and implements a framework derived from these sources, and evaluates the approach with video collected from a recreational grade sonar system. Image analysis techniques including optical character recognition and an unsupervised computer automated detection (CAD) algorithm are employed to extract the transducer GPS coordinates and slant range distance of objects protruding from the lake bottom. The retrieved information is formatted for inclusion into a spatial mapping model. Specific attributes of the sonar sensors are modeled such that probability profiles may be projected onto a three dimensional gridded map. These profiles are computed from multiple points of view as sonar traces crisscross or come near each other. As lake levels fluctuate over time so do the elevation points of view. With each sonar record, the probability of a hazard existing at certain elevations at the respective grid points is updated with Bayesian mechanics. As reinforcing data is collected, the confidence of the map improves. Given a lake's current elevation and a vessel draft, a final generated map can identify areas of the lake that have a high probability of containing hazards that threaten navigation. The approach is implemented in C/C++ utilizing OpenCV, Tesseract OCR, and QGIS open source software and evaluated in a designated test area at Lake Lavon, Collin County, Texas.

Modulation, resolution and signal processing in radar, sonar and related systems

CERN Document Server

Benjamin, R; Costrell, L

1966-01-01

Electronics and Instrumentation, Volume 35: Modulation, Resolution and Signal Processing in Radar, Sonar and Related Systems presents the practical limitations and potentialities of advanced modulation systems. This book discusses the concepts and techniques in the radar context, but they are equally essential to sonar and to a wide range of signaling and data-processing applications, including seismology, radio astronomy, and band-spread communications.Organized into 15 chapters, this volume begins with an overview of the principal developments sought in pulse radar. This text then provides a

Sonar Headphone Selection for Optimum Performance: An Overview

National Research Council Canada - National Science Library

Russotti, Joseph

1995-01-01

.... The advantages and disadvantages of open and sealed circumaural headsets and recent developments in noise canceling headsets are discussed, along with the possibility of reducing noise levels in sonar spaces to permit use of higher fidelity headphone designs.

SONAR: A high-throughput pipeline for inferring antibody ontogenies from longitudinal sequencing of B cell transcripts

Directory of Open Access Journals (Sweden)

Chaim A Schramm

2016-09-01

Full Text Available The rapid advance of massively parallel or next-generation sequencing technologies has made possible the characterization of B cell receptor repertoires in ever greater detail, leading to a proliferation of software tools for processing and annotating this data. Of especial interest, however, is the capability to track the development of specific antibody lineages across time, which remains beyond the scope of most current programs. We have previously reported on the use of techniques such as inter- and intra-donor analysis and CDR3 tracing to identify transcripts related to an antibody of interest. Here, we present Software for the Ontogenic aNalysis of Antibody Repertoires (SONAR, capable of automating both general repertoire analysis and specialized techniques for investigating specific lineages. SONAR annotates next-generation sequencing data, identifies transcripts in a lineage of interest, and tracks lineage development across multiple time points. SONAR also generates figures, such as identity-divergence plots and longitudinal phylogenetic birthday trees, and provides interfaces to other programs such as DNAML and BEAST. SONAR can be downloaded as a ready-to-run Docker image or manually installed on a local machine. In the latter case, it can also be configured to take advantage of a high-performance computing cluster for the most computationally intensive steps, if available. In summary, this software provides a useful new tool for the processing of large next-generation sequencing datasets and the ontogenic analysis of neutralizing antibody lineages. SONAR can be found at https://github.com/scharch/SONAR and the Docker image can be obtained from https://hub.docker.com/r/scharch/sonar/.

The passive and active periods for the intermittent use of an active sensor to detect an evasive target

OpenAIRE

Bache, Niels

2013-01-01

Your task is to detect a submarine with your active sonar. The submarine can hear your active sonar before you can detect him. If the submarine is fast enough he can evade you before you can detect him. How do you then detect him? If you are using your active sonar continuously you will not detect him. Likewise, if you are not using your sonar at all. In between those two extremes there is an optimum. We will find that optimum. Or said more precisely and general: In the same two dimensional r...

Correlation Based Testing for Passive Sonar Picture Rationalization

National Research Council Canada - National Science Library

Mellema, Garfield R

2007-01-01

.... The sample correlation coefficient, is a statistical measure of relatedness. This paper describes the application of a test based on that measure to compare tracks produced by a probabilistic data association filter from a set of towed array sonar data. Keywords.

Behavioral Response of Reef Fish and Green Sea Turtles to Midfrequency Sonar.

Science.gov (United States)

Watwood, Stephanie L; Iafrate, Joseph D; Reyier, Eric A; Redfoot, William E

2016-01-01

There is growing concern over the potential effects of high-intensity sonar on wild fish populations and commercial fisheries. Acoustic telemetry was employed to measure the movements of free-ranging reef fish and sea turtles in Port Canaveral, FL, in response to routine submarine sonar testing. Twenty-five sheepshead (Archosargus probatocephalus), 28 gray snapper (Lutjanus griseus), and 29 green sea turtles (Chelonia mydas) were tagged, with movements monitored for a period of up to 4 months using an array of passive acoustic receivers. Baseline residency was examined for fish and sea turtles before, during, and after the test event. No mortality of tagged fish or sea turtles was evident from the sonar test event. There was a significant increase in the daily residency index for both sheepshead and gray snapper at the testing wharf subsequent to the event. No broad-scale movement from the study site was observed during or immediately after the test.

Sonar Image Enhancements for Improved Detection of Sea Mines

DEFF Research Database (Denmark)

Jespersen, Karl; Sørensen, Helge Bjarup Dissing; Zerr, Benoit

1999-01-01

In this paper, five methods for enhancing sonar images prior to automatic detection of sea mines are investigated. Two of the methods have previously been published in connection with detection systems and serve as reference. The three new enhancement approaches are variance stabilizing log...... transform, nonlinear filtering, and pixel averaging for speckle reduction. The effect of the enhancement step is tested by using the full prcessing chain i.e. enhancement, detection and thresholding to determine the number of detections and false alarms. Substituting different enhancement algorithms...... in the processing chain gives a precise measure of the performance of the enhancement stage. The test is performed using a sonar image database with images ranging from very simple to very complex. The result of the comparison indicates that the new enhancement approaches improve the detection performance....

Applying multibeam sonar and mathematical modeling for mapping seabed substrate and biota of offshore shallows

Science.gov (United States)

Herkül, Kristjan; Peterson, Anneliis; Paekivi, Sander

2017-06-01

Both basic science and marine spatial planning are in a need of high resolution spatially continuous data on seabed habitats and biota. As conventional point-wise sampling is unable to cover large spatial extents in high detail, it must be supplemented with remote sensing and modeling in order to fulfill the scientific and management needs. The combined use of in situ sampling, sonar scanning, and mathematical modeling is becoming the main method for mapping both abiotic and biotic seabed features. Further development and testing of the methods in varying locations and environmental settings is essential for moving towards unified and generally accepted methodology. To fill the relevant research gap in the Baltic Sea, we used multibeam sonar and mathematical modeling methods - generalized additive models (GAM) and random forest (RF) - together with underwater video to map seabed substrate and epibenthos of offshore shallows. In addition to testing the general applicability of the proposed complex of techniques, the predictive power of different sonar-based variables and modeling algorithms were tested. Mean depth, followed by mean backscatter, were the most influential variables in most of the models. Generally, mean values of sonar-based variables had higher predictive power than their standard deviations. The predictive accuracy of RF was higher than that of GAM. To conclude, we found the method to be feasible and with predictive accuracy similar to previous studies of sonar-based mapping.

Archaeological use of Synthetic Aperture Sonar on deepwater wreck sites in Skagerrak

DEFF Research Database (Denmark)

Maarleveld, Thijs J.; Ødegård, Øyvind; Hansen, Roy E.

2018-01-01

Marine archaeological surveying in deep waters has so far been challenging, mainly due to operational and technological constraints. The standard tool has been Side Scan Sonar (SSS) towed behind a surface vessel. Synthetic Aperture Sonar (SAS) technology is not subject to the traditional range....../resolution tradeoff, and produces results of considerably higher quality than traditional SSS. In 2015 and 2016 a comprehensive mapping of wrecks in Skagerrak, a large deepwater area off the south coast of Norway was undertaken, using an interferometric SAS system deployed on an autonomous underwater vehicle...

Contact-Level Multistatic Sonar Data Simulator for Tracker Performance Assessment

National Research Council Canada - National Science Library

Grimmett, Doug; Coraluppi, Stefano

2006-01-01

...). A brief description of the simulation approach is given, which includes simple sonar equation modeling, resulting in sensor-to-sensor target fading effects, as well as contact localization modeling...

Enhanced echolocation via robust statistics and super-resolution of sonar images

Science.gov (United States)

Kim, Kio

Echolocation is a process in which an animal uses acoustic signals to exchange information with environments. In a recent study, Neretti et al. have shown that the use of robust statistics can significantly improve the resiliency of echolocation against noise and enhance its accuracy by suppressing the development of sidelobes in the processing of an echo signal. In this research, the use of robust statistics is extended to problems in underwater explorations. The dissertation consists of two parts. Part I describes how robust statistics can enhance the identification of target objects, which in this case are cylindrical containers filled with four different liquids. Particularly, this work employs a variation of an existing robust estimator called an L-estimator, which was first suggested by Koenker and Bassett. As pointed out by Au et al.; a 'highlight interval' is an important feature, and it is closely related with many other important features that are known to be crucial for dolphin echolocation. A varied L-estimator described in this text is used to enhance the detection of highlight intervals, which eventually leads to a successful classification of echo signals. Part II extends the problem into 2 dimensions. Thanks to the advances in material and computer technology, various sonar imaging modalities are available on the market. By registering acoustic images from such video sequences, one can extract more information on the region of interest. Computer vision and image processing allowed application of robust statistics to the acoustic images produced by forward looking sonar systems, such as Dual-frequency Identification Sonar and ProViewer. The first use of robust statistics for sonar image enhancement in this text is in image registration. Random Sampling Consensus (RANSAC) is widely used for image registration. The registration algorithm using RANSAC is optimized for sonar image registration, and the performance is studied. The second use of robust

Studies on a Spatialized Audio Interface for Sonar

Science.gov (United States)

2011-10-03

addition of spatialized audio to visual displays for sonar is much akin to the development of talking movies in the early days of cinema and can be...than using the brute-force approach. PCA is one among several techniques that share similarities with the computational architecture of a

Inversion of Side Scan Sonar Motion and Posture in Seabed Geomorphology

Directory of Open Access Journals (Sweden)

Tao Weiliang

2017-08-01

Full Text Available Side scan sonar measurement platform, affected by underwater environment and its own motion precision, inevitably has posture and motion disturbance, which greatly affects accuracy of geomorphic image formation. It is difficult to sensitively and accurately capture these underwater disturbances by relying on auxiliary navigation devices. In this paper, we propose a method to invert motion and posture information of the measurement platform by using the matching relation between the strip images. The inversion algorithm is the key link in the image mosaic frame of side scan sonar, and the acquired motion posture information can effectively improve seabed topography and plotting accuracy and stability. In this paper, we first analyze influence of platform motion and posture on side scan sonar mapping, and establish the correlation model between motion, posture information and strip image matching information. Then, based on the model, a reverse neural network is established. Based on input, output of neural network, design of and test data set, a motion posture inversion mechanism based on strip image matching information is established. Accuracy and validity of the algorithm are verified by the experimental results.

Boundary layer structure observed by Shipborne Doppler Sonar in the Suez Canal zone

Energy Technology Data Exchange (ETDEWEB)

Fiocco, G. (Rome Univ. (Italy). Ist. di Fisica); Mastrantonio, G.; Ricotta, A. (Consiglio Nazionale delle Ricerche, Frascati (Italy). Lab. per il Plasma nello Spazio)

Observations of the boundary layer with a monostatic Sonar and other instrumentation were carried out in the Suez canal zone in January and March 1979, from the Italian m.v. Salernum on its way to and from a GARP assignment. The Sonar was operated almost continuously throughout the passages. In addition to the intensity records, an off-line Doppler analysis involving the use of the fast Fourier transform of the digitized Sonar echoes has provided the vertical component w of the velocity. In general, because of efficient filtering and of the good quality of the data, a vertical profile of w has been determined for each transmitted pulse. During a prolonged stay in the Bitter lakes vertical profiles of temperature and humidity were also obtained by deploying a tethered balloon. Large temporal and spatial temperature contrasts exist in the canal zone due to the presence of the desert and of large and small bodies of water. The ensuring phenomenology during the time of observation was quite varied.

AWARE Sonar and Sperm Whale Tagging (DE9906, EK500)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The AWARE sonar and sperm whale tagging cruise primarily focuses on whales in the continental shelf areas, with the following objectives: 1) Develop a better...

AWARE Sonar and Sperm Whale Tagging (DE0007, EK500)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The AWARE sonar and sperm whale tagging cruise primarily focuses on whales in the continental shelf areas, with the following objectives: 1) Develop a better...

Side-Scan_Sonar backscatter tiles for Hudson River, NY (.xtf)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Raw XTF files. Sonar data were collected November 6 to December 15, 2009, in the estuary north from Saugerties to Troy. Data Collection and Processing: The...

Assessing Sonar Performance in Realistic Environments

Science.gov (United States)

2012-10-01

Her Majesty the Queen in Right of Canada (Department of National Defence), 2012 c© Sa Majesté la Reine en droit du Canada (Ministère de la Défense... Victoria Class submarine. Q316 included a number of objectives specific to the ASPIRE project. These included demonstrating the use of gliders for the... Victoria Class C3 Optimization’ for the high level architecture for synthetic environment simulations • 20EA05: ‘Support to CMS: Ruggedized Sonar Test

Cetacean Social Behavioral Response to Sonar Exposure

Science.gov (United States)

2015-09-30

likely a social response which anticipates against potential loss of social cohesion, which may be induced by masking of their communication signals...Discrimination of fast click series produced by Risso’s dolphins for echolocation or communication . Wensveen P. et al (in review). The effectiveness of ramp...up of naval sonar to reduce sound levels received by marine mammals : experimental tests with humpback whales. Kvadsheim et al. (2015). The 3S2

Submarine Upward Looking Sonar Ice Draft Profile Data and Statistics

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — This data set consists of upward looking sonar draft data collected by submarines in the Arctic Ocean. It includes data from both U.S. Navy and Royal Navy...

The fusion of large scale classified side-scan sonar image mosaics.

Science.gov (United States)

Reed, Scott; Tena, Ruiz Ioseba; Capus, Chris; Petillot, Yvan

2006-07-01

This paper presents a unified framework for the creation of classified maps of the seafloor from sonar imagery. Significant challenges in photometric correction, classification, navigation and registration, and image fusion are addressed. The techniques described are directly applicable to a range of remote sensing problems. Recent advances in side-scan data correction are incorporated to compensate for the sonar beam pattern and motion of the acquisition platform. The corrected images are segmented using pixel-based textural features and standard classifiers. In parallel, the navigation of the sonar device is processed using Kalman filtering techniques. A simultaneous localization and mapping framework is adopted to improve the navigation accuracy and produce georeferenced mosaics of the segmented side-scan data. These are fused within a Markovian framework and two fusion models are presented. The first uses a voting scheme regularized by an isotropic Markov random field and is applicable when the reliability of each information source is unknown. The Markov model is also used to inpaint regions where no final classification decision can be reached using pixel level fusion. The second model formally introduces the reliability of each information source into a probabilistic model. Evaluation of the two models using both synthetic images and real data from a large scale survey shows significant quantitative and qualitative improvement using the fusion approach.

Robot path Planning Using  SIFT and Sonar Sensor Fusion

DEFF Research Database (Denmark)

Plascencia, Alfredo; Raposo, Hector

2007-01-01

and evidential grid maps, respectively. The approach is illustrated using actual measurements from a laboratory robot. The sensory information is obtained from a sonar array and the Scale Invariant Feature Transform (SIFT) algorithm. Finally, the resulting two evidential maps based on Bayes and Dempster theories...

Sonar: a multibase and parametric interface software for SDI

International Nuclear Information System (INIS)

Fonseca Passos, M.C.J. da

1986-01-01

Sonar - an automated service for selective dissemination of information (SDI) - developed by the Centro de Informacoes Nucleares (CIN) of the Comissao Nacional de Energia Nuclear (CNEN) is described. Emphasis is given to the multibase feature of the system based on the parametric interface between the system and an external data base reading subroutine. (Author) [pt

Bayesian reconstruction of seafloor shape from side-scan sonar measurements using a Markov Random Field

OpenAIRE

Woock, P.; Pak, Alexey

2014-01-01

To explore the seafloor, a side-scan sonar emits a directed acoustic signal and then records the returning (reflected) signal intensity as a function of time. The inversion of that process is not unique: multiple shapes may lead to identical measured responses. In this work, we suggest a Bayesian approach to reconstructing the 3D shape of the seafloor from multiple sonar measurements, inspired by the state-of-the-art methods of inverse raytracing that originated in computer vision. The space ...

Recreational-Grade Sidescan Sonar: Transforming a Low-Cost Leisure Gadget into a High Resolution Riverbed Remote Sensing Tool

Science.gov (United States)

Hamill, D. D.; Buscombe, D.; Wheaton, J. M.; Wilcock, P. R.

2016-12-01

The size and spatial organization of bed material, bed texture, is a fundamental physical attribute of lotic ecosystems. Traditional methods to map bed texture (such as physical samples and underwater video) are limited by low spatial coverage, and poor precision in positioning. Recreational grade sidescan sonar systems now offer the possibility of imaging submerged riverbed sediments at coverages and resolutions sufficient to identify subtle changes in bed texture, in any navigable body of water, with minimal cost, expertise in sonar, or logistical effort, thereby facilitating the democratization of acoustic imaging of benthic environments, to support ecohydrological studies in shallow water, not subject to the rigors of hydrographic standards, nor the preserve of hydroacoustic expertise and proprietary hydrographic industry software. We investigate the possibility of using recreational grade sidescan sonar for sedimentary change detection using a case study of repeat sidescan imaging of mixed sand-gravel-rock riverbeds in a debris-fan dominated canyon river, at a coverage and resolution that meets the objectives of studies of the effects of changing bed substrates on salmonid spawning. A repeat substrate mapping analysis on data collected between 2012 and 2015 on the Colorado River in Glen, Marble, and Grand Canyons will be presented. A detailed method has been developed to interpret and analyze non-survey-grade sidescan sonar data, encoded within an open source software tool developed by the authors. An automated technique to quantify bed texture directly from sidescan sonar imagery is tested against bed sediment observations from underwater video and multibeam sonar. Predictive relationships between known bed sediment observations and bed texture metrics could provide an objective means to quantify bed textures and to relate changes in bed texture to biological components of an aquatic ecosystem, at high temporal frequency, and with minimal logistical effort

'Merge' - A Filter for the Fusion of Dual-Frequency Sidescan Sonar Data

National Research Council Canada - National Science Library

Neill, Roger

1997-01-01

A filtering and data fusion technique is described which uses the correlation between the two data streams of a dual-frequency sidescan sonar in order to discriminate against noise and preferentially...

Automatic Detection of Sand Ripple Features in Sidescan Sonar Imagery

Science.gov (United States)

2014-07-09

Among the features used in forensic scientific fingerprint analysis are terminations or bifurcations of print ridges. Sidescan sonar imagery of ripple...always be pathological cases. The size of the blocks of pixels used in determining the ripple wavelength is evident in the output images on the right in

Monitoring the US ATLAS Network Infrastructure with perfSONAR-PS

International Nuclear Information System (INIS)

McKee, Shawn; Lake, Andrew; Laurens, Philippe; Severini, Horst; Wlodek, Tomasz; Wolff, Stephen; Zurawski, Jason

2012-01-01

Global scientific collaborations, such as ATLAS, continue to push the network requirements envelope. Data movement in this collaboration is routinely including the regular exchange of petabytes of datasets between the collection and analysis facilities in the coming years. These requirements place a high emphasis on networks functioning at peak efficiency and availability; the lack thereof could mean critical delays in the overall scientific progress of distributed data-intensive experiments like ATLAS. Network operations staff routinely must deal with problems deep in the infrastructure; this may be as benign as replacing a failing piece of equipment, or as complex as dealing with a multi-domain path that is experiencing data loss. In either case, it is crucial that effective monitoring and performance analysis tools are available to ease the burden of management. We will report on our experiences deploying and using the perfSONAR-PS Performance Toolkit at ATLAS sites in the United States. This software creates a dedicated monitoring server, capable of collecting and performing a wide range of passive and active network measurements. Each independent instance is managed locally, but able to federate on a global scale; enabling a full view of the network infrastructure that spans domain boundaries. This information, available through web service interfaces, can easily be retrieved to create customized applications. The US ATLAS collaboration has developed a centralized “dashboard” offering network administrators, users, and decision makers the ability to see the performance of the network at a glance. The dashboard framework includes the ability to notify users (alarm) when problems are found, thus allowing rapid response to potential problems and making perfSONAR-PS crucial to the operation of our distributed computing infrastructure.

Seafloor Characterisation of the Gakkel Ridge using Multibeam Sonar, Backscatter and Sidescan Data

Science.gov (United States)

Hatzky, J.; Schenke, H. W.

2003-04-01

The Gakkel Ridge in the Arctic Ocean was the object of the Arctic Mid-Ocean Ridge Expedition (AMORE) which was carried out by the research icebreakers R/V "Polarstern" (Germany) and USCGC "Healy" (USA) in the boreal summer 2001. This largely unexplored mid-ocean ridge (MOR) is of particular scientific interest due to its volcanic activity and tectonic structure. With spreading rates of 13mm/a in the western and 6 mm/a in the eastern part Gakkel Ridge is the slowest spreading MOR on earth (Michael et al., 2001). The surveyed area which is situated between 82°N / 8°W and 87°N / 75°E has a length of 8890 km and a varying width from 18 to 46 km. The range of measured depths reaches from 566 m on the top of a huge seamount to 5673 m in the central rift valley. Prominent underwater features of remarkable morphologic diversity (e.g. small volcanoes embedded in massive ridge flanks) were discovered in this region. One of the most important goals of the expedition was the compilation of a high resolution grid which serves as basis for a three dimensional digital terrain model (DTM), the derivation of contour lines and the production of bathymetric maps. Accordingly, two hull-mounted multibeam sonars were used for the depth data acquisition: the "Hydrosweep DS-2" system onboard "Polarstern" and the "Seabeam 2112" system onboard "Healy". In order to calculate a combined grid out of two independent data sets different technical specifications of both sonar systems (e.g. frequency, opening angle, number of beams, accuracy) had to be taken into account. Dense sea ice cover made the sonar measurements difficult. Thick floes caused hydroacoustic disturbances that heavily debased the data quality. Outliers and blunders of depths and navigation data had to be corrected in a drawn-out post-processing by appropriate software tools. Both echo sounding systems recorded backscatter information and sidescan data during the entire cruise. Onboard "Polarstern" the sub-bottom profiling

Multibeam sonar (DIDSON) assessment of American shad (Alosa sapidissima) approaching a hydroelectric dam

Science.gov (United States)

Grote, Ann B.; Bailey, Michael M.; Zydlewski, Joseph D.; Hightower, Joseph E.

2014-01-01

We investigated the fish community approaching the Veazie Dam on the Penobscot River, Maine, prior to implementation of a major dam removal and river restoration project. Multibeam sonar (dual-frequency identification sonar, DIDSON) surveys were conducted continuously at the fishway entrance from May to July in 2011. A 5% subsample of DIDSON data contained 43 793 fish targets, the majority of which were of Excellent (15.7%) or Good (73.01%) observation quality. Excellent quality DIDSON targets (n = 6876) were apportioned by species using a Bayesian mixture model based on four known fork length distributions (river herring (alewife,Alosa psuedoharengus, and blueback herring, Alosa aestivalis), American shad, Alosa sapidissima) and two size classes (one sea-winter and multi-sea-winter) of Atlantic salmon (Salmo salar). 76.2% of targets were assigned to the American shad distribution; Atlantic salmon accounted for 15.64%, and river herring 8.16% of observed targets. Shad-sized (99.0%) and salmon-sized (99.3%) targets approached the fishway almost exclusively during the day, whereas river herring-sized targets were observed both during the day (51.1%) and at night (48.9%). This approach demonstrates how multibeam sonar imaging can be used to evaluate community composition and species-specific movement patterns in systems where there is little overlap in the length distributions of target species.

Sonar atlas of caverns comprising the U.S. Strategic Petroleum Reserve. Volume 2, Big Hill Site, Texas.

Energy Technology Data Exchange (ETDEWEB)

Rautman, Christopher Arthur; Lord, Anna Snider

2007-08-01

Downhole sonar surveys from the four active U.S. Strategic Petroleum Reserve sites have been modeled and used to generate a four-volume sonar atlas, showing the three-dimensional geometry of each cavern. This volume 2 focuses on the Big Hill SPR site, located in southeastern Texas. Volumes 1, 3, and 4, respectively, present images for the Bayou Choctaw SPR site, Louisiana, the Bryan Mound SPR site, Texas, and the West Hackberry SPR site, Louisiana. The atlas uses a consistent presentation format throughout. The basic geometric measurements provided by the down-cavern surveys have also been used to generate a number of geometric attributes, the values of which have been mapped onto the geometric form of each cavern using a color-shading scheme. The intent of the various geometrical attributes is to highlight deviations of the cavern shape from the idealized cylindrical form of a carefully leached underground storage cavern in salt. The atlas format does not allow interpretation of such geometric deviations and anomalies. However, significant geometric anomalies, not directly related to the leaching history of the cavern, may provide insight into the internal structure of the relevant salt dome.

Sonar atlas of caverns comprising the U.S. Strategic Petroleum Reserve. Volume 1, Bayou Choctaw site, Louisiana.

Energy Technology Data Exchange (ETDEWEB)

Rautman, Christopher Arthur; Lord, Anna Snider

2007-10-01

Downhole sonar surveys from the four active U.S. Strategic Petroleum Reserve sites have been modeled and used to generate a four-volume sonar atlas, showing the three-dimensional geometry of each cavern. This volume 1 focuses on the Bayou Choctaw SPR site, located in southern Louisiana. Volumes 2, 3, and 4, respectively, present images for the Big Hill SPR site, Texas, the Bryan Mound SPR site, Texas, and the West Hackberry SPR site, Louisiana. The atlas uses a consistent presentation format throughout. The basic geometric measurements provided by the down-cavern surveys have also been used to generate a number of geometric attributes, the values of which have been mapped onto the geometric form of each cavern using a color-shading scheme. The intent of the various geometrical attributes is to highlight deviations of the cavern shape from the idealized cylindrical form of a carefully leached underground storage cavern in salt. The atlas format does not allow interpretation of such geometric deviations and anomalies. However, significant geometric anomalies, not directly related to the leaching history of the cavern, may provide insight into the internal structure of the relevant salt dome.

Sonar atlas of caverns comprising the U.S. Strategic Petroleum Reserve. Volume 3, Bryan Mound Site, Texas.

Energy Technology Data Exchange (ETDEWEB)

Rautman, Christopher Arthur; Lord, Anna Snider

2007-09-01

Downhole sonar surveys from the four active U.S. Strategic Petroleum Reserve sites have been modeled and used to generate a four-volume sonar atlas, showing the three-dimensional geometry of each cavern. This volume 3 focuses on the Bryan Mound SPR site, located in southeastern Texas. Volumes 1, 2, and 4, respectively, present images for the Bayou Choctaw SPR site, Louisiana, the Big Hill SPR site, Texas, and the West Hackberry SPR site, Louisiana. The atlas uses a consistent presentation format throughout. The basic geometric measurements provided by the down-cavern surveys have also been used to generate a number of geometric attributes, the values of which have been mapped onto the geometric form of each cavern using a color-shading scheme. The intent of the various geometrical attributes is to highlight deviations of the cavern shape from the idealized cylindrical form of a carefully leached underground storage cavern in salt. The atlas format does not allow interpretation of such geometric deviations and anomalies. However, significant geometric anomalies, not directly related to the leaching history of the cavern, may provide insight into the internal structure of the relevant salt dome.

Sonar atlas of caverns comprising the U.S. Strategic Petroleum Reserve. Volume 4, West Hackberry site, Louisiana.

Energy Technology Data Exchange (ETDEWEB)

Rautman, Christopher Arthur; Lord, Anna Snider

2007-09-01

Downhole sonar surveys from the four active U.S. Strategic Petroleum Reserve sites have been modeled and used to generate a four-volume sonar atlas, showing the three-dimensional geometry of each cavern. This volume 4 focuses on the West Hackberry SPR site, located in southwestern Louisiana. Volumes 1, 2, and 3, respectively, present images for the Bayou Choctaw SPR site, Louisiana, the Big Hill SPR site, Texas, and the Bryan Mound SPR site, Texas. The atlas uses a consistent presentation format throughout. The basic geometric measurements provided by the down-cavern surveys have also been used to generate a number of geometric attributes, the values of which have been mapped onto the geometric form of each cavern using a color-shading scheme. The intent of the various geometrical attributes is to highlight deviations of the cavern shape from the idealized cylindrical form of a carefully leached underground storage cavern in salt. The atlas format does not allow interpretation of such geometric deviations and anomalies. However, significant geometric anomalies, not directly related to the leaching history of the cavern, may provide insight into the internal structure of the relevant salt dome.

U.S. and Australian Mine Warfare Sonar Performance Assessment Using SWAT and Hodgson Models

National Research Council Canada - National Science Library

Dubsky, Barbra

2000-01-01

The purpose of this thesis was to investigate a shallow coastal region to compile a detailed environmental picture of its sediment composition and water characteristics and from this model MCM sonar...

Neural network modeling of a dolphin's sonar discrimination capabilities

OpenAIRE

Andersen, Lars Nonboe; René Rasmussen, A; Au, WWL; Nachtigall, PE; Roitblat, H.

1994-01-01

The capability of an echo-locating dolphin to discriminate differences in the wall thickness of cylinders was previously modeled by a counterpropagation neural network using only spectral information of the echoes [W. W. L. Au, J. Acoust. Soc. Am. 95, 2728–2735 (1994)]. In this study, both time and frequency information were used to model the dolphin discrimination capabilities. Echoes from the same cylinders were digitized using a broadband simulated dolphin sonar signal with the transducer ...

Application of passive sonar technology to mineral processing and oil sands applications : if you can measure it, you can manage it

Energy Technology Data Exchange (ETDEWEB)

O' Keefe, C.; Viega, J.; Fernald, M. [CiDRA Corp., Wallingford, CT (United States)

2007-07-01

SONAR-based flow and entrained air measurement instruments were described. This new class of industrial flow and compositional analyzers was developed by CiDRA to provide new measurement insight and quantifiable value to industrial process operators. Passive sonar array-based processing units have been installed worldwide in several industrial applications and are particularly suited for a wide range of mineral processing applications, including slurry flow rate measurement and fluid characterization. This paper also described the SONAR-based, clamp-on SONARtrac technology, a scalable platform that provides several other value added measurements and information such as speed of sound, entrained air/gas, gas hold-up, and velocity profile. Oil sands, tailings and bitumen slurries present considerable measurement challenges for in-line flow measurement devices in terms of measurement accuracy, reliability and maintenance. The sonar-based technology platform has been used in a variety of oil sands processes, hydrotransport, and minerals beneficiation applications. This paper described these applications with particular reference to difficult slurry flow measurement and control in the areas of comminution and flotation such as mill discharge, hydrocyclone feed/overflow, final concentrate, thickener discharge, and tailings. 5 refs., 4 tabs., 23 figs.

High-Resolution Multibeam Sonar Survey and Interactive 3-D Exploration of the D-Day Wrecks off Normandy

Science.gov (United States)

Mayer, L. A.; Calder, B.; Schmidt, J. S.

2003-12-01

Historically, archaeological investigations use sidescan sonar and marine magnetometers as initial search tools. Targets are then examined through direct observation by divers, video, or photographs. Magnetometers can demonstrate the presence, absence, and relative susceptibility of ferrous objects but provide little indication of the nature of the target. Sidescan sonar can present a clear image of the overall nature of a target and its surrounding environment, but the sidescan image is often distorted and contains little information about the true 3-D shape of the object. Optical techniques allow precise identification of objects but suffer from very limited range, even in the best of situations. Modern high-resolution multibeam sonar offers an opportunity to cover a relatively large area from a safe distance above the target, while resolving the true three-dimensional (3-D) shape of the object with centimeter-level resolution. The combination of 3-D mapping and interactive 3-D visualization techniques provides a powerful new means to explore underwater artifacts. A clear demonstration of the applicability of high-resolution multibeam sonar to wreck and artifact investigations occurred when the Naval Historical Center (NHC), the Center for Coastal and Ocean Mapping (CCOM) at the University of New Hampshire, and Reson Inc., collaborated to explore the state of preservation and impact on the surrounding environment of a series of wrecks located off the coast of Normandy, France, adjacent to the American landing sectors The survey augmented previously collected magnetometer and high-resolution sidescan sonar data using a Reson 8125 high-resolution focused multibeam sonar with 240, 0.5° (at nadir) beams distributed over a 120° swath. The team investigated 21 areas in water depths ranging from about three -to 30 meters (m); some areas contained individual targets such as landing craft, barges, a destroyer, troop carrier, etc., while others contained multiple smaller

The Blackboard Model of Computer Programming Applied to the Interpretation of Passive Sonar Data

National Research Council Canada - National Science Library

Liebing, David

1997-01-01

... (location, course, speed, classification, etc.). At present the potential volume of data produced by modern sonar systems is so large that unless some form of computer assistance is provided with the interpretation of this data, information...

High frequency sonar variability in littoral environments: Irregular particles and bubbles

Science.gov (United States)

Richards, Simon D.; Leighton, Timothy G.; White, Paul R.

2002-11-01

Littoral environments may be characterized by high concentrations of suspended particles. Such suspensions contribute to attenuation through visco-inertial absorption and scattering and may therefore be partially responsible for the observed variability in high frequency sonar performance in littoral environments. Microbubbles which are prevalent in littoral waters also contribute to volume attenuation through radiation, viscous and thermal damping and cause dispersion. The attenuation due to a polydisperse suspension of particles with depth-dependent concentration has been included in a sonar model. The effects of a depth-dependent, polydisperse population of microbubbles on attenuation, sound speed and volume reverberation are also included. Marine suspensions are characterized by nonspherical particles, often plate-like clay particles. Measurements of absorption in dilute suspensions of nonspherical particles have shown disagreement with predictions of spherical particle models. These measurements have been reanalyzed using three techniques for particle sizing: laser diffraction, gravitational sedimentation, and centrifugal sedimentation, highlighting the difficulty of characterizing polydisperse suspensions of irregular particles. The measurements have been compared with predictions of a model for suspensions of oblate spheroids. Excellent agreement is obtained between this model and the measurements for kaolin particles, without requiring any a priori knowledge of the measurements.

Recommendations for improved and coherent acquisition and processing of backscatter data from seafloor-mapping sonars

Science.gov (United States)

Lamarche, Geoffroy; Lurton, Xavier

2018-06-01

Multibeam echosounders are becoming widespread for the purposes of seafloor bathymetry mapping, but the acquisition and the use of seafloor backscatter measurements, acquired simultaneously with the bathymetric data, are still insufficiently understood, controlled and standardized. This presents an obstacle to well-accepted, standardized analysis and application by end users. The Marine Geological and Biological Habitat Mapping group (Geohab.org) has long recognized the need for better coherence and common agreement on acquisition, processing and interpretation of seafloor backscatter data, and established the Backscatter Working Group (BSWG) in May 2013. This paper presents an overview of this initiative, the mandate, structure and program of the working group, and a synopsis of the BSWG Guidelines and Recommendations to date. The paper includes (1) an overview of the current status in sensors and techniques available in seafloor backscatter data from multibeam sonars; (2) the presentation of the BSWG structure and results; (3) recommendations to operators, end-users, sonar manufacturers, and software developers using sonar backscatter for seafloor-mapping applications, for best practice methods and approaches for data acquisition and processing; and (4) a discussion on the development needs for future systems and data processing. We propose for the first time a nomenclature of backscatter processing levels that affords a means to accurately and efficiently describe the data processing status, and to facilitate comparisons of final products from various origins.

Slope angle studies from multibeam sonar data on three seamounts in Central Indian Basin

Digital Repository Service at National Institute of Oceanography (India)

Kodagali, V.N.

Slope angles are powerful morphometric tools. Slope angle studies in manganese nodule areas using the Multi Beam Sonar (MBS) data is useful to the mining geologist. A technique to convert depth grid generated from MBS data to slope angle values data...

Cost-Effective Mapping of Benthic Habitats in Inland Reservoirs through Split-Beam Sonar, Indicator Kriging, and Historical Geologic Data

Energy Technology Data Exchange (ETDEWEB)

Venteris, Erik R.; May, Cassandra

2014-04-23

Because bottom substrate composition is an important control on the temporal and spatial location of the aquatic community, accurate maps of benthic habitats of inland lakes and reservoirs provide valuable information to managers, recreational users, and scientists. Therefore, we collected vertical, split-beam sonar data (roughness [E1], hardness [E2], and bathymetry) and sediment samples to make such maps. Statistical calibration between sonar parameters and sediment classes was problematic because the E1:E2 ratios for soft (muck and clay) sediments overlapped a lower and narrower range for hard (gravel) substrates. Thus, we used indicator kriging (IK) to map the probability that unsampled locations did not contain coarse sediments. To overcome the calibration issue we tested proxies for the natural processes and anthropogenic history of the reservoir as potential predictive variables. Of these, a geologic map proved to be the most useful. The central alluvial valley and mudflats contained mainly muck and organic-rich clays. The surrounding glacial till and shale bedrock uplands contained mainly poorly sorted gravels. Anomalies in the sonar data suggested that the organic-rich sediments also contained trapped gases, presenting additional interpretive issues for the mapping. We extended the capability of inexpensive split-beam sonar units through the incorporation of historic geologic maps and other records as well as validation with dredge samples. Through the integration of information from multiple data sets, were able to objectively identify bottom substrate and provide reservoir users with an accurate map of available benthic habitat.

Combining split-beam and dual-frequency identification sonars to estimate abundance of anadromous fishes in the Roanoke River, North Carolina

Science.gov (United States)

Hughes, Jacob B.; Hightower, Joseph E.

2015-01-01

Riverine hydroacoustic techniques are an effective method for evaluating abundance of upstream migrating anadromous fishes. To use these methods in the Roanoke River, North Carolina, at a wide site with uneven bottom topography, we used a combination of split-beam sonar and dual-frequency identification sonar (DIDSON) deployments. We aimed a split-beam sonar horizontally to monitor midchannel and near-bottom zones continuously over the 3-month spring monitoring periods in 2010 and 2011. The DIDSON was rotated between seven cross-channel locations (using a vertical aim) and nearshore regions (using horizontal aims). Vertical deployment addressed blind spots in split-beam coverage along the bottom and provided reliable information about the cross-channel and vertical distributions of upstream migrants. Using a Bayesian framework, we modeled sonar counts within four cross-channel strata and apportioned counts by species using species proportions from boat electrofishing and gill netting. Modeled estimates (95% credible intervals [CIs]) of total upstream migrants in 2010 and 2011 were 2.5 million (95% CI, 2.4–2.6 million) and 3.6 million (95% CI, 3.4–3.9 million), respectively. Results indicated that upstream migrants are extremely shore- and bottom-oriented, suggesting nearshore DIDSON monitoring improved the accuracy and precision of our estimates. This monitoring protocol and model may be widely applicable to river systems regardless of their cross-sectional width or profile.

IDENTIFIKASI PROFIL DASAR LAUT MENGGUNAKAN INSTRUMEN SIDE SCAN SONAR DENGAN METODE BEAM PATTERN DISCRETE-EQUI-SPACED UNSHADED LINE ARRAY

Directory of Open Access Journals (Sweden)

Muhammad Zainuddin Lubis

2017-05-01

Full Text Available Laut Punggur merupakan laut yang terletak di Batam, Kepulauan Riau yang mempunyai beragam habitat objek,dan bentuk struktur bawah laut yang memiliki dinamika laut yang sangat tinggi. Side scan sonar (SSS merupakan instrumen pengembangan sistem sonar yang mampu menunjukkan dalam gambar dua dimensional permukaan dasar laut dengan kondisi kontur, topografi, dan target secara bersamaan. Metode Beam Pattern Discrete-Equi-Spaced Unshaded Line Array digunakan untuk menghitung beam pattern dua dimensi yang tergantung pada sudut dari gelombang suara yang masuk dari sumbu array yang diterima tergantung pada sudut di mana sinar suara pada array. Penelitian ini dilakukan pada Desember 2016 di laut Punggur,Batam, Kepulauan Riau-Indonesia, dengan koordinat 104 ° 08,7102 E dan 1° 03,2448 N sampai 1 ° 03.3977 N dan 104 ° 08,8133 E, menggunakan instrumen Side Scan Sonar C-Max CM2 Tow fish dengan frekuensi 325 kHz. Hasil yang diperoleh dari perekaman terdapat 7 target, dan Beam pattern dari metode Beam Discrete-Equi-Spaced Unshaded Line Array target 4 memiliki nilai tertinggi pada directivity Pattern yaitu 21.08 dB. Hasil model beam pattern ini memiliki nilai pusat pada incidence angle (o terhadap Directivity pattern (dB tidak berada di nilai 0 ataupun pada pusat beam pattern yang dihasilkan pada target 6 dengan nilai incident angle -1.5 o dan 1.5o mengalami penurunan hingga -40 dB. Karakteristik sedimen dasar perairan di laut punggur ditemukan lebih banyak pasir. Hasil metode Beam Discrete-Equi-Spaced Unshaded Line Array ditemukan bangkai kapal tenggelam.Kata Kunci: Side Scan Sonar, Beam Pattern Discrete-Equi-Spaced Unshaded Line Array, Incidence angle, Directivity pattern IDENTIFICATION OF SEABED PROFILE USING SIDE SCAN SONAR INSTRUMENT WITH PATTERN DISCRETE-EQUI-SPACED UNSHADED LINE ARRAY METHODRiau Islands is an island that has a variety of habitat objects, and forms of submarine structures that have a very high ocean dynamics, Punggur Sea is the sea

Data fusion from multiple passive sonar nodes for target localisation and false alarm reduction

NARCIS (Netherlands)

Hunter, A.J.; Fillinger, L.; Zampolli, M.; Clarijs, M.C.

2012-01-01

A PHD particle filter implementation has been detailed for the fusion of measurements from multiple passive sonar nodes. It has been demonstrated on simulated metadata and on experimental passive acoustic data of divers and small boats collected in an operational port environment. Fusion at the

Sonar sound groups and increased terminal buzz duration reflect task complexity in hunting bats

DEFF Research Database (Denmark)

Hulgard, K.; Ratcliffe, J. M.

2016-01-01

to prey under presumably more difficult conditions. Specifically, we found Daubenton's bats, Myotis daubentonii, produced longer buzzes when aerial-hawking versus water-trawling prey, but that bats taking revolving air- and water-borne prey produced more sonar sound groups than did the bats when taking...

Cost-effective mapping of benthic habitats in inland reservoirs through split-beam sonar, indicator kriging, and historical geologic data.

Directory of Open Access Journals (Sweden)

Erik R Venteris

Full Text Available Because bottom substrate composition is an important control on the temporal and spatial location of the aquatic community, accurate maps of benthic habitats of inland lakes and reservoirs provide valuable information to managers, recreational users, and scientists. Therefore, we collected vertical, split-beam sonar data (roughness [E1], hardness [E2], and bathymetry and sediment samples to make such maps. Statistical calibration between sonar parameters and sediment classes was problematic because the E1:E2 ratios for soft (muck and clay sediments overlapped a lower and narrower range for hard (gravel substrates. Thus, we used indicator kriging (IK to map the probability that unsampled locations did not contain coarse sediments. To overcome the calibration issue we tested proxies for the natural processes and anthropogenic history of the reservoir as potential predictive variables. Of these, a geologic map proved to be the most useful. The central alluvial valley and mudflats contained mainly muck and organic-rich clays. The surrounding glacial till and shale bedrock uplands contained mainly poorly sorted gravels. Anomalies in the sonar data suggested that the organic-rich sediments also contained trapped gases, presenting additional interpretive issues for the mapping. We extended the capability of inexpensive split-beam sonar units through the incorporation of historic geologic maps and other records as well as validation with dredge samples. Through the integration of information from multiple data sets, were able to objectively identify bottom substrate and provide reservoir users with an accurate map of available benthic habitat.

Advanced signal processing theory and implementation for sonar, radar, and non-invasive medical diagnostic systems

CERN Document Server

Stergiopoulos, Stergios

2009-01-01

Integrates topics of signal processing from sonar, radar, and medical system technologies by identifying their concept similarities. This book covers non-invasive medical diagnostic system applications, including intracranial ultrasound, a technology that attempts to address non-invasive detection on brain injuries and stroke.

SIMONA: A multi-purpose acoustic data simulator for development and testing of sonar signal processing

NARCIS (Netherlands)

Robert, M.K.; Groen, J.; Konijnendijk, N.J.

2005-01-01

The development of undersea defence technologies such as sonar relies heavily on the availability of high quality acoustic data. However, data acquisition is particularly expensive as sea trials involve experienced manpower and costly high-tech equipment. Also, at sea, the environment remains

Final report of DOE project "Detection, Localization and Diagnosis of Performance Problems Using PerfSONAR"

Energy Technology Data Exchange (ETDEWEB)

Dovrolis, Konstantinos [Georgia Tech

2014-04-15

We present the development of a middleware service, called Pythia, that is able to detect, localize, and diagnose performance problems in the network paths that interconnect research sites that are of interest to DOE. The proposed service can analyze perfSONAR data collected from all participating sites.

Wall-corner classification using sonar: a new approach based on geometric features.

Science.gov (United States)

Martínez, Milagros; Benet, Ginés

2010-01-01

Ultrasonic signals coming from rotary sonar sensors in a robot gives us several features about the environment. This enables us to locate and classify the objects in the scenario of the robot. Each object and reflector produces a series of peaks in the amplitude of the signal. The radial and angular position of the sonar sensor gives information about location and their amplitudes offer information about the nature of the surface. Early works showed that the amplitude can be modeled and used to classify objects with very good results at short distances-80% average success in classifying both walls and corners at distances less than 1.5 m. In this paper, a new set of geometric features derived from the amplitude analysis of the echo is presented. These features constitute a set of characteristics that can be used to improve the results of classification at distances from 1.5 m to 4 m. Also, a comparative study on classification algorithms widely used in pattern recognition techniques has been carried out for sensor distances ranging between 0.5 to 4 m, and with incidence angles ranging between 20° to 70°. Experimental results show an enhancement on the success in classification rates when these geometric features are considered.

Archive of side scan sonar and swath bathymetry data collected during USGS cruise 10CCT01 offshore of Cat Island, Gulf Islands National Seashore, Mississippi, March 2010

Science.gov (United States)

DeWitt, Nancy T.; Flocks, James G.; Pfeiffer, William R.; Wiese, Dana S.

2010-01-01

In March of 2010, the U.S. Geological Survey (USGS) conducted geophysical surveys east of Cat Island, Mississippi (fig. 1). The efforts were part of the USGS Gulf of Mexico Science Coordination partnership with the U.S. Army Corps of Engineers (USACE) to assist the Mississippi Coastal Improvements Program (MsCIP) and the Northern Gulf of Mexico (NGOM) Ecosystem Change and Hazards Susceptibility Project by mapping the shallow geological stratigraphic framework of the Mississippi Barrier Island Complex. These geophysical surveys will provide the data necessary for scientists to define, interpret, and provide baseline bathymetry and seafloor habitat for this area and to aid scientists in predicting future geomorpholocial changes of the islands with respect to climate change, storm impact, and sea-level rise. Furthermore, these data will provide information for barrier island restoration, particularly in Camille Cut, and provide protection for the historical Fort Massachusetts. For more information refer to http://ngom.usgs.gov/gomsc/mscip/index.html. This report serves as an archive of the processed swath bathymetry and side scan sonar data (SSS). Data products herein include gridded and interpolated surfaces, surface images, and x,y,z data products for both swath bathymetry and side scan sonar imagery. Additional files include trackline maps, navigation files, GIS files, Field Activity Collection System (FACS) logs, and formal FGDC metadata. Scanned images of the handwritten FACS logs and digital FACS logs are also provided as PDF files. Refer to the Acronyms page for expansion of acronyms and abbreviations used in this report or hold the cursor over an acronym for a pop-up explanation. The USGS St. Petersburg Coastal and Marine Science Center assigns a unique identifier to each cruise or field activity. For example, 10CCT01 tells us the data were collected in 2010 for the Coastal Change and Transport (CCT) study and the data were collected during the first field

3S2: Behavioral Response Studies of Cetaceans to Navy Sonar Signals in Norwegian Waters

Science.gov (United States)

2015-09-30

Sonar Signals in Norwegian Waters Peter L. Tyack University of St Andrews School of Biology Scottish Oceans Institute East Sands St Andrews...with a tagged minke whale. Data in the top 4 panels were derived from observations from the trackboat (‘ MOB ’). Note the strong change in diving

Characteristics of a sandy depositional lobe on the outer Mississippi fan from SeaMARC IA sidescan sonar images

Science.gov (United States)

Twichell, David C.; Schwab, William C.; Nelson, C. Hans; Kenyon, Neil H.; Lee, Homa J.

1992-01-01

SeaMARC IA sidescan sonar images of the distal reaches of a depositional lobe on the Mississippi Fan show that channelized rather than unconfined transport was the dominant transport mechanism for coarse-grained sediment during the formation of this part of the deep-sea fan. Overbank sheet flow of sands was not an important process in the transport and deposition of the sandy and silty sediment found on this fan. The dendritic distributary pattern and the high order of splaying of the channels, only one of which appears to have been active at a time, suggest that coarse-grained deposits on this fan are laterally discontinuous.

3D Imaging with a Sonar Sensor and an Automated 3-Axes Frame for Selective Spraying in Controlled Conditions

Directory of Open Access Journals (Sweden)

David Reiser

2017-02-01

Full Text Available Autonomous selective spraying could be a way for agriculture to reduce production costs, save resources, protect the environment and help to fulfill specific pesticide regulations. The objective of this paper was to investigate the use of a low-cost sonar sensor for autonomous selective spraying of single plants. For this, a belt driven autonomous robot was used with an attached 3-axes frame with three degrees of freedom. In the tool center point (TCP of the 3-axes frame, a sonar sensor and a spray valve were attached to create a point cloud representation of the surface, detect plants in the area and perform selective spraying. The autonomous robot was tested on replicates of artificial crop plants. The location of each plant was identified out of the acquired point cloud with the help of Euclidian clustering. The gained plant positions were spatially transformed from the coordinates of the sonar sensor to the valve location to determine the exact irrigation points. The results showed that the robot was able to automatically detect the position of each plant with an accuracy of 2.7 cm and could spray on these selected points. This selective spraying reduced the used liquid by 72%, when comparing it to a conventional spraying method in the same conditions.

Dose-response relationships for the onset of avoidance of sonar by free-ranging killer whales

NARCIS (Netherlands)

Miller, P.J.O.; Antunes, R.N.; Wensveen, P.J.; Samarra, F.I.P.; Alves, A.C.; Tyack, P.L.; Kvadsheim, P.H.; Kleivane, L.; Lam, F.P.A.; Ainslie, M.A.; Thomas, L.

2014-01-01

Eight experimentally controlled exposures to 1−2 kHz or 6−7 kHz sonar signals were conducted with four killer whale groups. The source level and proximity of the source were increased during each exposure in order to reveal response thresholds. Detailed inspection of movements during each exposure

Use of Multibeam and Dual-Beam Sonar Systems to Observe Cavitating Flow Produced by Ferryboats: In a Marine Renewable Energy Perspective

Directory of Open Access Journals (Sweden)

Francisco Francisco

2017-07-01

Full Text Available With the prospect to deploy hydrokinetic energy converters in areas with heavy boat traffic, a study was conducted to observe and assess the depth range of cavitating flow produced by ferryboats in narrow channels. This study was conducted in the vicinity of Finnhamn Island in Stockholm Archipelago. The objectives of the survey were to assess whether the sonar systems were able to observe and measure the depth of what can be cavitating flow (in a form of convected cloud cavitation produced by one specific type of ferryboats frequently operating in that route, as well as investigate if the cavitating flow within the wake would propagate deep enough to disturb the water column underneath the surface. A multibeam and a dual-beam sonar systems were used as measurement instruments. The hypothesis was that strong and deep wake can disturb the optimal operation of a hydrokinetic energy converter, therefore causing damages to its rotors and hydrofoils. The results showed that both sonar system could detect cavitating flows including its strength, part of the geometrical shape and propagation depth. Moreover, the boat with a propeller thruster produced cavitating flow with an intense core reaching 4 m of depth while lasting approximately 90 s. The ferry with waterjet thruster produced a less intense cavitating flow; the core reached depths of approximately 6 m, and lasted about 90 s. From this study, it was concluded that multibeam and dual-beam sonar systems with operating frequencies higher than 200 kHz were able to detect cavitating flows in real conditions, as long as they are properly deployed and the data properly analyzed.

Modeling Effectiveness of Gradual Increases in Source Level to Mitigate Effects of Sonar on Marine Mammals

NARCIS (Netherlands)

Benda-Beckmann, A.M. von; Wensveen, P.J.; Kvadsheim, P.H.; Lam, F.P.A.; Miller, P.J.O.; Tyack, P.L.; Ainslie, M.A.

2013-01-01

Ramp-up or soft-start procedures (i.e., gradual increase in the source level) are used to mitigate the effect of sonar sound on marine mammals, although no one to date has tested whether ramp-up procedures are effective at reducing the effect of sound on marine mammals. We investigated the

Olympic Coast National Marine Sanctuary - mos120_0602b - Side scan sonar mosaic from survey effort 120_0602

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — This side scan sonar imagery of the sea floor (70-90 m water depths) was mosaiced from acoustic data collected in 2006 aboard the R/V Tatoosh. A Klein System 3000...

Olympic Coast National Marine Sanctuary - mos120_0602a - Side scan sonar mosaic from survey effort 120_0602

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — This side scan sonar imagery of the sea floor (35-55 m water depths) was mosaiced from acoustic data collected in 2006 aboard the R/V Tatoosh. A Klein System 3000...

Olympic Coast National Marine Sanctuary - mos122_0702.tif - Side scan sonar mosaic from survey effort 122_0702.

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — This side scan sonar imagery of the sea floor (15-35 m water depths) was mosaiced from acoustic data collected in 2007 aboard the R/V Tatoosh. A Klein System 3000...

Analysis of a new unidimensional model and lateral vibrations of 1-3 piezocomposite side scan sonar array

CSIR Research Space (South Africa)

Shatalov, MY

2006-01-01

Full Text Available . Lamb modes of the 1-3 piezocomposites are investigated in term of the Certon-Patat membrane model by means of direct variational method application. A new design of a 1-3 piezocomposite side scan SONAR array is considered. An implementation of the array...

78 FR 73009 - Takes of Marine Mammals Incidental to Specified Activities; U.S. Navy Training and Testing...

Science.gov (United States)

2013-12-04

.... Synthetic Aperture Sonars SAS1 MF SAS systems. (SAS): Sonars in which SAS2 HF SAS systems. active acoustic... sails are not dedicated ASW events and involve multiple warfare areas. Non-Impulsive ASW for Composite... Grenades. anti-swimmer grenades to defend against hostile divers (e.g., Visit, Board, Search, and Seizure...

Severity of Expert-Identified Behavioural Responses of Humpback Whale, Minke Whale, and Northern Bottlenose Whale to Naval Sonar

NARCIS (Netherlands)

Sivle, L.D.; Kvadsheim, P.H.; Cure, C.; Isojunno, S.; Wensveen, P.J.; Lam, F.P.A.; Visser, F.; Kleivane, L.; Tyack, P.L.; Harris, C.M.; Miller, P.J.O.

2015-01-01

Controlled exposure experiments using 1 to2 kHz sonar signals were conducted with 11 humpback whales (Megaptera novaeangliae), one minke whale (Balaenoptera acutorostrata), and one northern bottlenose whale (Hyperoodon ampullatus) during three field trials from 2011 to 2013. Ship approaches without

Bubble Clouds and their Transport within the Surf Zone as Measured with a Distributed Array of Upward-Looking Sonars

National Research Council Canada - National Science Library

Dahl, Peter

2000-01-01

... in the surf zone and the effects of these bubbles on acoustic propagation. This paper discusses data gathered by the Applied Physics Laboratory, University of Washington, using a set of four upward-looking sonars (frequency 240 kHz...

Passive synthetic aperture sonar techniques in combination with tow ship noise canceling: application to a triplet towed array

NARCIS (Netherlands)

Colin, M.E.G.D.; Groen, J.

2002-01-01

An important issue in research on passive ASW operations is improvement in signal-to-noise ratio (SNR) and bearing resolution for targets emitting low frequency signals. One of the techniques believed to improve these characteristics is Synthetic Aperture Sonar (SAS). The method is based on the

Automatic Target Recognition in Synthetic Aperture Sonar Images Based on Geometrical Feature Extraction

Directory of Open Access Journals (Sweden)

J. Del Rio Vera

2009-01-01

Full Text Available This paper presents a new supervised classification approach for automated target recognition (ATR in SAS images. The recognition procedure starts with a novel segmentation stage based on the Hilbert transform. A number of geometrical features are then extracted and used to classify observed objects against a previously compiled database of target and non-target features. The proposed approach has been tested on a set of 1528 simulated images created by the NURC SIGMAS sonar model, achieving up to 95% classification accuracy.

Algorithms and data structures for automated change detection and classification of sidescan sonar imagery

Science.gov (United States)

Gendron, Marlin Lee

During Mine Warfare (MIW) operations, MIW analysts perform change detection by visually comparing historical sidescan sonar imagery (SSI) collected by a sidescan sonar with recently collected SSI in an attempt to identify objects (which might be explosive mines) placed at sea since the last time the area was surveyed. This dissertation presents a data structure and three algorithms, developed by the author, that are part of an automated change detection and classification (ACDC) system. MIW analysts at the Naval Oceanographic Office, to reduce the amount of time to perform change detection, are currently using ACDC. The dissertation introductory chapter gives background information on change detection, ACDC, and describes how SSI is produced from raw sonar data. Chapter 2 presents the author's Geospatial Bitmap (GB) data structure, which is capable of storing information geographically and is utilized by the three algorithms. This chapter shows that a GB data structure used in a polygon-smoothing algorithm ran between 1.3--48.4x faster than a sparse matrix data structure. Chapter 3 describes the GB clustering algorithm, which is the author's repeatable, order-independent method for clustering. Results from tests performed in this chapter show that the time to cluster a set of points is not affected by the distribution or the order of the points. In Chapter 4, the author presents his real-time computer-aided detection (CAD) algorithm that automatically detects mine-like objects on the seafloor in SSI. The author ran his GB-based CAD algorithm on real SSI data, and results of these tests indicate that his real-time CAD algorithm performs comparably to or better than other non-real-time CAD algorithms. The author presents his computer-aided search (CAS) algorithm in Chapter 5. CAS helps MIW analysts locate mine-like features that are geospatially close to previously detected features. A comparison between the CAS and a great circle distance algorithm shows that the

On Estimation Of The Orientation Of Mobile Robots Using Turning Functions And SONAR Information

Directory of Open Access Journals (Sweden)

Dorel AIORDACHIOAIE

2003-12-01

Full Text Available SONAR systems are widely used by some artificial objects, e.g. robots, and by animals, e.g. bats, for navigation and pattern recognition. The objective of this paper is to present a solution on the estimation of the orientation in the environment of mobile robots, in the context of navigation, using the turning function approach. The results are shown to be accurate and can be used further in the design of navigation strategies of mobile robots.

Discrimination of Cylinders with Different Wall Thicknesses using Neural Networks and Simulated Dolphin Sonar Signals

DEFF Research Database (Denmark)

Andersen, Lars Nonboe; Au, Whitlow; Larsen, Jan

1999-01-01

This paper describes a method integrating neural networks into a system for recognizing underwater objects. The system is based on a combination of simulated dolphin sonar signals, simulated auditory filters and artificial neural networks. The system is tested on a cylinder wall thickness...... difference experiment and demonstrates high accuracy for small wall thickness differences. Results from the experiment are compared with results obtained by a false killer whale (pseudorca crassidens)....

On the design and construction of drifting-mine test targets for sonar, radar and electro-optical detection experiments

NARCIS (Netherlands)

Dol, H.S.

2014-01-01

The timely detection of small hazardous objects at the sea surface, such as drifting mines, is challenging for ship-mounted sensor systems, both for underwater sensor systems like sonar and above-water sensor systems like radar and electro-optics (lidar, infrared/visual cameras). This is due to the

Underwater object classification using scattering transform of sonar signals

Science.gov (United States)

Saito, Naoki; Weber, David S.

2017-08-01

In this paper, we apply the scattering transform (ST)-a nonlinear map based off of a convolutional neural network (CNN)-to classification of underwater objects using sonar signals. The ST formalizes the observation that the filters learned by a CNN have wavelet-like structure. We achieve effective binary classification both on a real dataset of Unexploded Ordinance (UXOs), as well as synthetically generated examples. We also explore the effects on the waveforms with respect to changes in the object domain (e.g., translation, rotation, and acoustic impedance, etc.), and examine the consequences coming from theoretical results for the scattering transform. We show that the scattering transform is capable of excellent classification on both the synthetic and real problems, thanks to having more quasi-invariance properties that are well-suited to translation and rotation of the object.

An Adaptive Cultural Algorithm with Improved Quantum-behaved Particle Swarm Optimization for Sonar Image Detection.

Science.gov (United States)

Wang, Xingmei; Hao, Wenqian; Li, Qiming

2017-12-18

This paper proposes an adaptive cultural algorithm with improved quantum-behaved particle swarm optimization (ACA-IQPSO) to detect the underwater sonar image. In the population space, to improve searching ability of particles, iterative times and the fitness value of particles are regarded as factors to adaptively adjust the contraction-expansion coefficient of the quantum-behaved particle swarm optimization algorithm (QPSO). The improved quantum-behaved particle swarm optimization algorithm (IQPSO) can make particles adjust their behaviours according to their quality. In the belief space, a new update strategy is adopted to update cultural individuals according to the idea of the update strategy in shuffled frog leaping algorithm (SFLA). Moreover, to enhance the utilization of information in the population space and belief space, accept function and influence function are redesigned in the new communication protocol. The experimental results show that ACA-IQPSO can obtain good clustering centres according to the grey distribution information of underwater sonar images, and accurately complete underwater objects detection. Compared with other algorithms, the proposed ACA-IQPSO has good effectiveness, excellent adaptability, a powerful searching ability and high convergence efficiency. Meanwhile, the experimental results of the benchmark functions can further demonstrate that the proposed ACA-IQPSO has better searching ability, convergence efficiency and stability.

Burial and exhumation of temperate bedrock reefs as elucidated by repetitive high-resolution sea floor sonar surveys: Spatial patterns and impacts to species' richness and diversity

Science.gov (United States)

Storlazzi, Curt D.; Fregoso, Theresa A.; Figurski, Jared D.; Freiwald, Jan; Lonhart, Steve I.; Finlayson, David P.

2013-01-01

To understand how chronic sediment burial and scour contribute to variation in the structure of algal and invertebrate communities on temperate bedrock reefs, the dynamics of the substrate and communities were monitored at locations that experience sand inundation and adjacent areas that do not. Co-located benthic scuba-transect surveys and high-resolution swath-sonar surveys were completed on bedrock reefs on the inner shelf of northern Monterey Bay, CA, in early winter 2009, spring 2010, and summer 2010. Analysis of the sonar surveys demonstrates that during the 8 months over which the surveys were conducted, 19.6% of the study area was buried by sand while erosion resulted in the exposure of bedrock over 13.8% of the study area; the remainder underwent no change between the surveys. Substrate classifications from the benthic transect surveys correlated with classifications generated from the sonar surveys, demonstrating the capacity of high-resolution sonar surveys to detect burial of bedrock reefs by sediment. On bedrock habitat that underwent burial and exhumation, species' diversity and richness of rock-associated sessile and mobile organisms were 50–66% lower as compared to adjacent stable bedrock habitat. While intermediate levels of disturbance can increase the diversity and richness of communities, these findings demonstrate that burial and exhumation of bedrock habitat are sources of severe disturbance. We suggest that substrate dynamics must be considered when developing predictions of benthic community distributions based on sea floor imagery. These results highlight the need for predictive models of substrate dynamics and for a better understanding of how burial and exhumation shape benthic communities.

Acoustic Imaging of Selected Areas of Gdansk Bay with the Aid of Parametric Echosounder and Side-Scan Sonar

Directory of Open Access Journals (Sweden)

Grelowska Grażyna

2017-12-01

Full Text Available The article presents and analyses the data recorded during sounding of the Gdansk Bay seabed with the aid of a parametric echosounder and a side-scan sonar. The accuracy of seabed structure examination, as a condition for obtaining valuable results, requires correct configuration of echolocation devices and proper calibration of peripheral devices, such as the survey unit geographical position sensor - GPS, the navigation unit, the MRU-Z sensor of pitch, roll and heave, and the sound velocity meter, which deliver the data to the bathymetric measurement system. Parametric seabed profilers deliver two types of data: the envelope, and the detailed echo signal without processing. The envelope is used for data visualisation in the form of online echograms, while the echo signal is stored for further analyses, to be performed using dedicated software or, after relevant conversion, in arbitrary programming environment1. The presented data analysis is illustrated by selected sample images recorded by the parametric echosounder and the side-scan sonar during Gdansk Bay sounding.

A Study to Interpret the Biological Significance of Behavior Associated with 3S Experimental Sonar Exposures

Science.gov (United States)

2015-09-30

species; 2.) quantitative comparison of behavior, and behavioral changes, during sonar presentation and playback of killer whale sounds across the 3S... foraging dives were pre-classified from the remaining dives first by determining a break-point depth in the depth versus duration relationship, and then...AIC point to divide dive depth versus duration relationships (Fig. 2). 50.8% of dives greater than 15m in depth were classified as foraging dives

Directionality of sperm whale sonar clicks and its relation to piston radiation theory

DEFF Research Database (Denmark)

Beedholm, K.; Møhl, Bertel

2006-01-01

This paper investigates the applicability to sperm whales of the theory of sound radiating from a piston. The theory is applied to a physical model and to a series of sperm whale clicks. Results show that wave forms of off-axis signals can be reproduced by convolving an on-axis signal...... with the spatial impulse response of a piston. The angle of a recorded click can be estimated as the angle producing the spatial impulse response that gives the best match with the observation when convolved with the on-axis wave form. It is concluded that piston theory applies to sperm whale sonar click emission....

Underwater Cylindrical Object Detection Using the Spectral Features of Active Sonar Signals with Logistic Regression Models

Directory of Open Access Journals (Sweden)

Yoojeong Seo

2018-01-01

Full Text Available The issue of detecting objects bottoming on the sea floor is significant in various fields including civilian and military areas. The objective of this study is to investigate the logistic regression model to discriminate the target from the clutter and to verify the possibility of applying the model trained by the simulated data generated by the mathematical model to the real experimental data because it is not easy to obtain sufficient data in the underwater field. In the first stage of this study, when the clutter signal energy is so strong that the detection of a target is difficult, the logistic regression model is employed to distinguish the strong clutter signal and the target signal. Previous studies have found that if the clutter energy is larger, false detection occurs even for the various existing detection schemes. For this reason, the discrete Fourier transform (DFT magnitude spectrum of acoustic signals received by active sonar is applied to train the model to distinguish whether the received signal contains a target signal or not. The goodness of fit of the model is verified in terms of receiver operation characteristic (ROC, area under ROC curve (AUC, and classification table. The detection performance of the proposed model is evaluated in terms of detection rate according to target to clutter ratio (TCR. Furthermore, the real experimental data are employed to test the proposed approach. When using the experimental data to test the model, the logistic regression model is trained by the simulated data that are generated based on the mathematical model for the backscattering of the cylindrical object. The mathematical model is developed according to the size of the cylinder used in the experiment. Since the information on the experimental environment including the sound speed, the sediment type and such is not available, once simulated data are generated under various conditions, valid simulated data are selected using 70% of the

Sonar gas flux estimation by bubble insonification: application to methane bubble flux from seep areas in the outer Laptev Sea

Science.gov (United States)

Leifer, Ira; Chernykh, Denis; Shakhova, Natalia; Semiletov, Igor

2017-06-01

Sonar surveys provide an effective mechanism for mapping seabed methane flux emissions, with Arctic submerged permafrost seepage having great potential to significantly affect climate. We created in situ engineered bubble plumes from 40 m depth with fluxes spanning 0.019 to 1.1 L s-1 to derive the in situ calibration curve (Q(σ)). These nonlinear curves related flux (Q) to sonar return (σ) for a multibeam echosounder (MBES) and a single-beam echosounder (SBES) for a range of depths. The analysis demonstrated significant multiple bubble acoustic scattering - precluding the use of a theoretical approach to derive Q(σ) from the product of the bubble σ(r) and the bubble size distribution where r is bubble radius. The bubble plume σ occurrence probability distribution function (Ψ(σ)) with respect to Q found Ψ(σ) for weak σ well described by a power law that likely correlated with small-bubble dispersion and was strongly depth dependent. Ψ(σ) for strong σ was largely depth independent, consistent with bubble plume behavior where large bubbles in a plume remain in a focused core. Ψ(σ) was bimodal for all but the weakest plumes. Q(σ) was applied to sonar observations of natural arctic Laptev Sea seepage after accounting for volumetric change with numerical bubble plume simulations. Simulations addressed different depths and gases between calibration and seep plumes. Total mass fluxes (Qm) were 5.56, 42.73, and 4.88 mmol s-1 for MBES data with good to reasonable agreement (4-37 %) between the SBES and MBES systems. The seepage flux occurrence probability distribution function (Ψ(Q)) was bimodal, with weak Ψ(Q) in each seep area well described by a power law, suggesting primarily minor bubble plumes. The seepage-mapped spatial patterns suggested subsurface geologic control attributing methane fluxes to the current state of subsea permafrost.

Monitoring the US ATLAS Network Infrastructure with perfSONAR-PS

CERN Document Server

McKee, S; The ATLAS collaboration; Laurens, P; Severini, H; Wlodek, T; Wolff, S; Zurawski, J

2012-01-01

Global scientific collaborations, such as ATLAS, continue to push the network requirements envelope. Data movement in this collaboration is routinely including the regular exchange of petabytes of datasets between the collection and analysis facilities in the coming years. These requirements place a high emphasis on networks functioning at peak efficiency and availability; the lack thereof could mean critical delays in the overall scientific progress of distributed data-intensive experiments like ATLAS. Network operations staff routinely must deal with problems deep in the infrastructure; this may be as benign as replacing a failing piece of equipment, or as complex as dealing with a multidomain path that is experiencing data loss. In either case, it is crucial that effective monitoring and performance analysis tools are available to ease the burden of management. We will report on our experiences deploying and using the perfSONAR-PS Performance Toolkit[8] at ATLAS sites in the United States. This software cr...

Object Classification in Semi Structured Enviroment Using Forward-Looking Sonar

Directory of Open Access Journals (Sweden)

Matheus dos Santos

2017-09-01

Full Text Available The submarine exploration using robots has been increasing in recent years. The automation of tasks such as monitoring, inspection, and underwater maintenance requires the understanding of the robot’s environment. The object recognition in the scene is becoming a critical issue for these systems. On this work, an underwater object classification pipeline applied in acoustic images acquired by Forward-Looking Sonar (FLS are studied. The object segmentation combines thresholding, connected pixels searching and peak of intensity analyzing techniques. The object descriptor extract intensity and geometric features of the detected objects. A comparison between the Support Vector Machine, K-Nearest Neighbors, and Random Trees classifiers are presented. An open-source tool was developed to annotate and classify the objects and evaluate their classification performance. The proposed method efficiently segments and classifies the structures in the scene using a real dataset acquired by an underwater vehicle in a harbor area. Experimental results demonstrate the robustness and accuracy of the method described in this paper.

Seafloor identification in sonar imagery via simulations of Helmholtz equations and discrete optimization

Science.gov (United States)

Engquist, Björn; Frederick, Christina; Huynh, Quyen; Zhou, Haomin

2017-06-01

We present a multiscale approach for identifying features in ocean beds by solving inverse problems in high frequency seafloor acoustics. The setting is based on Sound Navigation And Ranging (SONAR) imaging used in scientific, commercial, and military applications. The forward model incorporates multiscale simulations, by coupling Helmholtz equations and geometrical optics for a wide range of spatial scales in the seafloor geometry. This allows for detailed recovery of seafloor parameters including material type. Simulated backscattered data is generated using numerical microlocal analysis techniques. In order to lower the computational cost of the large-scale simulations in the inversion process, we take advantage of a pre-computed library of representative acoustic responses from various seafloor parameterizations.

On doing two things at once: dolphin brain and nose coordinate sonar clicks, buzzes and emotional squeals with social sounds during fish capture.

Science.gov (United States)

Ridgway, Sam; Samuelson Dibble, Dianna; Van Alstyne, Kaitlin; Price, DruAnn

2015-12-01

Dolphins fishing alone in open waters may whistle without interrupting their sonar clicks as they find and eat or reject fish. Our study is the first to match sound and video from the dolphin with sound and video from near the fish. During search and capture of fish, free-swimming dolphins carried cameras to record video and sound. A hydrophone in the far field near the fish also recorded sound. From these two perspectives, we studied the time course of dolphin sound production during fish capture. Our observations identify the instant of fish capture. There are three consistent acoustic phases: sonar clicks locate the fish; about 0.4 s before capture, the dolphin clicks become more rapid to form a second phase, the terminal buzz; at or just before capture, the buzz turns to an emotional squeal (the victory squeal), which may last 0.2 to 20 s after capture. The squeals are pulse bursts that vary in duration, peak frequency and amplitude. The victory squeal may be a reflection of emotion triggered by brain dopamine release. It may also affect prey to ease capture and/or it may be a way to communicate the presence of food to other dolphins. Dolphins also use whistles as communication or social sounds. Whistling during sonar clicking suggests that dolphins may be adept at doing two things at once. We know that dolphin brain hemispheres may sleep independently. Our results suggest that the two dolphin brain hemispheres may also act independently in communication. © 2015. Published by The Company of Biologists Ltd.

mos113_0401r.tif -- Side scan sonar image from survey effort HMPR-113-2004-01r in the Olympic Coast national marine sanctuary.

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — This side scan sonar imagery of the sea floor (50-80 m water depths) was mosaiced from acoustic data collected in 2004 aboard the NOAA ship McArthurII.A Klein System...

mos119_0601c.tif-- Side scan sonar image from survey effort HMPR-119-2006-01c in the Olympic Coast national marine sanctuary.

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — This side scan sonar imagery of the sea floor (120-210 m water depths) was mosaiced from acoustic data collected in April 2006 aboard the NOAA ship McArthurII. A...

mos113_0401d.tif -- Side scan sonar image from survey effort HMPR-113-2004-01d in the Olympic Coast national marine sanctuary.

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — This side scan sonar imagery of the sea floor (120-350 m water depths) was mosaiced from acoustic data collected in 2004 aboard the NOAA ship McArthurII. A Klein...

mos114_0402b.tif -- Side scan sonar image from survey effort HMPR-114-2004-02b in the Olympic Coast National Marine Sanctuary.

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — This side scan sonar image of the sea floor was mosaiced from data collected in August 2004 onboard the NOAA vesselTatoosh. An EG&G 272 side scan system was used...

mos119_0601a.tif-- Side scan sonar image from survey effort HMPR-119-2006-01a in the Olympic Coast national marine sanctuary.

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — This side scan sonar imagery of the sea floor (90-270 m water depths) was mosaiced from acoustic data collected in April 2006 aboard the NOAA ship McArthurII.A Klein...

mos118_0503a.tif -- Side scan sonar image from survey effort HMPR-118-2005-03a in the Olympic Coast national marine sanctuary.

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — This side scan sonar imagery of the sea floor (140-350 m water depths) was mosaiced from acoustic data collected in 2005 aboard the NOAA ship McArthurII. A Klein...

The relation between Arctic sea ice surface elevation and draft: A case study using coincident AUV sonar and airborne scanning laser

DEFF Research Database (Denmark)

Doble, Martin J.; Skourup, Henriette; Wadhams, Peter

2011-01-01

Data are presented from a survey by airborne scanning laser profilometer and an AUV-mounted, upward looking swath sonar in the spring Beaufort Sea. The air-snow (surface elevation) and water-ice (draft) surfaces were mapped at 1 x 1 m resolution over a 300 x 300 m area. Data were separated into l...

Acoustical characteristic predictions of a multi-layer system of a submerged vehicle hull mounted sonar simplified to an infinite planar model

Directory of Open Access Journals (Sweden)

Sung-Hee Kim

2012-06-01

Full Text Available Hull Mounted Sonar (HMS is a long range submerged vehicle's hull-mounted passive sonar system which detects low-frequency noise caused by machineries of enemy ships or submerged vehicles. The HMS needs a sound absorption /insulation multi-layer structure to shut out the self-noise from own machineries and to amplify signals from outside. Therefore, acoustic analysis of the multi-layer system should be performed when the HMS is designed. This paper simplified the HMS multi-layer system to be an infinite planar multi-layer model. Also, main excitations that influence the HMS were classified into mechanical, plane wave and turbulent flow excitation, and the investigations for each excitation were performed for various models. Stiffened multi-layer analysis for mechanical excitation and general multi-layer analysis for turbulent flow excitation were developed. The infinite planar multi-layer analysis was expected to be more useful for preliminary design stage of HMS system than the infinite cylindrical model because of short analysis time and easiness of parameter study.

Side-scan sonar techniques for the characterization of physical properties of artificial benthic habitats

Directory of Open Access Journals (Sweden)

Wen-Miin Tian

2011-01-01

Full Text Available Side-scan sonar observations conducted at Mito artificial habitat site in the southwest coast off Taiwan, documented the locations of both concrete cubic blocks (more than 10,000 units and scrapped steel boats (39 units deployed previously. Based on their geographic locations, the concrete cubic artificial reefs could be grouped into 14 reef sets. About 30% of the reefs were deployed out of the promulgated site area. For the purpose of artificial habitat site identification and fishery resources management, a database structure was designed to accommodate types and positions of reefs, information of reef sets, bathymetric contours, textures of bottom sediments and geomorphological characteristics. The effectiveness of Mito artificial habitat site was evaluated to be positive after the deployment of both concrete block reefs and steel boat reefs.Observações com sonar de varredura lateral ao largo de Mito na costa sudoeste de Taiwan, revelou a localização de mais de 10.000 blocos de concreto e 39 embarcações de ferro assentados previamente como recifes artificiais. Com base nas imagens obtidas, os cubos de concreto formam 14 grupos separados. Cerca de 30% das unidades de concreto foram assentadas fora das áreas previstas. Para a identificacão correta dos recifes artificiais e manejo adequado dos recursos pesqueiros, foi organizada uma base de dados com informações sobre forma, materiais e posição, e arranjo espacial das unidades recifais, bem como dados de batimetria, natureza do sedimento do fundo e geomorfologia. A eficiência dos recifes artificiais de Mito foi avaliada positivamente após o assentamento tanto das unidades de concreto quanto das embarcações de ferro.

hab108_0201_east.tif -- Side scan sonar image (East mosaic) from survey effort HMPR-108-2002-01 in the Olympic Coast national marine sanctuary.

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — This side scan sonar image of the sea floor (120-350 m water depths) was mosaiced from data collected in 2002.An Edgetech DF1000 side scan system was used for...

Deep sea animal density and size estimated using a Dual-frequency IDentification SONar (DIDSON) offshore the island of Hawaii

Science.gov (United States)

Giorli, Giacomo; Drazen, Jeffrey C.; Neuheimer, Anna B.; Copeland, Adrienne; Au, Whitlow W. L.

2018-01-01

Pelagic animals that form deep sea scattering layers (DSLs) represent an important link in the food web between zooplankton and top predators. While estimating the composition, density and location of the DSL is important to understand mesopelagic ecosystem dynamics and to predict top predators' distribution, DSL composition and density are often estimated from trawls which may be biased in terms of extrusion, avoidance, and gear-associated biases. Instead, location and biomass of DSLs can be estimated from active acoustic techniques, though estimates are often in aggregate without regard to size or taxon specific information. For the first time in the open ocean, we used a DIDSON sonar to characterize the fauna in DSLs. Estimates of the numerical density and length of animals at different depths and locations along the Kona coast of the Island of Hawaii were determined. Data were collected below and inside the DSLs with the sonar mounted on a profiler. A total of 7068 animals were counted and sized. We estimated numerical densities ranging from 1 to 7 animals/m3 and individuals as long as 3 m were detected. These numerical densities were orders of magnitude higher than those estimated from trawls and average sizes of animals were much larger as well. A mixed model was used to characterize numerical density and length of animals as a function of deep sea layer sampled, location, time of day, and day of the year. Numerical density and length of animals varied by month, with numerical density also a function of depth. The DIDSON proved to be a good tool for open-ocean/deep-sea estimation of the numerical density and size of marine animals, especially larger ones. Further work is needed to understand how this methodology relates to estimates of volume backscatters obtained with standard echosounding techniques, density measures obtained with other sampling methodologies, and to precisely evaluate sampling biases.

Echolocating bats emit a highly directional sonar sound beam in the field

DEFF Research Database (Denmark)

Surlykke, Annemarie; Boel Pedersen, Simon; Jakobsen, Lasse

2009-01-01

Bats use echolocation or biosonar to navigate and find prey at night. They emit short ultrasonic calls and listen for reflected echoes. The beam width of the calls is central to the function of the sonar, but directionality of echolocation calls has never been measured from bats flying in the wild....... We used a microphone array to record sounds and determine horizontal directionality for echolocation calls of the trawling Daubenton's bat, Myotis daubentonii, flying over a pond in its natural habitat. Myotis daubentonii emitted highly directional calls in the field. Directionality increased...... and directionality can be explained by the simple piston model. The model also suggests that the increase in the emitted intensity in the field is caused by the increased directionality, focusing sound energy in the forward direction. The bat may increase directionality by opening the mouth wider to emit a louder...

Higher-Order Statistics for the Detection of Small Objects in a Noisy Background Application on Sonar Imaging

Directory of Open Access Journals (Sweden)

M. Amate

2007-01-01

Full Text Available An original algorithm for the detection of small objects in a noisy background is proposed. Its application to underwater objects detection by sonar imaging is addressed. This new method is based on the use of higher-order statistics (HOS that are locally estimated on the images. The proposed algorithm is divided into two steps. In a first step, HOS (skewness and kurtosis are estimated locally using a square sliding computation window. Small deterministic objects have different statistical properties from the background they are thus highlighted. The influence of the signal-to-noise ratio (SNR on the results is studied in the case of Gaussian noise. Mathematical expressions of the estimators and of the expected performances are derived and are experimentally confirmed. In a second step, the results are focused by a matched filter using a theoretical model. This enables the precise localization of the regions of interest. The proposed method generalizes to other statistical distributions and we derive the theoretical expressions of the HOS estimators in the case of a Weibull distribution (both when only noise is present or when a small deterministic object is present within the filtering window. This enables the application of the proposed technique to the processing of synthetic aperture sonar data containing underwater mines whose echoes have to be detected and located. Results on real data sets are presented and quantitatively evaluated using receiver operating characteristic (ROC curves.

77 FR 27720 - Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to...

Science.gov (United States)

2012-05-11

...-injurious) thresholds for underwater sound sources (except explosives and tactical active sonar) based on... this recommendation as a mitigation measure to be impracticable for both economic and practical reasons... vessel activity, Apache will follow NMFS' Marine Mammal Viewing Guidelines and Regulations and will alter...

Experiences from using Autonomous Underwater Vehicles and Synthetic Aperture Sonar for Sediment and Habitat Mapping

Science.gov (United States)

Thorsnes, T.; Bjarnadóttir, L. R.

2017-12-01

Emerging platforms and tools like autonomous underwater vehicles and synthetic aperture sonars provide interesting opportunities for making seabed mapping more efficient and precise. Sediment grain-size maps are an important product in their own right and a key input for habitat and biotope maps. National and regional mapping programmes are tasked with mapping large areas, and survey efficiency, data quality, and resulting map confidence are important considerations when selecting the mapping strategy. Since 2005, c. 175,000 square kilometres of the Norwegian continental shelf and continental slope has been mapped with respect to sediments, habitats and biodiversity, and pollution under the MAREANO programme (www.mareano.no). At present the sediment mapping is based on a combination of ship-borne multibeam bathymetry and backscatter, visual documentation using a towed video platform, and grab sampling. We have now tested a new approach, using an Autonomous Underwater Vehicle (AUV) as the survey platform for the collection of acoustic data (Synthetic Aperture Sonar (SAS), EM2040 bathymetry and backscatter) and visual data (still images using a TFish colour photo system). This pilot project was conducted together the Norwegian Hydrographic Service, the Institute of Marine Research (biology observations) and the Norwegian Defence Research Establishment (operation of ship and AUV). The test site reported here is the Vesterdjupet area, offshore Lofoten, northern Norway. The water depth is between 170 and 300 metres, with sediments ranging from gravel, cobbles and boulders to sandy mud. A cold-water coral reef, associated with bioclastic sediments was also present in the study area. The presentation will give an overview of the main findings and experiences gained from this pilot project with a focus on geological mapping and will also discuss the relevance of AUV-based mapping to large-area mapping programmes like MAREANO.

mos115_0403.TIF -- Multibeam backscatter sonar image for the nearshore Cape Flattery area: Data from survey effort HMPR-115-2004-03 in the Olympic Coast national marine sanctuary.

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — This multibeam backscatter sonar image of the sea floor (0-200 m water depths) was mosaiced from data collected fromvarious mapping efforts each October from...

75 FR 64507 - Taking and Importing Marine Mammals; Military Training Activities Conducted Within the Gulf of...

Science.gov (United States)

2010-10-19

... shallow and deep water. However, instead of using an explosive AN/SSQ-110A as an impulsive source for the... sensor and processing systems. In concept, the simplest active sonars emit omni-directional pulses... ASW acoustic processing and sonobuoy types that are deployed in pairs. The EER/IEER system's active...

Optimal predator risk assessment by the sonar-jamming arctiine moth Bertholdia trigona.

Directory of Open Access Journals (Sweden)

Aaron J Corcoran

Full Text Available Nearly all animals face a tradeoff between seeking food and mates and avoiding predation. Optimal escape theory holds that an animal confronted with a predator should only flee when benefits of flight (increased survival outweigh the costs (energetic costs, lost foraging time, etc.. We propose a model for prey risk assessment based on the predator's stage of attack. Risk level should increase rapidly from when the predator detects the prey to when it commits to the attack. We tested this hypothesis using a predator--the echolocating bat--whose active biosonar reveals its stage of attack. We used a prey defense--clicking used for sonar jamming by the tiger moth Bertholdia trigona--that can be readily studied in the field and laboratory and is enacted simultaneously with evasive flight. We predicted that prey employ defenses soon after being detected and targeted, and that prey defensive thresholds discriminate between legitimate predatory threats and false threats where a nearby prey is attacked. Laboratory and field experiments using playbacks of ultrasound signals and naturally behaving bats, respectively, confirmed our predictions. Moths clicked soon after bats detected and targeted them. Also, B. trigona clicking thresholds closely matched predicted optimal thresholds for discriminating legitimate and false predator threats for bats using search and approach phase echolocation--the period when bats are searching for and assessing prey. To our knowledge, this is the first quantitative study to correlate the sensory stimuli that trigger defensive behaviors with measurements of signals provided by predators during natural attacks in the field. We propose theoretical models for explaining prey risk assessment depending on the availability of cues that reveal a predator's stage of attack.

Optimal Predator Risk Assessment by the Sonar-Jamming Arctiine Moth Bertholdia trigona

Science.gov (United States)

Corcoran, Aaron J.; Wagner, Ryan D.; Conner, William E.

2013-01-01

Nearly all animals face a tradeoff between seeking food and mates and avoiding predation. Optimal escape theory holds that an animal confronted with a predator should only flee when benefits of flight (increased survival) outweigh the costs (energetic costs, lost foraging time, etc.). We propose a model for prey risk assessment based on the predator's stage of attack. Risk level should increase rapidly from when the predator detects the prey to when it commits to the attack. We tested this hypothesis using a predator – the echolocating bat – whose active biosonar reveals its stage of attack. We used a prey defense – clicking used for sonar jamming by the tiger moth Bertholdia trigona– that can be readily studied in the field and laboratory and is enacted simultaneously with evasive flight. We predicted that prey employ defenses soon after being detected and targeted, and that prey defensive thresholds discriminate between legitimate predatory threats and false threats where a nearby prey is attacked. Laboratory and field experiments using playbacks of ultrasound signals and naturally behaving bats, respectively, confirmed our predictions. Moths clicked soon after bats detected and targeted them. Also, B. trigona clicking thresholds closely matched predicted optimal thresholds for discriminating legitimate and false predator threats for bats using search and approach phase echolocation – the period when bats are searching for and assessing prey. To our knowledge, this is the first quantitative study to correlate the sensory stimuli that trigger defensive behaviors with measurements of signals provided by predators during natural attacks in the field. We propose theoretical models for explaining prey risk assessment depending on the availability of cues that reveal a predator's stage of attack. PMID:23671686

Using data crawlers and semantic Web to build financial XBRL data generators: the SONAR extension approach.

Science.gov (United States)

Rodríguez-García, Miguel Ángel; Rodríguez-González, Alejandro; Colomo-Palacios, Ricardo; Valencia-García, Rafael; Gómez-Berbís, Juan Miguel; García-Sánchez, Francisco

2014-01-01

Precise, reliable and real-time financial information is critical for added-value financial services after the economic turmoil from which markets are still struggling to recover. Since the Web has become the most significant data source, intelligent crawlers based on Semantic Technologies have become trailblazers in the search of knowledge combining natural language processing and ontology engineering techniques. In this paper, we present the SONAR extension approach, which will leverage the potential of knowledge representation by extracting, managing, and turning scarce and disperse financial information into well-classified, structured, and widely used XBRL format-oriented knowledge, strongly supported by a proof-of-concept implementation and a thorough evaluation of the benefits of the approach.

Using Data Crawlers and Semantic Web to Build Financial XBRL Data Generators: The SONAR Extension Approach

Directory of Open Access Journals (Sweden)

Miguel Ángel Rodríguez-García

2014-01-01

Full Text Available Precise, reliable and real-time financial information is critical for added-value financial services after the economic turmoil from which markets are still struggling to recover. Since the Web has become the most significant data source, intelligent crawlers based on Semantic Technologies have become trailblazers in the search of knowledge combining natural language processing and ontology engineering techniques. In this paper, we present the SONAR extension approach, which will leverage the potential of knowledge representation by extracting, managing, and turning scarce and disperse financial information into well-classified, structured, and widely used XBRL format-oriented knowledge, strongly supported by a proof-of-concept implementation and a thorough evaluation of the benefits of the approach.

Using Data Crawlers and Semantic Web to Build Financial XBRL Data Generators: The SONAR Extension Approach

Science.gov (United States)

Rodríguez-García, Miguel Ángel; Rodríguez-González, Alejandro; Valencia-García, Rafael; Gómez-Berbís, Juan Miguel

2014-01-01

Precise, reliable and real-time financial information is critical for added-value financial services after the economic turmoil from which markets are still struggling to recover. Since the Web has become the most significant data source, intelligent crawlers based on Semantic Technologies have become trailblazers in the search of knowledge combining natural language processing and ontology engineering techniques. In this paper, we present the SONAR extension approach, which will leverage the potential of knowledge representation by extracting, managing, and turning scarce and disperse financial information into well-classified, structured, and widely used XBRL format-oriented knowledge, strongly supported by a proof-of-concept implementation and a thorough evaluation of the benefits of the approach. PMID:24587726

Factoring polynomials over arbitrary finite fields

NARCIS (Netherlands)

Lange, T.; Winterhof, A.

2000-01-01

We analyse an extension of Shoup's (Inform. Process. Lett. 33 (1990) 261–267) deterministic algorithm for factoring polynomials over finite prime fields to arbitrary finite fields. In particular, we prove the existence of a deterministic algorithm which completely factors all monic polynomials of

Shaping Influences on the Leadership of Genghis Khan, George Washington, and Nelson Mandela: Applications for Educators

Science.gov (United States)

Bongila, Jean-Pierre

2011-01-01

Using a prosopographical methodology this study examines common leadership influences that might have existed among Genghis Khan, George Washington, and Nelson Mandela. Shoup (2005) suggests that the following seven influences have contributed to nurturing the leadership of 12 renowned individuals: involved parents, happy childhood, formal,…

Evidence of mud diapirism and coral colonies in the ionian sea (central mediterranean from high resolution chirp sonar survey

Directory of Open Access Journals (Sweden)

C. Corselli

2006-06-01

Full Text Available A chirp sonar survey in the Ionian Sea investigated the Calabrian margin, the Calabrian accretionary wedge, the Taranto Trench and the Apulian foreland. Shallow tectonics structures have been related to deeper ones, recognised on CROP seismic profiles. The identified echo characters have been compared with those described in the modern literature and have been related to different kinds of sediments, on the basis of core samples. Based on echo character and morphology we have recognised: 1 A widespread presence of mounds, up to 50 m high, occurring on the Apulian plateau as isolated mounds in the deepest zones (1600-800 m and in groups in the shallower ones (800-600 m; they have been interpreted as coral mounds, according to a recent discovery of living deep water coral colonies in this zone. 2 Some mud diapirs, isolated or in groups of two or three elements, widespread in the whole study area. In analogy of what has been observed on the Mediterranean Ridge, their presence suggests the activity of deep tectonic structures (thrusts and faults and a reduced thickness (or absence of Messinian evaporites in this part of the Ionian Sea.

Innovative method for optimizing Side-Scan Sonar mapping: The blind band unveiled

Science.gov (United States)

Pergent, Gérard; Monnier, Briac; Clabaut, Philippe; Gascon, Gilles; Pergent-Martini, Christine; Valette-Sansevin, Audrey

2017-07-01

Over the past few years, the mapping of Mediterranean marine habitats has become a priority for scientists, environment managers and stakeholders, in particular in order to comply with European directives (Water Framework Directive and Marine Strategy Framework Directive) and to implement legislation to ensure their conservation. Side-scan sonar (SSS) is recognised as one of the most effective tool for underwater mapping. However, interpretation of acoustic data (sonograms) requires extensive field calibration and the ground-truthing process remains essential. Several techniques are commonly used, with sampling methods involving grabs, scuba diving observations or Remotely Operated Vehicle (ROV) underwater video recordings. All these techniques are time consuming, expensive and only provide sporadic informations. In the present study, the possibility of coupling a camera with a SSS and acquiring underwater videos in a continuous way has been tested. During the 'PosidCorse' oceanographic survey carried out along the eastern coast of Corsica, optical and acoustic data were respectively obtained using a GoPro™ camera and a Klein 3000™ SSS. Thereby, five profiles were performed between 10 and 50 m depth, corresponding to more than 20 km of data acquisition. The vertical images recorded with the camera fixed under the SSS and positioned facing downwards provided photo mosaics of very good quality corresponding to the entire sonograms's blind band. From the photo mosaics, 94% of the different bottom types and main habitats have been identified; specific structures linked to hydrodynamics conditions, anthropic and biological activities have also been observed as well as the substrate on which the Posidonia oceanica meadow grows. The association between acoustic data and underwater videos has proved to be a non-destructive and cost-effective method for ground-truthing in marine habitats mapping. Nevertheless, in order to optimize the results over the next surveys

Monograph: Young Adulthood and Middle Age, 1989.

Science.gov (United States)

Monograph: Young Adulthood and Middle Age, 1989

1989-01-01

The inaugural volume of this serial contains 12 articles that represent a diverse population of counselors: (1) "Issues in Counseling Immigrants" (Linda Sheppard); (2) "Family Support and Starting a Small Business" (Michael Cusack and Peter Emerson); (3) "Professional Disillusionment: Crisis or Catalyst" (Kay Miller, Susan Cooper-Shoup and…

Using ground-penetrating radar and sidescan sonar to compare lake bottom geology in New England

Science.gov (United States)

Nesbitt, I. M.; Campbell, S. W.; Arcone, S. A.; Smith, S. M.

2017-12-01

Post-Laurentide Ice Sheet erosion and re-deposition has had a significant influence on the geomorphology of New England. Anthropogenic activities such as forestry, farming, and construction of infrastructure such as dams and associated lake reservoirs, has further contributed to near surface changes. Unfortunately, these surface dynamics are difficult to constrain, both in space and time. One analog that can be used to estimate erosion and deposition, lake basin sedimentation, is typically derived from lake bottom sediment core samples. Reliance on core records assumes that derived sedimentation rates are representative of the broader watershed, despite being only a single point measurement. Geophysical surveys suggest that this assumption can be highly erroneous and unrepresentative of an entire lake basin. Herein, we conducted ground-penetrating radar (GPR) and side-scan sonar (SSS) surveys of multiple lakes in Maine, New Hampshire, and Vermont which are representative of different basin types to estimate sedimentation rates since Laurentide retreat. Subsequent age constraints from cores on multiple GPR-imaged horizons could be used to refine estimates of sedimentation rate change caused by evolving physical, biological, and chemical processes that control erosion, transport, and re-deposition. This presentation will provide a summary of GPR and SSS data collection methods, assumptions and limitations, structural and surficial interpretations, and key findings from multiple lake basins in New England. Results show that GPR and SSS are efficient, cost effective, and relatively accurate tools for helping to constrain lake erosion and deposition processes.

Automatic classification techniques for type of sediment map from multibeam sonar data

Science.gov (United States)

Zakariya, R.; Abdullah, M. A.; Che Hasan, R.; Khalil, I.

2018-02-01

Sediment map can be important information for various applications such as oil drilling, environmental and pollution study. A study on sediment mapping was conducted at a natural reef (rock) in Pulau Payar using Sound Navigation and Ranging (SONAR) technology which is Multibeam Echosounder R2-Sonic. This study aims to determine sediment type by obtaining backscatter and bathymetry data from multibeam echosounder. Ground truth data were used to verify the classification produced. The method used to analyze ground truth samples consists of particle size analysis (PSA) and dry sieving methods. Different analysis being carried out due to different sizes of sediment sample obtained. The smaller size was analyzed using PSA with the brand CILAS while bigger size sediment was analyzed using sieve. For multibeam, data acquisition includes backscatter strength and bathymetry data were processed using QINSy, Qimera, and ArcGIS. This study shows the capability of multibeam data to differentiate the four types of sediments which are i) very coarse sand, ii) coarse sand, iii) very coarse silt and coarse silt. The accuracy was reported as 92.31% overall accuracy and 0.88 kappa coefficient.

Sea ice draft in the Weddell Sea, measured by upward looking sonars

Directory of Open Access Journals (Sweden)

A. Behrendt

2013-06-01

Full Text Available The presented database contains time-referenced sea ice draft values from upward looking sonar (ULS measurements in the Weddell Sea, Antarctica. The sea ice draft data can be used to infer the thickness of the ice. They were collected during the period 1990–2008. In total, the database includes measurements from 13 locations in the Weddell Sea and was generated from more than 3.7 million measurements of sea ice draft. The files contain uncorrected raw drafts, corrected drafts and the basic parameters measured by the ULS. The measurement principle, the data processing procedure and the quality control are described in detail. To account for the unknown speed of sound in the water column above the ULS, two correction methods were applied to the draft data. The first method is based on defining a reference level from the identification of open water leads. The second method uses a model of sound speed in the oceanic mixed layer and is applied to ice draft in austral winter. Both methods are discussed and their accuracy is estimated. Finally, selected results of the processing are presented. The data can be downloaded from doi:10.1594/PANGAEA.785565.

Archive of Side Scan Sonar and Swath Bathymetry Data collected during USGS Cruise 10CCT02 Offshore of Petit Bois Island Including Petit Bois Pass, Gulf Islands National Seashore, Mississippi, March 2010

Science.gov (United States)

Pfeiffer, William R.; Flocks, James G.; DeWitt, Nancy T.; Forde, Arnell S.; Kelso, Kyle; Thompson, Phillip R.; Wiese, Dana S.

2011-01-01

In March of 2010, the U.S. Geological Survey (USGS) conducted geophysical surveys offshore of Petit Bois Island, Mississippi, and Dauphin Island, Alabama (fig. 1). These efforts were part of the USGS Gulf of Mexico Science Coordination partnership with the U.S. Army Corps of Engineers (USACE) to assist the Mississippi Coastal Improvements Program (MsCIP) and the Northern Gulf of Mexico (NGOM) Ecosystem Change and Hazards Susceptibility Project by mapping the shallow geologic stratigraphic framework of the Mississippi Barrier Island Complex. These geophysical surveys will provide the data necessary for scientists to define, interpret, and provide baseline bathymetry and seafloor habitat for this area and to aid scientists in predicting future geomorphological changes of the islands with respect to climate change, storm impact, and sea-level rise. Furthermore, these data will provide information for barrier island restoration, particularly in Camille Cut, and protection for the historical Fort Massachusetts on Ship Island, Mississippi. For more information please refer to http://ngom.usgs.gov/gomsc/mscip/index.html. This report serves as an archive of the processed swath bathymetry and side scan sonar data (SSS). Data products herein include gridded and interpolated surfaces, seabed backscatter images, and ASCII x,y,z data products for both swath bathymetry and side scan sonar imagery. Additional files include trackline maps, navigation files, GIS files, Field Activity Collection System (FACS) logs, and formal FGDC metadata. Scanned images of the handwritten and digital FACS logs are also provided as PDF files. Refer to the Acronyms page for expansion of acronyms and abbreviations used in this report.

Side-Scan Sonar Image Mosaic Using Couple Feature Points with Constraint of Track Line Positions

Directory of Open Access Journals (Sweden)

Jianhu Zhao

2018-06-01

Full Text Available To obtain large-scale seabed surface image, this paper proposes a side-scan sonar (SSS image mosaic method using couple feature points (CFPs with constraint of track line positions. The SSS geocoded images are firstly used to form a coarsely mosaicked one and the overlapping areas between adjacent strip images can be determined based on geographic information. Inside the overlapping areas, the feature point (FP detection and registration operation are adopted for both strips. According to the detected CFPs and track line positions, an adjustment model is established to accommodate complex local distortions as well as ensure the global stability. This proposed method effectively solves the problem of target ghosting or dislocation and no accumulated errors arise in the mosaicking process. Experimental results show that the finally mosaicked image correctly reflects the object distribution, which is meaningful for understanding and interpreting seabed topography.

New sidescan sonar and gravity evidence that the Nova-Canton Trough is a fracture zone

Science.gov (United States)

Joseph, Devorah; Taylor, Brian; Shor, Alexander N.

1992-05-01

A 1990 sidescan sonar survey in the eastern region of the Nova-Canton Trough mapped 138°-striking abyssal-hill fabric trending into 70°-striking trough structures. The location and angle of intersection of the abyssal hills with the eastern Nova-Canton Trough effectively disprove a spreading-center origin of this feature. Free-air gravity anomalies derived from satellite altimetry data show continuity, across the Line Islands, of the Nova-Canton Trough with the Clipperton Fracture Zone. The Canton-Clipperton trend is copolar, about a pole at 30°S, 152°W, with other coeval Pacific-Farallon fracture-zone segments, from the Pau to Marquesas fracture zones. This copolarity leads us to postulate a Pacific-Farallon spreading pattern for the magnetic quiet zone region north and east of the Manihiki Plateau, with the Nova-Canton Trough originating as a transform fault in this system.

Distributary channel meandering and bifurcation patterns on the Amazon deep-sea fan as revealed by long-range side-scan sonar (GLORIA)

Science.gov (United States)

Damuth, John E.; Kolla, Venkatarathnam; Flood, Roger D.; Kowsmann, Renato O.; Monteiro, Marcelo C.; Gorini, Marcus A.; Palma, Jorge J. C.; Belderson, Robert H.

1983-02-01

We mapped the distributary channel system of the Amazon deep-sea fan using the GLORIA long-range side-scan sonar. Individual channels were continuously traced for distances of up to 150 km. Channel bifurcation, although observed in only a few places, results in many cases from breaching of channel levees on the outsides of meander loops. Whether both channels remain active after branching or the original channel is abandoned by avulsion generally cannot be determined. The most striking channel characteristic is high sinuosity that results in extensive, intricate, often recurving meanders. Cutoffs and abandoned meander loops (oxbows) are observed in a few places. These meandering channels are comparable in size and appearance to those of mature fluvial systems on land, such as on the lower Mississippi River. The formation, maintenance, and modification of such extensive, well-developed meander systems would seem to require large volumes of continuous turbidity flow through the channels for relatively long time periods. This may challenge the traditional concept that channel formation and modification are accomplished by intermittent or sporadic turbidity-current events. *Present address: Superior Oil Company, 12401 Westheimer, Houston, Texas 77077

Utilization of sonar technology and microcontroller towards reducing aviation hazards during ground handling of aircraft

Science.gov (United States)

Khanam, Mosammat Samia; Biswas, Debasish; Rashid, Mohsina; Salam, Md Abdus

2017-12-01

Safety is one of the most important factors in the field of aviation. Though, modern aircraft are equipped with many instruments/devices to enhance the flight safety but it is seen that accidents/incidents are never reduced to zero. Analysis of the statistical summary of Commercial Jet Airplane accidents highlights that fatal accidents that occurred worldwide from 2006 through 2015 is 11% during taxing, loading/unloading, parking and towing. Human, handling the aircrafts is one of the most important links in aircraft maintenance and hence play a significant role in aviation safety. Effort has been made in this paper to obviate human error in aviation and outline an affordable system that monitors the uneven surface &obstacles for safe "towing in" and "towing out" of an aircraft by the ground crew. The system revolves around implementation of sonar technology by microcontroller. Ultrasonic sensors can be installed on aircraft wings and tail section to identify the uneven surface &obstacles ahead and provide early warning to the maintenance ground crews.

Adaptive vocal behavior drives perception by echolocation in bats

DEFF Research Database (Denmark)

Moss, Cynthia F; Chiu, Chen; Surlykke, Annemarie

2011-01-01

Echolocation operates through adaptive sensorimotor systems that collectively enable the bat to localize and track sonar objects as it flies. The features of sonar signals used by a bat to probe its surroundings determine the information available to its acoustic imaging system. In turn, the bat......'s perception of a complex scene guides its active adjustments in the features of subsequent sonar vocalizations. Here, we propose that the bat's active vocal-motor behaviors play directly into its representation of a dynamic auditory scene....

Detection Classification and Localisation of Marine Mammals Using the Passive Acoustic Capabilities of an LFAS System

NARCIS (Netherlands)

Robert, M.K.; IJsselmuide, S.P. van; Beerens, S.P.

2004-01-01

World-wide a concern is emerging about the influence of man-made sound on marine life and more particularly marine mammals, who fully depend on sound in their natural behaviour. High power active sonars systems like Low Frequency Active Sonar (LFAS) are at stake. These systems, designed for long

Use of side-scan sonar for estimations of Crassostrea brasiliana (Lamarck, 1819 stocks in subtidal banks on the south coast of Brazil

Directory of Open Access Journals (Sweden)

Gisela Geraldine Castilho Westphal

2016-03-01

Full Text Available Abstract Uncontrolled extractivism has led to a worldwide reduction in oyster stocks. The use of new and more efficient management tools for impacted environments must increase. The application of such tools requires previous biological and environmental knowledge of the resident populations of these bivalve mollusks. Technical difficulties are usually associated with studies of submerged oyster banks, and these difficulties result in a considerable lack of biological data on the oysters that inhabit subtidal zones. This study aimed to survey Crassostrea brasiliana (also known as C. gasar stocks in submerged banks and to evaluate a method with which to measure the extent of the banks and identify and quantify the oysters in the banks with the use of side-scan sonar. This study was conducted on 10 oysters banks located in the subtidal zone of Guaratuba Bay, on the south coast of Brazil. The prospection of all these banks was later validated by diving, and oyster samples (n = 20/bank were collected for species identification with a molecular method. Only one bank contained oysters that were generically classified as Crassostrea sp.; those in the remaining banks being identified as C. brasiliana. The prospected banks contained oysters of various sizes (average 1.5 m, n = 1,107 that were heterogeneously scattered in the riverbeds. The total number of oysters in the 10 sampled banks was estimated to be 21,159.13 oysters or 1 oyster/4.5 m², which represents a low oyster density in the study site. The results validate the use of side-scan sonar as an efficient means with which to prospect for oysters in banks located within subtidal zones.

Imaging beneath the skin of large tropical rivers: System morphodynamics of the Fly and Beni Rivers revealed by novel sub-surface sonar, deep coring, and modelling

Science.gov (United States)

Aalto, R. E.; Grenfell, M.; Lauer, J. W.

2011-12-01

Tropical rivers dominate Earth's fluvial fluxes for water, carbon, and mineral sediment. They are characterized by large channels and floodplains, old system histories, prolonged periods of flooding, and a clay-dominated sediment flux. However, the underlying bed & floodplain strata are poorly understood. Available data commonly stem from skin-deep approaches such as GIS analysis of imagery, shallow sampling & topographic profiling during lower river stages. Given the large temporal & spatial scales, new approaches are needed to see below lag deposits on mobile sandy beds & deep into expansive floodbasins. Furthermore, such data are needed to test whether we can interpret large tropical river morphology using analogies to small temperate systems. Systems in a dynamic state of response to sea level rise or an increase/contrast in sediment load would provide especially valuable insight. Last August we conducted a field campaign along the Fly and Strickland Rivers in Papua New Guinea (discharge ~5,350 CMS) and this September we investigated the Beni River in Northern Bolivia (discharge ~3,500 CMS). Results were obtained using a novel measurement method: a high-power (>4kW) dual-frequency SyQwest sub-bottom profiler customized to best image 10-20m below the river/lake bed in shallow water. We were able to distinguish sandy deposits from harder clay and silt lenses and also collected bed grab samples to verify our sonar results. Deep borehole samples (5-15m), bank samples, and push cores confirmed observations from the sonar profiling. We simultaneously collected side-scan sonar imagery plus DGPS records of water/bed elevations that could be used to parameterize numerical models. We have now analyzed these results in some detail. Findings for the Fly River include: 1) The prevalence of hard clay beneath the bed of the Lower Fly River and many locations along the Strickland River, retarding migration; 2) Unusual bed morphology along the lower Middle Fly River, where the

Characterization of Sea Lamprey stream entry using dual‐frequency identification sonar

Science.gov (United States)

McCain, Erin L.; Johnson, Nicholas; Hrodey, Peter J.; Pangle, Kevin L.

2018-01-01

Effective methods to control invasive Sea Lampreys Petromyzon marinus in the Laurentian Great Lakes often rely on knowledge of the timing of the Sea Lamprey spawning migration, which has previously been characterized using data gathered from traps. Most assessment traps are located many kilometers upstream from the river mouth, so less is known about when Sea Lampreys enter spawning streams and which environmental cues trigger their transition from lakes to rivers. To decide how to develop barriers and traps that target Sea Lampreys when they enter a stream, the stream entry of Sea Lampreys into a Lake Huron tributary during 2 years was assessed using dual‐frequency identification sonar (DIDSON). Sea Lampreys entered the stream in low densities when temperatures first reached 4°C, which was up to 6 weeks and a mean of 4 weeks earlier than when they were first captured in traps located upstream. The probability of stream entry was significantly affected by stream temperature and discharge, and stream entry timing peaked when stream temperatures rose to 12°C and discharge was high. Examination of the entry at a finer temporal resolution (i.e., minutes) indicated that Sea Lampreys did not exhibit social behavior (e.g., shoaling) during stream entry. Our findings indicate that Sea Lampreys may be vulnerable to alternative trap types near river mouths and hydraulic challenges associated with traditional traps. Also, seasonal migration barriers near stream mouths may need to be installed soon after ice‐out to effectively block the entire adult Sea Lamprey cohort from upstream spawning habitat.

Highly dynamic biological seabed alterations revealed by side scan sonar tracking of Lanice conchilega beds offshore the island of Sylt (German Bight)

Science.gov (United States)

Heinrich, C.; Feldens, P.; Schwarzer, K.

2017-06-01

Hydroacoustic surveys are common tools for habitat investigation and monitoring that aid in the realisation of the aims of the EU Marine Directives. However, the creation of habitat maps is difficult, especially when benthic organisms densely populate the seafloor. This study assesses the sensitivity of entropy and homogeneity image texture parameters derived from backscatter strength data to benthic habitats dominated by the tubeworm Lanice conchilega. Side scan sonar backscatter surveys were carried out in 2010 and 2011 in the German Bight (southern North Sea) at two sites approx. 20 km offshore of the island of Sylt. Abiotic and biotic seabed facies, such as sorted bedforms, areas of fine to medium sand and L. conchilega beds with different tube densities, were identified and characterised based on manual expert analysis and image texture analysis. Ground truthing was performed by grab sampling and underwater video observations. Compared to the manual expert analysis, the k- means classification of image textures proves to be a semi-automated method to investigate small-scale differences in a biologically altered seabed from backscatter data. The texture parameters entropy and homogeneity appear linearly interrelated with tube density, the former positively and the latter negatively. Reinvestigation of one site after 1 year showed an extensive change in the distribution of the L. conchilega-altered seabed. Such marked annual fluctuations in L. conchilega tube cover demonstrate the need for dense time series and high spatial coverage to meaningfully monitor ecological patterns on the seafloor with acoustic backscatter methods in the study region and similar settings worldwide, particularly because the sand mason plays a pivotal role in promoting biodiversity. In this context, image texture analysis provides a cost-effective and reproducible method to track biologically altered seabeds from side scan sonar backscatter signatures.

Modal Analysis of 27 mm Piezo Electric Plate for Small-Scale Underwater Sonar-Based Navigation

Directory of Open Access Journals (Sweden)

M. O. Afolayan

2013-01-01

Full Text Available This work presents progress towards the development of a small-scale, purely sonar-based navigation device for a robotic fish (~394 mm long. Aperture overloading of small (5 mm diameter ultrasonic transmitters does not allow them to be used effectively inside water. A test on a 27 mm diameter buzzer piezo plate shows promising performance under water at frequencies from 4.5 kHz to 80 kHz. ANSYS-based simulation was therefore used to find modal frequencies at higher frequencies so as to optimize this encouraging result. The simulation process also discovered several antiresonant frequencies such as 38.5 kHz, 54 kHz, and 57.5 kHz. All frequencies above the 8th harmonic (10,589.02 Hz are out of phase with the input load except a resonance frequency of 42.5 kHz and an antiresonance frequency of 56.5 kHz. Also, the first harmonic (1,648.73 Hz is the only frequency that gave a nodal deformation.

The Ecology and Environmental Impacts of Hydrilla

Science.gov (United States)

1992-10-15

in the dewatered areas. The drawdown also encouraged the germination of waterhyacinth seeds in the dewatered areas. Plant Analysis The productivity of...controls hydrilla in most situations. Sonar is the DowElanco registered trademark for products containing the active ingredient fluridone . Sonar aquatic

On the Advantage of Wideband Data Acquisition for Passive Diver Detection

NARCIS (Netherlands)

Fillinger, L.; Hunter, A.J.; Zampolli, M.; Clarijs, M.C.; Verolme, J.L.

2011-01-01

Situation awareness is an important component of security that justifies the equipment of sites with monitoring systems. For shore/harbour security, these systems are mostly composed of camera and radar, to monitor the land and the water surface, and of active sonar(s) when the underwater situation

Multi-platform operations in the Underwater Warfare Testbed (UWT)

NARCIS (Netherlands)

Keus, D; Benders, F.P.A.; Fitski, H.J.; Grootendorst, H.J.

2009-01-01

More than a decade ago, the long-term NATO scientific study “Maritime Operations in 2015” (MO 2015) identified the so-called multi-platform and co-operative multi-static Low Frequency Active Sonar (LFAS) concept, involving co-operative sonar data exchange between surface ships and submarines.

Geiger-Mode Avalanche Photodiode Arrays Integrated to All-Digital CMOS Circuits

Science.gov (United States)

2016-01-20

important in photon‐starved applications, such as night vision or high‐temporal‐resolution imaging. Interest in such scenarios lead to Lincoln’s...information of interest. Lincoln Laboratory’s long-term vision is to merge these functions, so that the work of information extraction is carried...M. Boroson, David O. Caplan, Constantine J. Digenis, David R. Hearn, and Ryan C. Shoup, "Design of an Optical Photon Counting Array Receiver System

Mapping coral and sponge habitats on a shelf-depth environment using multibeam sonar and ROV video observations: Learmonth Bank, northern British Columbia, Canada

Science.gov (United States)

Neves, Bárbara M.; Du Preez, Cherisse; Edinger, Evan

2014-01-01

Efforts to locate and map deep-water coral and sponge habitats are essential for the effective management and conservation of these vulnerable marine ecosystems. Here we test the applicability of a simple multibeam sonar classification method developed for fjord environments to map the distribution of shelf-depth substrates and gorgonian coral- and sponge-dominated biotopes. The studied area is a shelf-depth feature Learmonth Bank, northern British Columbia, Canada and the method was applied aiming to map primarily non-reef forming coral and sponge biotopes. Aside from producing high-resolution maps (5 m2 raster grid), biotope-substrate associations were also investigated. A multibeam sonar survey yielded bathymetry, acoustic backscatter strength and slope. From benthic video transects recorded by remotely operated vehicles (ROVs) six primary substrate types and twelve biotope categories were identified, defined by the primary sediment and dominant biological structure, respectively. Substrate and biotope maps were produced using a supervised classification mostly based on the inter-quartile range of the acoustic variables for each substrate type and biotope. Twenty-five percent of the video observations were randomly reserved for testing the classification accuracy. The dominant biotope-defining corals were red tree coral Primnoa pacifica and small styasterids, of which Stylaster parageus was common. Demosponges and hexactinellid sponges were frequently observed but no sponge reefs were observed. The substrate classification readily distinguished fine sediment, Sand and Bedrock from the other substrate types, but had greater difficulty distinguishing Bedrock from Boulders and Cobble. The biotope classification accurately identified Gardens (dense aggregations of sponges and corals) and Primnoa-dominated biotopes (67% accuracy), but most other biotopes had lower accuracies. There was a significant correspondence between Learmonth's biotopes and substrate types

Mapping the Gulf of Maine with side-scan sonar: A new bottom-type classification for complex seafloors

Science.gov (United States)

Barnhardt, W.A.; Kelley, J.T.; Dickson, S.M.; Belknap, D.F.

1998-01-01

The bedrock-framed seafloor in the northwestern Gulf of Maine is characterized by extreme changes in bathymetric relief and covered with a wide variety of surficial materials. Traditional methods of mapping cannot accurately represent the great heterogeneity of such a glaciated region. A new mapping scheme for complex seafloors, based primarily on the interpretation of side-scan sonar imagery, utilizes four easily recognized units: rock, gravel, sand and mud. In many places, however, the seafloor exhibits a complicated mixture or extremely 'patchy' distribution of the four basic units, which are too small to map individually. Twelve composite units, each a two-component mixture of the basic units, were established to represent this patchiness at a small scale (1:100,000). Using a geographic information system, these and all other available data (seismic profiles, grab samples, submersible dives and cores) were referenced to a common geographic base, superimposed on bathymetric contours and then integrated into surficial geologic maps of the regional inner continental shelf. This digital representation of the seafloor comprises a multidimensional, interactive model complete with explicit attributes (depth, bottom type) that allow for detailed analysis of marine environments.

Survey report of NOAA Ship McArthur II cruises AR-04-04, AR-05-05 and AR-06-03: habitat classification of side scan sonar imagery in support of deep-sea coral/sponge explorations at the Olympic Coast National Marine Sanctuary

Science.gov (United States)

Intelmann, Steven S.; Cochrane, Guy R.; Bowlby, C. Edward; Brancato, Mary Sue; Hyland, Jeffrey

2007-01-01

Habitat mapping and characterization has been defined as a high-priority management issue for the Olympic Coast National Marine Sanctuary (OCNMS), especially for poorly known deep-sea habitats that may be sensitive to anthropogenic disturbance. As a result, a team of scientists from OCNMS, National Centers for Coastal Ocean Science (NCCOS), and other partnering institutions initiated a series of surveys to assess the distribution of deep-sea coral/sponge assemblages within the sanctuary and to look for evidence of potential anthropogenic impacts in these critical habitats. Initial results indicated that remotely delineating areas of hard bottom substrate through acoustic sensing could be a useful tool to increase the efficiency and success of subsequent ROV-based surveys of the associated deep-sea fauna. Accordingly, side scan sonar surveys were conducted in May 2004, June 2005, and April 2006 aboard the NOAA Ship McArthur II to: (1) obtain additional imagery of the seafloor for broader habitat-mapping coverage of sanctuary waters, and (2) help delineate suitable deep-sea coral-sponge habitat, in areas of both high and low commercial-fishing activities, to serve as sites for surveying-in more detail using an ROV on subsequent cruises, Several regions of the sea floor throughout the OCNMS were surveyed and mosaicked at 1-meter pixel resolution. Imagery from the side scan sonar mapping efforts was integrated with other complementary data from a towed camera sled, ROVs, sedentary samples, and bathymetry records to describe geological and biological (where possible) aspects of habitat. Using a hierarchical deep-water marine benthic classification scheme (Greene et al. 1999), we created a preliminary map of various habitat polygon features for use in a geographical information system (GIS). This report provides a description of the mapping and groundtruthing efforts as well as results of the image classification procedure for each of the areas surveyed.

A Study on Value Added Tax for Business Enterprise Taxation - An Introduction

OpenAIRE

安部,知格

2002-01-01

In recent years，the argument whetter we should switch over the base of taxation for business enterprise from the income standard to other standards or not is rising. In these circumstances，as one of the other standards，the value-added tax has been taken up. The value-added tax appeared in Japan as the one which can be replaced income standard taxation for business enterprise by Shoup Mission in 1949. This paper considers the meaning of the value-added tax. Consequently，I think，the value-added...

A Threshold Pseudorandom Function Construction and Its Applications

DEFF Research Database (Denmark)

Nielsen, Jesper Buus

2002-01-01

We give the first construction of a practical threshold pseudo- random function.The protocol for evaluating the function is efficient enough that it can be used to replace random oracles in some protocols relying on such oracles. In particular, we show how to transform the efficient...... cryptographically secure Byzantine agreement protocol by Cachin, Kursawe and Shoup for the random oracle model into a cryptographically secure protocol for the complexity theoretic model without loosing efficiency or resilience,thereby constructing an efficient and optimally resilient Byzantine agreement protocol...

Vector Boolean Functions: applications in symmetric cryptography

OpenAIRE

Álvarez Cubero, José Antonio

2015-01-01

Esta tesis establece los fundamentos teóricos y diseña una colección abierta de clases C++ denominada VBF (Vector Boolean Functions) para analizar funciones booleanas vectoriales (funciones que asocian un vector booleano a otro vector booleano) desde una perspectiva criptográfica. Esta nueva implementación emplea la librería NTL de Victor Shoup, incorporando nuevos módulos que complementan a las funciones de NTL, adecuándolas para el análisis criptográfico. La clase fundamental que representa...

77 FR 6080 - Taking and Importing Marine Mammals; U.S. Navy's Atlantic Fleet Active Sonar Training

Science.gov (United States)

2012-02-07

... research, development, testing, and evaluation (RDT&E) activities to be conducted within the Atlantic Fleet... research activities conducted within the AFAST Study Area under regulations issued on January 22, 2009 (74... [[Page 6082

Science and Paranormal Phenomena

Energy Technology Data Exchange (ETDEWEB)

Noyes, H. Pierre

1999-06-03

In order to ground my approach to the study of paranormal phenomena, I first explain my operational approach to physics, and to the ''historical'' sciences of cosmic, biological, human, social and political evolution. I then indicate why I believe that ''paranormal phenomena'' might-but need not- fit into this framework. I endorse the need for a new theoretical framework for the investigation of this field presented by Etter and Shoup at this meeting. I close with a short discussion of Ted Bastin's contention that paranormal phenomena should be defined as contradicting physics.

Real-Time Classification of Seagrass Meadows on Flat Bottom with Bathymetric Data Measured by a Narrow Multibeam Sonar System

Directory of Open Access Journals (Sweden)

Masahiro Hamana

2016-01-01

Full Text Available Seagrass meadows, one of the most important habitats for many marine species, provide essential ecological services. Thus, society must conserve seagrass beds as part of their sustainable development efforts. Conserving these ecosystems requires information on seagrass distribution and relative abundance, and an efficient, accurate monitoring system. Although narrow multibeam sonar systems (NMBSs are highly effective in resolving seagrass beds, post-processing methods are required to extract key data. The purpose of this study was to develop a simple method capable of detecting seagrass meadows and estimating their relative abundance in real time using an NMBS. Because most seagrass meadows grow on sandy seafloors, we proposed a way of discriminating seagrass meadows from the sand bed. We classify meadows into three categories of relative seagrass abundance using the 95% confidence level of beam depths and the depth range of the beam depth. These are respectively two times the standard deviation of beam depths, and the difference between the shallowest and the deepest depths in a 0.5 × 0.5 m grid cell sampled with several narrow beams. We examined Zostera caulescens Miki, but this simple NMBS method of seagrass classification can potentially be used to map seagrass meadows with longer shoots of other species, such as Posidonia, as both have gas filled cavities.

Evaluation of a Single-Beam Sonar System to Map Seagrass at Two Sites in Northern Puget Sound, Washington

Science.gov (United States)

Stevens, Andrew W.; Lacy, Jessica R.; Finlayson, David P.; Gelfenbaum, Guy

2008-01-01

Seagrass at two sites in northern Puget Sound, Possession Point and nearby Browns Bay, was mapped using both a single-beam sonar and underwater video camera. The acoustic and underwater video data were compared to evaluate the accuracy of acoustic estimates of seagrass cover. The accuracy of the acoustic method was calculated for three classifications of seagrass observed in underwater video: bare (no seagrass), patchy seagrass, and continuous seagrass. Acoustic and underwater video methods agreed in 92 percent and 74 percent of observations made in bare and continuous areas, respectively. However, in patchy seagrass, the agreement between acoustic and underwater video was poor (43 percent). The poor agreement between the two methods in areas with patchy seagrass is likely because the two instruments were not precisely colocated. The distribution of seagrass at the two sites differed both in overall percent vegetated and in the distribution of percent cover versus depth. On the basis of acoustic data, seagrass inhabited 0.29 km2 (19 percent of total area) at Possession Point and 0.043 km2 (5 percent of total area) at the Browns Bay study site. The depth distribution at the two sites was markedly different. Whereas the majority of seagrass at Possession Point occurred between -0.5 and -1.5 m MLLW, most seagrass at Browns Bay occurred at a greater depth, between -2.25 and -3.5 m MLLW. Further investigation of the anthropogenic and natural factors causing these differences in distribution is needed.

Fitness Activity Recognition on Smartphones Using Doppler Measurements

Directory of Open Access Journals (Sweden)

Biying Fu

2018-05-01

Full Text Available Quantified Self has seen an increased interest in recent years, with devices including smartwatches, smartphones, or other wearables that allow you to monitor your fitness level. This is often combined with mobile apps that use gamification aspects to motivate the user to perform fitness activities, or increase the amount of sports exercise. Thus far, most applications rely on accelerometers or gyroscopes that are integrated into the devices. They have to be worn on the body to track activities. In this work, we investigated the use of a speaker and a microphone that are integrated into a smartphone to track exercises performed close to it. We combined active sonar and Doppler signal analysis in the ultrasound spectrum that is not perceivable by humans. We wanted to measure the body weight exercises bicycles, toe touches, and squats, as these consist of challenging radial movements towards the measuring device. We have tested several classification methods, ranging from support vector machines to convolutional neural networks. We achieved an accuracy of 88% for bicycles, 97% for toe-touches and 91% for squats on our test set.

Clean-up of the sea bed in the North Sea 1996

International Nuclear Information System (INIS)

1997-01-01

The petroleum activities in the North Sea have inadvertently caused some conflict with fishermen getting their trawls etc. into trash from littering of the sea bed. In the present report, the Norwegian Petroleum Directorate describes a clean-up operation undertaken in 1996 and paid by the State. A clean-up area of 1000 km 2 off Karmoey was selected. This area was mapped by side scan sonar along survey lines 300 m equidistant and a sonar range of 200 m. The sonar data were continuously interpreted by a geophysicist. Selected targets were then identified by ROV and eventually removed. Of the 59 targets examined, 11 were removed and dumped onshore. The largest part elevated was a chain cable of 9 tons. There is also a brief discussion of the compensation agreement with Norwegian fishermen. 4 figs

Ecosystem scale acoustic sensing reveals humpback whale behavior synchronous with herring spawning processes and re-evaluation finds no effect of sonar on humpback song occurrence in the Gulf of Maine in fall 2006.

Directory of Open Access Journals (Sweden)

Zheng Gong

Full Text Available We show that humpback-whale vocalization behavior is synchronous with peak annual Atlantic herring spawning processes in the Gulf of Maine. With a passive, wide-aperture, densely-sampled, coherent hydrophone array towed north of Georges Bank in a Fall 2006 Ocean Acoustic Waveguide Remote Sensing (OAWRS experiment, vocalizing whales could be instantaneously detected and localized over most of the Gulf of Maine ecosystem in a roughly 400-km diameter area by introducing array gain, of 18 dB, orders of magnitude higher than previously available in acoustic whale sensing. With humpback-whale vocalizations consistently recorded at roughly 2000/day, we show that vocalizing humpbacks (i were overwhelmingly distributed along the northern flank of Georges Bank, coinciding with the peak spawning time and location of Atlantic herring, and (ii their overall vocalization behavior was strongly diurnal, synchronous with the formation of large nocturnal herring shoals, with a call rate roughly ten-times higher at night than during the day. Humpback-whale vocalizations were comprised of (1 highly diurnal non-song calls, suited to hunting and feeding behavior, and (2 songs, which had constant occurrence rate over a diurnal cycle, invariant to diurnal herring shoaling. Before and during OAWRS survey transmissions: (a no vocalizing whales were found at Stellwagen Bank, which had negligible herring populations, and (b a constant humpback-whale song occurrence rate indicates the transmissions had no effect on humpback song. These measurements contradict the conclusions of Risch et al. Our analysis indicates that (a the song occurrence variation reported in Risch et al. is consistent with natural causes other than sonar, (b the reducing change in song reported in Risch et al. occurred days before the sonar survey began, and (c the Risch et al. method lacks the statistical significance to draw the conclusions of Risch et al. because it has a 98-100% false-positive rate

Imaging beneath the skin of large tropical rivers: Clay controls on system morphodynamics revealed by novel CHIRP sub-surface sonar and deep coring along the Fly and Strickland Rivers, Papua New Guinea (Invited)

Science.gov (United States)

Aalto, R. E.; Grenfell, M.; Lauer, J. W.

2010-12-01

Tropical rivers dominate Earth’s fluvial fluxes for water, carbon, and mineral sediment. They are characterized by large channels and floodplains, old system histories (in comparison to many temperate rivers), frequent and prolonged periods of flooding, and a clay-dominated sediment flux transported above a sandy bed. However, limited insight is available regarding the underlying bed & floodplain strata -- material that underpins system mobility and morphodynamics. Available data commonly stems from “skin-deep” approaches such as GIS analysis of imagery, shallow sampling of a surface veneer, & topographic profiling during lower river stages. Given the large temporal & spatial scales of such systems, new approaches are needed to see below lag deposits on mobile sandy beds & deep into expansive floodbasins. Furthermore, such data are needed to test whether we can usefully interpret large tropical river morphology using direct analogies to observations from small temperate sytems. Systems responding to sea level rise, pending avulsions, or an increase/contrast in sediment load would provide especially valuable insight. We conducted a field campaign along the Fly and Strickland Rivers in Papua New Guinea (discharge ~ 5,400 CMS). Immediate results were obtained using a dual-frequency CHIRP sub-bottom profiler optimized for fluvial environments, with which we were able to image 10-20m below the river/lake bed. We were able to distinguish sandy deposits from harder clay and silt lenses and also collected bed grab samples to verify our sonar results. Deep borehole samples (5-15m), push cores, and cutbank profiles of material strength confirmed observations from the sonar profiling. We simultaneously collected side-scan sonar imagery plus DGPS water/bed elevations. Findings include: 1) The prevalence of hard clay beneath the bed at many locations along the Lower Fly and Strickland Rivers, retarding migration; 2) Unusual bed morphology along the lower Middle Fly River

Study of reverberation pattern and its cancellation method in shallow water

Directory of Open Access Journals (Sweden)

Yang Shiuh-Kuang

2007-01-01

Full Text Available In shallow water, the primary limitation of the performance of active sonar is the reverberation that originates from volume and boundaries scattering as well as multi-path propagation. There­fore, reverberation cancelation is an important research topic for increasing the performance of active sonar in shallow water. In this research, the reverberation pattern is simulated using MAT­LAB software. The simulated frequency is 30-kHz in the research. There are two main aims of this work. The first is to create the signals that include the reverberation and the target. The second is to perform the reverberation cancelation for the active sonar in shallow water. The analysis of the reverberation for the spherical target is based on the propagation theory of image source, surface scattering of Rayleigh criterion of roughness, bottom scattering of Lambert’s Law, and multiple scattering. The signal containing the reverberation and the target is then compressed or enhanced by AGC (Automatic Gain Control. The echo of the target is then distinguished through the method of cross correlation. The follow­ing phenomena can be found: (a AGC can compress the signal in a specific dynamic range. (b cross correlation can be used to locate and distinguish the echoes of the target in a high reverberation environment.

Radar-Based Detection, Tracking and Speciation of Marine Mammals from Ships

National Research Council Canada - National Science Library

DeProspo, Douglas F; Mobley, Joseph; Hom, Wai; Carron, Mike

2005-01-01

...., those encountered during Navy-sponsored Low Frequency Active (LFA) sonar tests). Irrespective of the method of mammal injury or death, the act of injuring or killing whales can and does result in litigation proceedings...

Radar-Based Detection, Tracking and Speciation of Marine Mammals from Ships

National Research Council Canada - National Science Library

DeProspo, Douglas F; Mobley, Joseph; Hom, Wai; Carron, Mike

2004-01-01

...., those encountered during Navy-sponsored Low Frequency Active (LFA) sonar tests. Irrespective of the method of mammal injury or death, the act of injuring or killing whales can and does result in litigation proceedings...

Mechanical Systems Development and Integration for a Second Generation Robot Submarine.

Science.gov (United States)

1980-05-01

for various scientific ii endeavors. As such, there will be times when the sub- marine must be disassembled for maintenance. This chapter is intended...STBD Side Scan Array 2 Port Side Scan Array 3 Comunications Sonar 4 Pinger 5 Bottom Finding Sonar 6 Collision Avoidance Sonar 7 Gel Cell Battery 8

Assessment of bridge scour in the lower, middle, and upper Yangtze River estuary with riverbed sonar profiling techniques.

Science.gov (United States)

Zheng, Shuwei; Xu, Y Jun; Cheng, Heqin; Wang, Bo; Lu, Xuejun

2017-12-12

Riverbed scour of bridge piers can cause rapid loss in foundation strength, leading to sudden bridge collapse. This study used multi-beam echo sounders (Seabat 7125) to map riverbed surrounding the foundations of four major bridges in the lower, middle, and upper reaches of the 700-km Yangtze River Estuary (YRE) during June 2015 and September 2016. The high-resolution data were utilized to analyze the morphology of the bridge scour and the deformation of the wide-area riverbed (i.e., 5-18 km long and 1.3-8.3 km wide). In addition, previous bathymetric measurements collected in 1998, 2009, and 2013 were used to determine riverbed erosion and deposition at the bridge reaches. Our study shows that the scour depth surrounding the bridge foundations progressed up to 4.4-19.0 m in the YRE. Over the past 5-15 years, the total channel erosion in some river reaches was up to 15-17 m, possessing a threat to the bridge safety in the YRE. Tide cycles seemed to have resulted in significant variation in the scour morphology in the lower and middle YRE. In the lower YRE, the riverbed morphology displayed one long erosional ditch on both sides of the bridge foundations and a long-strip siltation area distributed upstream and downstream of the bridge foundations; in the middle YRE, the riverbed morphology only showed erosional morphology surrounding the bridge foundations. Large dunes caused deep cuts and steeper contours in the bridge scour. Furthermore, this study demonstrates that the high-resolution grid model formed by point cloud data of multi-beam echo sounders can clearly display the morphology of the bridge scour in terms of wide areas and that the sonar technique is a very useful tool in the assessment of bridge scours.

Source Array Support for Continuous Monitoring of Fish Population and Behavior by Instantaneous Continental-Shelf-Scale Imaging Using Ocean-Waveguide Acoustics

National Research Council Canada - National Science Library

Rynne, Ed; Gillette, David

2006-01-01

...) Multistatic ASW Capability Enhancement Program (MACE) as the source of underwater sounds to support active bi-static sonar capabilities for monitoring fish populations and behaviors during a September/October 2006 sea test off the coast of Maine...

Blue whales respond to anthropogenic noise.

Directory of Open Access Journals (Sweden)

Mariana L Melcón

Full Text Available Anthropogenic noise may significantly impact exposed marine mammals. This work studied the vocalization response of endangered blue whales to anthropogenic noise sources in the mid-frequency range using passive acoustic monitoring in the Southern California Bight. Blue whales were less likely to produce calls when mid-frequency active sonar was present. This reduction was more pronounced when the sonar source was closer to the animal, at higher sound levels. The animals were equally likely to stop calling at any time of day, showing no diel pattern in their sensitivity to sonar. Conversely, the likelihood of whales emitting calls increased when ship sounds were nearby. Whales did not show a differential response to ship noise as a function of the time of the day either. These results demonstrate that anthropogenic noise, even at frequencies well above the blue whales' sound production range, has a strong probability of eliciting changes in vocal behavior. The long-term implications of disruption in call production to blue whale foraging and other behaviors are currently not well understood.

The Extent of Restrictions on the Service of Active-Component Military Women

Science.gov (United States)

2012-01-01

from www.rand.org as a public service of the RAND Corporation. CHILDREN AND FAMILIES EDUCATION AND THE ARTS ENERGY AND ENVIRONMENT HEALTH AND...EN engineman, GM gunner’s mate, IT information systems, ET electronics technician, FC fire control, LS logistics spe- cialist, and CS culinary ...sonar technician rating. Women in non–submarine- specific ratings, such as YN yeoman, CS culinary specialist, and LS logistics specialist, are

High-resolution imaging methods in array signal processing

DEFF Research Database (Denmark)

Xenaki, Angeliki

in active sonar signal processing for detection and imaging of submerged oil contamination in sea water from a deep-water oil leak. The submerged oil _eld is modeled as a uid medium exhibiting spatial perturbations in the acoustic parameters from their mean ambient values which cause weak scattering...... of the incident acoustic energy. A highfrequency active sonar is selected to insonify the medium and receive the backscattered waves. High-frequency acoustic methods can both overcome the optical opacity of water (unlike methods based on electromagnetic waves) and resolve the small-scale structure...... of the submerged oil field (unlike low-frequency acoustic methods). The study shows that high-frequency acoustic methods are suitable not only for large-scale localization of the oil contamination in the water column but also for statistical characterization of the submerged oil field through inference...

Cleaning up the sea bed in the North Sea. 1994

International Nuclear Information System (INIS)

1995-01-01

The yearly raid was executed in an efficient way and without excess technical equipment interruptions. The vessel ''Lance'' owned by the Norwegian Sea Mapping Authorities which was used for the sonar mapping of the sea bed, was equipped with a Klein 531T side seeking sonar, a Simrad echo sounder of the type EM100 (multiray) and differential GPS navigation system. The executive committee has earlier expressed desire for a strengthening of the co-operation with the Norwegian Sea Mapping Authorities. The use of the vessel was in accordance with this wish. Stolt Comex Seaway A/S used the vessel M/S ''Seaway Commander'' and the underwater vessel ''Solo'' for the cleaning up project. The systems worked satisfactory during the entire operation. The cleaning operation was in 1994 carried out in 2 sections. The Petroleum Directorate agreed to letting the M/S ''Seaway Commander'' complete the project for Norsk Hydro at the Troll field in order to avoid delays in the Troll Oil project. In both periods there were good weather conditions. There was no extensive discontinuations due to the weather. During the two periods of 13,5 days 259 out of 370 positions were investigated visually through the systems. This is in average about 20 inspected positions a day. The reason for the high average is that the sailing distances are short between the positions and the findings corresponded to stated positions and sonar interpretations. Also this year there was installed a side seeking sonar in the underwater vessel which resulted in reduced investigation time at each aim. It was possible with this type of sonar to identify the goal quicker and to seek during transit between goals at moderate distances. Few articles with certainty contributed by the petroleum activities were retrieved

Laboratory Assessment of Commercially Available Ultrasonic Rangefinders

Science.gov (United States)

2015-11-01

HRLV-MaxSonar®-EZ4™, MB1220 XL-MaxSonar®- EZ2™, MB1240 XL-MaxSonar®-EZ4™, or MB1261 XL-MaxSonar®-EZL1™) and an Arduino Mega 2560* board to interface...measurements. The Arduino board and ultrasonic rangefinder were connected to the computer via universal serial bus (USB) cable, which acted as both...7.7593 x 10-92 4.3606 x 10-94 3.2443 x 10-68 8.2303 x 10-72 2.5376 x 10-26 19 Appendix B. Manufacturer’s list. Arduino LLC https

Some examples of marine mammal 'discomfort thresholds' in relation to man-made noise

NARCIS (Netherlands)

Verboom, W.C.; Kastelein, R.A.

2005-01-01

World-wide a concern exists about the influence of man-made noise on marine life and particularly on marine mammals and fish. One of the acoustic polluters of the world’s oceans is high-power active sonar, but also pile driving and seismic activities at sea are of concern with respect to animal

How man-made interference might cause gas bubble emboli in deep diving whales

Directory of Open Access Journals (Sweden)

Andreas eFahlman

2014-01-01

Full Text Available Recent cetacean mass strandings in close temporal and spatial association with sonar activity has raised the concern that anthropogenic sound may harm breath-hold diving marine mammals. Necropsy results of the stranded whales have shown evidence of bubbles in the tissues, similar to those in human divers suffering from decompression sickness (DCS. It has been proposed that changes in behavior or physiological responses during diving could increase tissue and blood N2 levels, thereby increasing DCS risk. Dive data recorded from sperm, killer, long-finned pilot, Blainville’s beaked and Cuvier’s beaked whales before and during exposure to low- (1-2 kHz and mid- (2-7 kHz frequency active sonar were used to estimate the changes in blood and tissue N2 tension (PN2. Our objectives were to determine if differences in 1 dive behavior or 2 physiological responses to sonar are plausible risk factors for bubble formation. The theoretical estimates indicate that all species may experience high N2 levels. However, unexpectedly, deep diving generally result in higher end-dive PN2 as compared with shallow diving. In this focused review we focus on three possible explanations: 1 We revisit an old hypothesis that CO2, because of its much higher diffusivity, form bubble precursors that continue to grow in N2 supersaturated tissues. Such a mechanism would be less dependent on the alveolar collapse depth but affected by elevated levels of CO2 following a burst of activity during sonar exposure. 2 During deep dives, a greater duration of time might be spent at depths where gas exchange continues as compared with shallow dives. The resulting elevated levels of N2 in deep diving whales might also make them more susceptible to anthropogenic disturbances. 3 Extended duration of dives even at depths beyond where the alveoli collapse could result in slow continuous accumulation of N2 in the adipose tissues that eventually becomes a liability.

78 FR 7049 - Takes of Marine Mammals Incidental to Specified Activities; U.S. Navy Training and Testing...

Science.gov (United States)

2013-01-31

... ship is by radar. Electromagnetic measurements of off- board electromagnetic signatures are also... detection of swimmers and other objects for the purposes of port security. Synthetic Aperture Sonars (SAS...-Impulsive ASW for Composite Anti-Submarine ASW 2,3,4; HF1; 5 Training Unit Warfare MF1,2,3,4,5,12. Exercise...

Detection to the DepositFan Occurring in the Sun Moon Lake Using Geophysical Sonar Data

Science.gov (United States)

Mimi, L.

2014-12-01

Located in central Taiwan, the Sun Moon Lake is an U-shaped basin with the waters capacity for 138.68 × 106m³. The water is input through two underground tunnels from the Wu-Jie dam in the upstream of the Zhuo-shui river. Although the Wu-Jie dam has been trying to keep the tunnels transporting clean water into the lake, the water is still mixed with muds. The silty water brings the deposits accumulating outwards from positions of the tunnel outlets resulting in a deposit fan formed in the lake. To monitor how the fan is accumulated is then very important in terms of environmental issue, tourism and electric power resources. Institute of Oceanography, National Taiwan University therefore conducted projects to use the multi-beam echo sounders to collect bathymetric data, and used the Chirp sub-bottom profiler to explore silted pattern inside the deposit fan. With these data, underwater topographic maps were plotted to observe the shape and internal structure of the fan. Moreover, two sets of data obtained in 2006 and 2012 were used to estimate the siltation magnitude and pattern in the six years period.The multi-beam sounder is Resons Seabat 9001s model; it collects 60 values in each of the swaths positioned by the DGPS method.The sub-bottom profiler is the EdgeTech 3100P Chirp Sonar, its acoustic wave frequency is in 2 ~ 16kHz. The data give the siltation amount in the Sun Moon Lake was around 3× 106 m³, which gives annual siltation rate at 5× 105 m³. The leading edge of the deposit fan has been expanded westwards 2 km from the water outlet since the tunnel was built 70 years ago; however, outside the deposit fan, the siltation shows insignificant amount on the water bottom.In the past few years the siltation mainly occurs outside in the east side of lake, more closer to the water outlets, the terrain had been increased from 744 m to 746 m (748.5 meters is stranded level of the lake).Observing sub-bottom profiler data, we can clearly see the location of the

Mega Scale Constructions and Art on Deep Gulf of Mexico Sonar Images Reveal Extensive Very Ancient Civilizations. Radical Holocene Climate Changes May Relate to Large Shifts in Gulf Surface Areas.

Science.gov (United States)

Allen, R. L.

2017-12-01

Enhanced images from subsea sonar scanning of the Western Gulf of Mexico have revealed quite large temples (4 km. in length), ruins of cities (14 km. by 11 km.), pyramids, amphitheaters, and many other structures. Some human faces have beards implying much earlier migrations of Europeans or North Africans. Several temples have paleo astronomy alignments and similarities to Stone Henge. Southern and Southwestern USA satellite land images display characteristics in common with several subsea designs. Water depths indicate that many structures go back about as far as the late Ice Age and are likely to be over ten thousand years old. Chronologies of civilizations, especially in North America will need to be seriously reconsidered. Greatly rising sea levels and radical climate changes must have helped to destroy relatively advanced cultures. Suprisingly deep water depths of many architectures provide evidence for closures within the Gulf of Mexico to open seas. Closures and openings may have influenced ancient radical climate swings between warmth and cooling as Gulf contributions to water temperatures contracted or expanded. These creations of very old and surprisingly advanced civilizations need protection.

Active listening for spatial orientation in a complex auditory scene.

Science.gov (United States)

Moss, Cynthia F; Bohn, Kari; Gilkenson, Hannah; Surlykke, Annemarie

2006-04-01

To successfully negotiate a complex environment, an animal must control the timing of motor behaviors in coordination with dynamic sensory information. Here, we report on adaptive temporal control of vocal-motor behavior in an echolocating bat, Eptesicus fuscus, as it captured tethered insects close to background vegetation. Recordings of the bat's sonar vocalizations were synchronized with high-speed video images that were used to reconstruct the bat's three-dimensional flight path and the positions of target and vegetation. When the bat encountered the difficult task of taking insects as close as 10-20 cm from the vegetation, its behavior changed significantly from that under open room conditions. Its success rate decreased by about 50%, its time to initiate interception increased by a factor of ten, and its high repetition rate "terminal buzz" decreased in duration by a factor of three. Under all conditions, the bat produced prominent sonar "strobe groups," clusters of echolocation pulses with stable intervals. In the final stages of insect capture, the bat produced strobe groups at a higher incidence when the insect was positioned near clutter. Strobe groups occurred at all phases of the wingbeat (and inferred respiration) cycle, challenging the hypothesis of strict synchronization between respiration and sound production in echolocating bats. The results of this study provide a clear demonstration of temporal vocal-motor control that directly impacts the signals used for perception.

Sonar Subsea Images of Large Temples, Mammoths, Giant Sloths. Huge Artwork Carvings, Eroded Cities, Human Images, and Paleo Astronomy Sites that Must be Over Ten Thousand Years Old.

Science.gov (United States)

Allen, R. L.

2016-12-01

Computer enhancing of side scanning sonar plots revealed images of massive art, apparent ruins of cities, and subsea temples. Some images are about four to twenty kilometers in length. Present water depths imply that many of the finds must have been created over ten thousand years ago. Also, large carvings of giant sloths, Ice Age elk, mammoths, mastodons, and other cold climate creatures concurrently indicate great age. In offshore areas of North America, some human faces have beards and what appear to be Caucasian characteristics that clearly contrast with the native tribal images. A few images have possible physical appearances associated with Polynesians. Contacts and at least limited migrations must have occurred much further in the ancient past than previously believed. Greatly rising sea levels and radical changes away from late Ice Age climates had to be devastating to very ancient civilizations. Many images indicate that these cultures were capable of construction and massive art at or near the technological level of the Old Kingdom in Egypt. Paleo astronomy is obvious in some plots. Major concerns are how to further evaluate, catalog, protect, and conserve the creations of those cultures.

Field calibration and validation of remote-sensing surveys

Science.gov (United States)

Pe'eri, Shachak; McLeod, Andy; Lavoie, Paul; Ackerman, Seth D.; Gardner, James; Parrish, Christopher

2013-01-01

The Optical Collection Suite (OCS) is a ground-truth sampling system designed to perform in situ measurements that help calibrate and validate optical remote-sensing and swath-sonar surveys for mapping and monitoring coastal ecosystems and ocean planning. The OCS system enables researchers to collect underwater imagery with real-time feedback, measure the spectral response, and quantify the water clarity with simple and relatively inexpensive instruments that can be hand-deployed from a small vessel. This article reviews the design and performance of the system, based on operational and logistical considerations, as well as the data requirements to support a number of coastal science and management projects. The OCS system has been operational since 2009 and has been used in several ground-truth missions that overlapped with airborne lidar bathymetry (ALB), hyperspectral imagery (HSI), and swath-sonar bathymetric surveys in the Gulf of Maine, southwest Alaska, and the US Virgin Islands (USVI). Research projects that have used the system include a comparison of backscatter intensity derived from acoustic (multibeam/interferometric sonars) versus active optical (ALB) sensors, ALB bottom detection, and seafloor characterization using HSI and ALB.

Continuous Active Sonar for Undersea Vehicles Final Report: Input of Factor Graphs into the Detection, Classification, and Localization Chain and Continuous Active SONAR in Undersea Vehicles

Science.gov (United States)

2015-12-31

determined unambiguously. 9 8 7 ~6 >-, (1l Q) 5 0 Q) E 4 f- 3 2 LFM Signal Transmitted 0 100 200 300 400 500 600 700 BOO 900 Frequency (Hz...200 300 400 500 600 700 BOO 900 1000 Time Ste.p (s) Figure 30: Plot of the difference ofthe velocity of the object being tracked/rom the velocities...0 0 _J 60 40 20 0 0 100 200 300 400 500 600 700 BOO 900 1000 Time Step (s) Figure 31 Plot of the difference of the location of the object

Inversion assuming weak scattering

DEFF Research Database (Denmark)

Xenaki, Angeliki; Gerstoft, Peter; Mosegaard, Klaus

2013-01-01

due to the complex nature of the field. A method based on linear inversion is employed to infer information about the statistical properties of the scattering field from the obtained cross-spectral matrix. A synthetic example based on an active high-frequency sonar demonstrates that the proposed...

Insights into Optimal Soft Start and Shutdown Procedures for Stationary or Moving Sound Sources

NARCIS (Netherlands)

Ainslie, M.A.; Benda-Beckmann, A.M. von

2012-01-01

To reduce the risk of impact on marine life of underwater sound generated by anthropogenic activities (such as offshore construction, seismic surveys and sonar searches), various mitigation measures are often put in place. Two commonly adopted mitigation measures are the soft start (or "ramp-up" –

Natural and anthropogenic events influence the soundscapes of four bays on Hawaii Island.

Science.gov (United States)

Heenehan, Heather L; Van Parijs, Sofie M; Bejder, Lars; Tyne, Julian A; Southall, Brandon L; Southall, Hugh; Johnston, David W

2017-11-15

The soundscapes of four bays along the Kona Coast of Hawaii Island were monitored between January 2011 and March 2013. Equivalent, unweighted sound pressure levels within standard 1/3rd-octave bands (dB re: 1μPa) were calculated for each recording. Sound levels increased at night and were lowest during the daytime when spinner dolphins use the bays to rest. A tsunami provided an opportunity to monitor the soundscape with little anthropogenic component. We detected a decrease in sound levels and variability in one of the busiest bays. During the daytime in the 3.15kHz 1/3rd octave band, we detected 92 loud outliers from vessels, aquaculture, and military mid-frequency active sonar. During one military mid-frequency active sonar event sound levels reached 45.8dB above median ambient noise levels. The differences found in the bays illustrate the importance of understanding soundscapes to effectively manage noise pollution in marine ecosystems. Copyright © 2017 Elsevier Ltd. All rights reserved.

A novel method of range measuring for a mobile robot based on multi-sensor information fusion

International Nuclear Information System (INIS)

Zhang Yi; Luo Yuan; Wang Jifeng

2005-01-01

The traditional measuring range for a mobile robot is based on a sonar sensor. Because of different working environments, it is very difficult to obtain high precision by using just one single method of range measurement. So, a hybrid sonar sensor and laser scanner method is put forward to overcome these shortcomings. A novel fusion model is proposed based on basic theory and a method of information fusion. An optimal measurement result has been obtained with information fusion from different sensors. After large numbers of experiments and performance analysis, a conclusion can be drawn that the laser scanner and sonar sensor method with multi-sensor information fusion have a higher precision than the single method of sonar. It can also be the same with different environments

Active listening for spatial orientation in a complex auditory scene.

Directory of Open Access Journals (Sweden)

Cynthia F Moss

2006-04-01

Full Text Available To successfully negotiate a complex environment, an animal must control the timing of motor behaviors in coordination with dynamic sensory information. Here, we report on adaptive temporal control of vocal-motor behavior in an echolocating bat, Eptesicus fuscus, as it captured tethered insects close to background vegetation. Recordings of the bat's sonar vocalizations were synchronized with high-speed video images that were used to reconstruct the bat's three-dimensional flight path and the positions of target and vegetation. When the bat encountered the difficult task of taking insects as close as 10-20 cm from the vegetation, its behavior changed significantly from that under open room conditions. Its success rate decreased by about 50%, its time to initiate interception increased by a factor of ten, and its high repetition rate "terminal buzz" decreased in duration by a factor of three. Under all conditions, the bat produced prominent sonar "strobe groups," clusters of echolocation pulses with stable intervals. In the final stages of insect capture, the bat produced strobe groups at a higher incidence when the insect was positioned near clutter. Strobe groups occurred at all phases of the wingbeat (and inferred respiration cycle, challenging the hypothesis of strict synchronization between respiration and sound production in echolocating bats. The results of this study provide a clear demonstration of temporal vocal-motor control that directly impacts the signals used for perception.

The Jellyfish: smart electro-active polymers for an autonomous distributed sensing node

Science.gov (United States)

Blottman, John B.; Richards, Roger T.

2006-05-01

The US Navy has recently placed emphasis on deployable, distributed sensors for Force Protection, Anti-Terrorism and Homeland Defense missions. The Naval Undersea Warfare Center has embarked on the development of a self-contained deployable node that is composed of electro-active polymers (EAP) for use in a covert persistent distributed surveillance system. Electro-Active Polymers (EAP) have matured to a level that permits their application in energy harvesting, hydrophones, electro-elastic actuation and electroluminescence. The problem to resolve is combining each of these functions into an autonomous sensing platform. The concept presented here promises an operational life several orders of magnitude beyond what is expected of a Sonobuoy due to energy conservation and harvesting, and at a reasonable cost. The embodiment envisioned is that of a deployed device resembling a jellyfish, made in most part of polymers, with the body encapsulating the necessary electronic processing and communications package and the tentacles of the jellyfish housing the sonar sensors. It will be small, neutrally buoyant, and will survey the water column much in the manner of a Cartesian Diver. By using the Electro-Active Polymers as artificial muscles, the motion of the jellyfish can be finely controlled. An increased range of detection and true node autonomy is achieved through volumetric array beamforming to focus the direction of interrogation and to null-out extraneous ambient noise.

Detection and Classification of Marine mammals using an LFAS system

NARCIS (Netherlands)

IJsselmuide, S.P. van; Beerend, S.P.

2004-01-01

World wide a concern is emerging about the influence of man-made sound in the sea on marine life, and particularly about high power active sonars systems. Most concern lies with marine mammals, which fully depend on sound in their natural behaviour (foraging, navigation and communication). One of

Echo and reverberation in a Pekeris waveguide by convolution and by the product rule

NARCIS (Netherlands)

Ainslie, M.A.

2013-01-01

The detection performance of an active sonar depends on the intensity of the signal (target echo) relative to that of a background of reverberation plus noise. The echo is calculated for a standard test problem by convolving the time-domain impulse response at the target position with itself. The

Oceanographic data collected during the EX1602 Mission System Shakedown/CAPSTONE Mapping on NOAA Ship OKEANOS EXPLORER in the North Pacific Ocean from 2016-02-12 to 2016-02-17 (NCEI Accession 0145342)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Operations used the ship's deep water mapping systems (Kongsberg EM302 multibeam sonar, EK60 split-beam fisheries sonars, Knudsen 3260 chirp sub-bottom profiler...

Okeanos Explorer (EX1703): Howland/Baker PRIMNM and PIPA (ROV/Mapping)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Operations will include the use of the ship's deep water mapping systems (Kongsberg EM302 multibeam sonar, EK60 split-beam fisheries sonars, Knudsen 3260 chirp...

Okeanos Explorer (EX1702): American Samoa Expedition: Suesuega o le Moana o Amerika Samoa (ROV/Mapping)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Operations will include the use of the ship's deep water mapping systems (Kongsberg EM302 multibeam sonar, EK60 split-beam fisheries sonars, Knudsen 3260 chirp...

Okeanos Explorer (EX1705): American Samoa, Kingman/Palmyra, Jarvis (ROV & Mapping)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Operations will include the use of the ship's deep water mapping systems (Kongsberg EM302 multibeam sonar, EK60 split-beam fisheries sonars, Knudsen 3260 chirp...

Okeanos Explorer (EX1706): Johnston Atoll (ROV/Mapping)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Operations will include the use of the ship's deep water mapping systems (Kongsberg EM302 multibeam sonar, EK60 split-beam fisheries sonars, Knudsen 3260 chirp...

Ultrasound -- Pelvis

Medline Plus

Full Text Available ... The principles are similar to sonar used by boats and submarines. The ultrasound image is immediately visible ... principles involved in the sonar used by bats, ships and fishermen. When a sound wave strikes an ...

Foreign Body Retrieval

Medline Plus

Full Text Available ... The principles are similar to sonar used by boats and submarines. The ultrasound image is immediately visible ... principles involved in the sonar used by bats, ships and fishermen. When a sound wave strikes an ...

Children's (Pediatric) Abdominal Ultrasound Imaging

Medline Plus

Full Text Available ... echoes from the tissues in the body. The principles are similar to sonar used by boats and ... work? Ultrasound imaging is based on the same principles involved in the sonar used by bats, ships ...

General Ultrasound Imaging

Medline Plus

Full Text Available ... echoes from the tissues in the body. The principles are similar to sonar used by boats and ... work? Ultrasound imaging is based on the same principles involved in the sonar used by bats, ships ...

Foreign Body Retrieval

Medline Plus

Full Text Available ... echoes from the tissues in the body. The principles are similar to sonar used by boats and ... rays. Ultrasound imaging is based on the same principles involved in the sonar used by bats, ships ...

Prostate Ultrasound

Medline Plus

Full Text Available ... echoes from the tissues in the body. The principles are similar to sonar used by boats and ... work? Ultrasound imaging is based on the same principles involved in the sonar used by bats, ships ...

Ultrasound -- Pelvis

Medline Plus

Full Text Available ... echoes from the tissues in the body. The principles are similar to sonar used by boats and ... work? Ultrasound imaging is based on the same principles involved in the sonar used by bats, ships ...

Sonohysterography

Medline Plus

Full Text Available ... echoes from the tissues in the body. The principles are similar to sonar used by boats and ... work? Ultrasound imaging is based on the same principles involved in the sonar used by bats, ships ...

Spatial distribution maps for benthic communities

DEFF Research Database (Denmark)

Sørensen, Per S.

1999-01-01

ecosystems, were selected. These species are supposed to be good indicators of marine ecosystem health. The hydroacoustic measurements comprise preprocessed echo sounder recordings and side-scan sonar data forming a large and unique collection of datasets based on 4 field campaigns in Øresund...... of the distribution maps and to be combined with biogeochemical models describing spatiotemporal population dynamics. Finally, the use of side-scan sonar data is illustrated in a data fusion exercise combining side-scan sonar data with the results based on echo sounder measurements. The feasible use of side......-scan sonar for mapping of benthic communities remains an open task to be studied in the future. The data processing methodology developed is a contribution to the emerging field of hydroacoustic marine biology. The method of penalised maximum pseudo-likelihood for estimation of the Ising model under a huge...

Okeanos Explorer (EX1606): CAPSTONE Wake Island Unit PRIMNM (ROV & Mapping)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Operations will use the ship’s deep water mapping systems (Kongsberg EM302 multibeam sonar, EK60 split-beam fisheries sonars, ADCPs, and Knudsen 3260 chirp...

Okeanos Explorer (EX1608): FY17 Ship and ROV Shakedown

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Operations will use the ship’s deep water mapping systems (Kongsberg EM302 multibeam sonar, EK60 split-beam fisheries sonars, ADCPs, and Knudsen 3260 chirp...

Okeanos Explorer (EX1602): Mission System Shakedown/CAPSTONE Mapping

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Operations will use the ship’s deep water mapping systems (Kongsberg EM302 multibeam sonar, EK60 split-beam fisheries sonars, Knudsen 3260 chirp sub-bottom...

Okeanos Explorer (EX1605L2): CAPSTONE CNMI and Mariana Trench MNM (Mapping)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Operations will use the ship’s deep water mapping systems (Kongsberg EM302 multibeam sonar, EK60 split-beam fisheries sonars, ADCPs, and Knudsen 3260 chirp...

Enhancement of heat and mass transfer by cavitation

International Nuclear Information System (INIS)

Zhang, Y N; Du, X Z; Xian, H Z; Zhang, Y N

2015-01-01

In this paper, a brief summary of effects of cavitation on the heat and mass transfer are given. The fundamental studies of cavitation bubbles, including its nonlinearity, rectified heat and mass diffusion, are initially introduced. Then selected topics of cavitation enhanced heat and mass transfer were discussed in details including whales stranding caused by active sonar activity, pool boiling heat transfer, oscillating heat pipe and high intensity focused ultrasound treatment

Adaptive beamforming for low frequency SAS imagery and bathymetry

NARCIS (Netherlands)

Hayes, M.P.; Hunter, A.J.

2012-01-01

Synthetic aperture side-scan sonar (SAS) is a mature technology for high-resolution sea floor imaging [1]. Interferometric synthetic aperture sonars (InSAS) use additional hydrophones in a vertical array for bathymetric mapping [2]. This has created high-resolution bathymetry in deep water

Okeanos Explorer (EX1701): Kingman/Palmyra, Jarvis (Mapping)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Operations will include the use of the ship’s deep water mapping systems (Kongsberg EM302 multibeam sonar, EK60 split-beam fisheries sonars, ADCPs, and Knudsen...

High-Resolution Seafloor Observations of an Active Mud Volcano Offshore SW Taiwan - Results of a Repeated Survey after Four Years

Science.gov (United States)

Hsu, H. H.; Chen, T. T.; Liu, C. S.; Su, C. C.; Paull, C. K.; Caress, D. W.; Gwiazda, R.; Chen, Y. H.

2017-12-01

Mud Volcano V (MV5) is an active submarine mud volcano sitting on top of a mud diapir ridge at water depths of 600 m in the active margin offshore of southwestern Taiwan. This cone-shape mud volcano is almost 3-km-wide, 200-m-high, with 9.5° slopes, and explosively ejects streams of mud every 1.5-3 minutes. It was first mapped in 2013 with MBARI's mapping AUV (autonomous underwater vehicle). In 2017, a repeated AUV mapping survey was conducted to see if significant bathymetric changes took place since 2013, and to investigate the fluxes of fluids that pass through diapiric structures in an active continental margin. In addition to high-resolution bathymetry (1-m-resolution), sub-bottom profiling and side-scan sonar data acquired by the AUV, and videos and samples collected by MBARI's miniROV, we also incorporate multichannel seismic reflection data and gravity core sample analyses in this study. AUV bathymetry data reveal that there are two gryphons on the eastern slope of MV5. In the 2017 survey the mapped sizes of the two side cones were 80 m wide, 35 m long, 20 m relief and 40 m wide, 40 m long, 12 m relief, respectively. Comparing the bathymetry mapped in the 2017 AUV survey with that surveyed in 2013, no obvious overall morphological changes in MV5 are detected, except around the two gryphons. In the time period between the surveys, due to venting of mud from the two gryphons, two series of flow deposits which can be up to 5 meters thick are observed along the slope in the east side of both gryphons. The center depressions of these two gryphons have increased by 1-5 meters depth in their west side. Seismic and sub-bottom profiles reveal amplitude anomalies in the sub-strata of MV5 which indicate possible fluid migration paths of mud flows from deep. The trace of mud flow from the top of MV5 to its foot can be delineated from the side-scan sonar images. On the basis of 210Pbex chronology dating method, the sedimentation rate on the surface of MV5 is very slow

Fluctuations in Echo Level Associated with Changes in Target Aspect and Target Frequency Response (abstract only)

NARCIS (Netherlands)

Zampolli, M.; Ainslie, M.A.; Zon, T. van

2011-01-01

Ping-to-ping variations in echo level can be caused by time variations in sonar parameters (source level, orientation), target aspect, relative and absolute motion of sonar and target, and time varying environment (e.g. surface waves). Quantifying and understanding such fluctuations are important,

Sensor Data Fusion

DEFF Research Database (Denmark)

Plascencia, Alfredo; Stepán, Petr

2006-01-01

The main contribution of this paper is to present a sensor fusion approach to scene environment mapping as part of a Sensor Data Fusion (SDF) architecture. This approach involves combined sonar array with stereo vision readings.  Sonar readings are interpreted using probability density functions...

The Delphinus array for passive marine mammal detection

NARCIS (Netherlands)

Sheldon-Robert, M.K.; Beerens, S.P.; Lam, F.P.A.

2008-01-01

To protect marine mammals from potential negative impacts of high-power sound from tactical sonar, the use of passive acoustic monitoring prior and during sonar exercises is a possible non-intrusive solution for the monitoring requirements for naval forces. Particularly deep-diving beaked whales

Adaptive Beamforming Algorithms for Tow Ship Noise Canceling

NARCIS (Netherlands)

Robert, M.K.; Beerens, S.P.

2002-01-01

In towed array sonar, the directional noise originating from the tow ship, mainly machinery and hydrodynamic noise, often limits the sonar performance. When processed with classical beamforming techniques, loud tow ship noise induces high sidelobes that may hide detection of quiet targets in forward

Acoustic modelling and simulation of next generation torpedoes.

NARCIS (Netherlands)

Schippers, P.; Benders, F.P.A.

2003-01-01

Since 1987 sonar performance modelling is developed at TNO Physics and Electronics Laboratory. This is based on propagation modelling in a given environment together with modelling of the sonar based on its specific parameters. Beam forming, pulse type and signal processing are taken into account.

Verifying optimal depth settings for LFAS

NARCIS (Netherlands)

Lam, F.P.A.; Beerens, S.P.; Ainslie, M.A.

2006-01-01

Naval operations in coastal waters are challenging the modelling support in several disciplines. An important instrument for undersea defence in the littoral is the LFAS sonar. To adapt to the local acoustic environment, LFAS sonars can adjust their operation depth to increase the coverage of the

Instantiating a Global Network Measurement Framework

Energy Technology Data Exchange (ETDEWEB)

Tierney, Brian L.; Boote, Jeff; Boyd, Eric; Brown, Aaron; Grigoriev, Maxim; Metzger, Joe; Swany, Martin; Zekauskas, Matt; Zurawski, Jason

2008-12-15

perfSONAR is a web services-based infrastructure for collecting and publishing network performance monitoring. A primary goal of perfSONAR is making it easier to solve end-to-end performance problems on paths crossing several networks. It contains a set of services delivering performance measurements in a federated environment. These services act as an intermediate layer, between the performance measurement tools and the diagnostic or visualization applications. This layer is aimed at making and exchanging performance measurements across multiple networks and multiple user communities, using well-defined protocols. This paper summarizes the key perfSONAR components, and describes how they are deployed by the US-LHC community to monitor the networks distributing LHC data from CERN. All monitoring data described herein is publicly available, and we hope the availability of this data via a standard schema will inspire others to contribute to the effort by building network data analysis applications that use perfSONAR.

Bathymetry and acoustic backscatter data collected in 2010 from Cat Island, Mississippi

Science.gov (United States)

Buster, Noreen A.; Pfeiffer, William R.; Miselis, Jennifer L.; Kindinger, Jack G.; Wiese, Dana S.; Reynolds, B.J.

2012-01-01

Scientists from the U.S. Geological Survey (USGS), St. Petersburg Coastal and Marine Science Center (SPCMSC), in collaboration with the U.S. Army Corps of Engineers (USACE), conducted geophysical and sedimentological surveys around Cat Island, the westernmost island in the Mississippi-Alabama barrier island chain (fig. 1). The objectives of the study were to understand the geologic evolution of Cat Island relative to other barrier islands in the northern Gulf of Mexico and to identify relationships between the geologic history, present day morphology, and sediment distribution. This report contains data from the bathymetry and side-scan sonar portion of the study collected during two geophysical cruises. Interferometric swath bathymetry and side-scan sonar data were collected aboard the RV G.K. Gilbert September 7-15, 2010. Single-beam bathymetry was collected in shallow water around the island (Field Activity Collection System (FACS) logs, and formal Federal Geographic Data Committee (FDGC) metadata.

Actuators, transducers and motors based on giant magnetostrictive materials

Energy Technology Data Exchange (ETDEWEB)

Claeyssen, F.; Lhermet, N.; Le Letty, R. [Cedrat Recherche, Meylan (France); Bouchilloux, P. [Magsoft Corporation, 1223 People`s Avenue, New York 12180 (United States)

1997-08-01

Rare earth-iron magnetostrictive alloys, especially Terfenol-D, feature ``giant`` magnetostrains: static strains of 1000-2000 ppm and dynamic strains of 3500 ppm are reported. These strains permit building various actuating devices (actuators, transducers, motors) both at macro and micro scale. The object of the paper is to recall adapted design methods, especially finite element methods such as ATILA, and to review these different kinds of devices studied at Cedrat Recherche, providing both up-dated experimental and numerical results. The presented devices will include several large displacement longitudinal and shear actuators biased using permanent magnets and used either as characterisation devices or as electromechanical actuators (for active damping, for sonar transducers..), a 1 kHz 4 kW Tonpilz-type sonar transducer called the tripode, a 2 N m torque rotating multi-mode motor, a torsion based drift free micro actuator and a wireless linear micromotor. (orig.)

Body imaging: Diagnosis

African Journals Online (AJOL)

Pfannenstiel incision for caesarean section was noted. No synchronous lesions were identified. Based on the location of the lesion, sonar features and MRI enhancement pattern, the principal radiological diagnosis was that of a desmoid tumour of the left rectus muscle. In fact, the initial sonar-guided core biopsy specimen ...

Experiments with a Ship-Mounted Low Frequency SAS for the Detection of Buried Objects

NARCIS (Netherlands)

Colin, M.E.G.D.; Quesson, B.A.J.; Hetet, A.; Groen, J.; Sabel, J.C.; Zerr, B.; Brusieux, M.; Legris, M.

2004-01-01

In September 2002, GESMA and TNO-FEL carried out a sea trial with a low frequency (20 kHz) sonar mounted on a mine hunter. The objective of the experiments was to collect sonar echoes from proud and buried objects for subsequent synthetic aperture processing. A large data set was collected,

The Feasibility of Generalized Acoustic Sensor Operator Training. Final Report for Period February 1974-February 1975.

Science.gov (United States)

Daniels, Richard W.; Alden, David G.

The feasibility of generalized approaches to training military personnel in the use of different types of sonar/acoustic warfare systems was explored. The initial phase of the project consisted of the analysis of representative sonar and acoustic equipment to identify training areas and operator performance requirements that could be subjected to…

Impact of the marketing activities related to service offer an the Nuclear Information Center of the brazilian National Nuclear Energy Commission

International Nuclear Information System (INIS)

Amaral, Sueli Angelica do

1998-01-01

Exploratory field research confirms the marketing administration philosophy in Nuclear Information Center (CIN) of National Commission of Nuclear Energy (CNEN), analyzing marketing activities referring to SONAR-INIS (current awareness) and SERVIR-INIS (provision of copies) promotion, in order to evaluate the impact of these activities relating to the use of the services by real users. The data collecting took place using a technique of documental analysis, semi-structured interviews with five managers of the Center, simple no-participant observation accomplished by the researcher in CIN, questionnaires about the administration philosophy applied to the managers, and questionnaires sent by mail to 176 users of the international sample. The 122 users'answers (69,31% of answers rate) were analyzed according to the statistical procedures of Statistical Package of Social Sciences (SPSS), with 0,05% of error margin, and 95% of confidence level. Nine assumptions of research were tested. It was concluded that: the first knowledge of the services was by circulars or letters; SONAR-INIS was not considered as the principal service by its information contents in order to develop professional activities by 60,5% of the users; SERVIR-INIS was considered the main service to access the documents related to the interest of 47,8% of the user; to the majority the most important reason to use both services was the convenience and facilities to access the services; suitability of interest was the most important criterion in order to accomplish the appropriate service; the CIN inquiry frequency to know about users' satisfaction level, their information interests, needs and expectation in order to adapt information offer to demand was irregular and seldom; CIN's concerns about knowing users' critics, complaints and suggestions was recognized by users; the majority of the users was interested in receiving information about the benefits of the services; the price of the copies obtained in

Development of an inverse distance weighted active infrared stealth scheme using the repulsive particle swarm optimization algorithm.

Science.gov (United States)

Han, Kuk-Il; Kim, Do-Hwi; Choi, Jun-Hyuk; Kim, Tae-Kuk

2018-04-20

Treatments for detection by infrared (IR) signals are higher than for other signals such as radar or sonar because an object detected by the IR sensor cannot easily recognize its detection status. Recently, research for actively reducing IR signal has been conducted to control the IR signal by adjusting the surface temperature of the object. In this paper, we propose an active IR stealth algorithm to synchronize IR signals from the object and the background around the object. The proposed method includes the repulsive particle swarm optimization statistical optimization algorithm to estimate the IR stealth surface temperature, which will result in a synchronization between the IR signals from the object and the surrounding background by setting the inverse distance weighted contrast radiant intensity (CRI) equal to zero. We tested the IR stealth performance in mid wavelength infrared (MWIR) and long wavelength infrared (LWIR) bands for a test plate located at three different positions on a forest scene to verify the proposed method. Our results show that the inverse distance weighted active IR stealth technique proposed in this study is proved to be an effective method for reducing the contrast radiant intensity between the object and background up to 32% as compared to the previous method using the CRI determined as the simple signal difference between the object and the background.

Introduction to sensors for ranging and imaging

CERN Document Server

Brooker, Graham

2009-01-01

""This comprehensive text-reference provides a solid background in active sensing technology. It is concerned with active sensing, starting with the basics of time-of-flight sensors (operational principles, components), and going through the derivation of the radar range equation and the detection of echo signals, both fundamental to the understanding of radar, sonar and lidar imaging. Several chapters cover signal propagation of both electromagnetic and acoustic energy, target characteristics, stealth, and clutter. The remainder of the book introduces the range measurement process, active ima

Summary of Research 1993

Science.gov (United States)

1993-12-31

TrOLOGY hRi: Sensors. Pfeifer, G.K., Frack , K.L., and Kjono, 0., wSunmary Report on Sonar KMEWODMMS Passive Sonar, Ana Signal Modeling for FY1993 (U), UPS...bilateral force feedback in hydraulic tolooperator systems is investigatod. In this work, single and two DOF systems have been constructed and tested

The marine activities performed within the TOMO-ETNA experiment

Directory of Open Access Journals (Sweden)

Mauro Coltelli

2016-09-01

Full Text Available The TOMO-ETNA experiment was planned in order to obtain a detailed geological and structural model of the continental and oceanic crust beneath Mt. Etna volcano and northeastern Sicily up to the Aeolian Islands (southern Italy, by integrating data from active and passive refraction and reflection seismic methodologies, magnetic and gravity surveys. This paper focuses on the marine activities performed within the experiment, which have been carried out in the Ionian and Tyrrhenian Seas, during three multidisciplinary oceanographic cruises, involving three research vessels (“Sarmiento de Gamboa”, “Galatea” and “Aegaeo” belonging to different countries and institutions. During the offshore surveys about 9700 air-gun shots were produced to achieve a high-resolution seismic tomography through the wide-angle seismic refraction method, covering a total of nearly 2650 km of shooting tracks. To register ground motion, 27 ocean bottom seismometers were deployed, extending the inland seismic permanent network of the Istituto Nazionale di Geofisica e Vulcanologia and a temporary network installed for the experiment. A total of 1410 km of multi-channel seismic reflection profiles were acquired to image the subsurface of the area and to achieve a 2D velocity model for each profile. Multibeam sonar and sub bottom profiler data were also collected. Moreover, a total of 2020 km of magnetic and 680 km of gravity track lines were acquired to compile magnetic and gravity anomaly maps offshore Mt. Etna volcano. Here, high-resolution images of the seafloor, as well as sediment and rock samples, were also collected using a remotely operated vehicle.

Autonomous Navigation for Autonomous Underwater Vehicles Based on Information Filters and Active Sensing

Directory of Open Access Journals (Sweden)

Tianhong Yan

2011-11-01

Full Text Available This paper addresses an autonomous navigation method for the autonomous underwater vehicle (AUV C-Ranger applying information-filter-based simultaneous localization and mapping (SLAM, and its sea trial experiments in Tuandao Bay (Shangdong Province, P.R. China. Weak links in the information matrix in an extended information filter (EIF can be pruned to achieve an efficient approach-sparse EIF algorithm (SEIF-SLAM. All the basic update formulae can be implemented in constant time irrespective of the size of the map; hence the computational complexity is significantly reduced. The mechanical scanning imaging sonar is chosen as the active sensing device for the underwater vehicle, and a compensation method based on feedback of the AUV pose is presented to overcome distortion of the acoustic images due to the vehicle motion. In order to verify the feasibility of the navigation methods proposed for the C-Ranger, a sea trial was conducted in Tuandao Bay. Experimental results and analysis show that the proposed navigation approach based on SEIF-SLAM improves the accuracy of the navigation compared with conventional method; moreover the algorithm has a low computational cost when compared with EKF-SLAM.

Autonomous navigation for autonomous underwater vehicles based on information filters and active sensing.

Science.gov (United States)

He, Bo; Zhang, Hongjin; Li, Chao; Zhang, Shujing; Liang, Yan; Yan, Tianhong

2011-01-01

This paper addresses an autonomous navigation method for the autonomous underwater vehicle (AUV) C-Ranger applying information-filter-based simultaneous localization and mapping (SLAM), and its sea trial experiments in Tuandao Bay (Shangdong Province, P.R. China). Weak links in the information matrix in an extended information filter (EIF) can be pruned to achieve an efficient approach-sparse EIF algorithm (SEIF-SLAM). All the basic update formulae can be implemented in constant time irrespective of the size of the map; hence the computational complexity is significantly reduced. The mechanical scanning imaging sonar is chosen as the active sensing device for the underwater vehicle, and a compensation method based on feedback of the AUV pose is presented to overcome distortion of the acoustic images due to the vehicle motion. In order to verify the feasibility of the navigation methods proposed for the C-Ranger, a sea trial was conducted in Tuandao Bay. Experimental results and analysis show that the proposed navigation approach based on SEIF-SLAM improves the accuracy of the navigation compared with conventional method; moreover the algorithm has a low computational cost when compared with EKF-SLAM.

Dredging in Sediments Containing Munitions and Explosives of Concern (MEC)

Science.gov (United States)

2008-08-01

UXO diver tech- niques to recover the targets. First, the diver using a fluxgate magnetometer attempted to verify the exist- ence of a target...MEC. These technologies included: 1. Synthetic Aperture SONAR. 2. Magnetometers and electromagnetic induction sensors. 3. Magnetometer /SONAR...4. Differential Magnetometer . 5. Mobile Underwater Debris Survey System. The feasibility of site characterization of the borrow area

Robust Target Tracking with Multi-Static Sensors under Insufficient TDOA Information.

Science.gov (United States)

Shin, Hyunhak; Ku, Bonhwa; Nelson, Jill K; Ko, Hanseok

2018-05-08

This paper focuses on underwater target tracking based on a multi-static sonar network composed of passive sonobuoys and an active ping. In the multi-static sonar network, the location of the target can be estimated using TDOA (Time Difference of Arrival) measurements. However, since the sensor network may obtain insufficient and inaccurate TDOA measurements due to ambient noise and other harsh underwater conditions, target tracking performance can be significantly degraded. We propose a robust target tracking algorithm designed to operate in such a scenario. First, track management with track splitting is applied to reduce performance degradation caused by insufficient measurements. Second, a target location is estimated by a fusion of multiple TDOA measurements using a Gaussian Mixture Model (GMM). In addition, the target trajectory is refined by conducting a stack-based data association method based on multiple-frames measurements in order to more accurately estimate target trajectory. The effectiveness of the proposed method is verified through simulations.

Detection of active hydrothermal vent fields in the Pescadero Basin and on the Alarcon Rise using AUV multibeam and CTD data

Science.gov (United States)

Caress, D. W.; Troni, G.; Clague, D. A.; Paduan, J. B.; Martin, J. F.; Thomas, H. J.; Thompson, D.; Conlin, D.; Martin, E. J.; meneses-Quiroz, E.; Nieves-Cardoso, C.; Angel Santa Rosa del Rio, M.

2015-12-01

The MBARI AUV D. Allan B. collected high resolution bathymetry, sidescan, and subbottom profiles along the neovolcanic zone of the Alarcon Rise and across the southern Pescadero Basin during 2012 and 2015 MBARI expeditions to the Gulf of California (GOC). The combination of high resolution multibeam bathymetry and seawater temperature data has proven effective in identifying active high temperature vent fields, as validated by inspection and sampling during ROV dives. The AUV carries a 200 kHz multibeam sonar, 110 kHz chirp sidescan sonar, a 1-6 kHz chirp subbottom profiler, and a conductivity, temperature and depth (CTD) sensor for ~17-hour duration missions. Flying at 5.4 km/hr at 50 m altitude, the processed AUV bathymetry has a 0.1 m vertical precision and a 1 m lateral resolution. Chimneys taller than 1.5 m are sufficiently distinctive to allow provisional identification. The CTD temperature data have a nominal 0.002°C accuracy. Following calculation of potential temperature and correcting for average local variation of potential temperature with depth, anomalies greater than 0.05 °C can be reliably identified using a spike detection filter. MBARI AUV mapping surveys are typically planned using a 150 m survey line spacing, so the CTD data may be collected as much as 75 m away from any vent plume source. Five active high temperature vent fields were discovered in the southern GOC, with the Auka Field in the southern Pescadero Basin, and the Ja Sít, Pericú, Meyibó, and Tzab-ek Fields along the Alarcon Rise. In all five cases, hydrothermal vent chimneys are readily identifiable in the multibeam bathymetry, and temperature anomalies are observed above background variability. Other apparent hydrothermal chimneys were observed in the bathmetry that did not exhibit water temperature anomalies; most of these were visited during ROV dives and confirmed to be inactive sites. The maximum water column anomalies are 0.13°C observed above the Meyibó field and 0.25�

Use of Dual Frequency Identification Sonar to Determine Adult Chinook Salmon (Oncorhynchus tshawytscha) Escapement in the Secesh River, Idaho ; Annual Report, January 2008 – December 2008.

Energy Technology Data Exchange (ETDEWEB)

Kucera, Paul A. [Nez Perce Tribe Department of Fisheries Resources Management

2009-06-26

Chinook salmon in the Snake River basin were listed as threatened under the Endangered Species Act in 1992 (NMFS 1992). The Secesh River represents the only stream in the Snake River basin where natural origin (wild) salmon escapement monitoring occurs at the population level, absent a supplementation program. As such the Secesh River has been identified as a long term salmon escapement and productivity monitoring site by the Nez Perce Tribe Department of Fisheries Resources Management. Salmon managers will use this data for effective population management and evaluation of the effect of conservation actions on a natural origin salmon population. The Secesh River also acts as a reference stream for supplementation program comparison. Dual frequency identification sonar (DIDSON) was used to determine adult spring and summer Chinook salmon escapement in the Secesh River in 2008. DIDSON technology was selected because it provided a non-invasive method for escapement monitoring that avoided listed species trapping and handling incidental mortality, and fish impedance related concerns. The DIDSON monitoring site was operated continuously from June 13 to September 14. The first salmon passage was observed on July 3. DIDSON site total estimated salmon escapement, natural and hatchery fish, was 888 fish {+-} 65 fish (95% confidence interval). Coefficient of variation associated with the escapement estimate was 3.7%. The DIDSON unit was operational 98.1% of the salmon migration period. Adult salmon migration timing in the Secesh River occurred over 74 days from July 3 to September 14, with 5,262 total fish passages observed. The spawning migration had 10%, median, and 90% passage dates of July 8, July 16, and August 12, respectively. The maximum number of net upstream migrating salmon was above the DIDSON monitoring site on August 27. Validation monitoring of DIDSON target counts with underwater optical cameras occurred for species identification. A total of 860 optical

MBARI Mapping AUV: A High-Resolution Deep Ocean Seafloor Mapping Capability

Science.gov (United States)

Caress, D. W.; Kirkwood, W. J.; Thomas, H.; McEwen, R.; Henthorn, R.; McGill, P.; Thompson, D.; Sibenac, M.; Jensen, S.; Shane, F.; Hamilton, A.

2005-05-01

The Monterey Bay Aquarium Research Institute (MBARI) is developing an autonomous seafloor mapping capability for deep ocean science applications. The MBARI Mapping AUV is a 0.53 m (21 in) diameter, 5.1 m (16.7 ft) long, Dorado-class vehicle designed to carry four mapping sonars. The primary sensor is a 200 kHz multibeam sonar producing swath bathymetry and sidescan. In addition, the vehicle carries 100 kHz and 410 kHz chirp sidescan sonars, and a 2-16 kHz sweep chirp subbottom profiler. Navigation and attitude data are obtained from an inertial navigation system (INS) incorporating a ring laser gyro and a 300 kHz Doppler velocity log (DVL). The vehicle also includes acoustic modem, ultra-short baseline navigation, and long-baseline navigation systems. The Mapping AUV is powered by 6 kWhr of Li-polymer batteries, providing expected mission duration of 12 hours at a typical speed of 1.5 m/s. All components of the vehicle are rated to 6000 m depth, allowing MBARI to conduct high-resolution mapping of the deep-ocean seafloor. The sonar package is also be mountable on ROV Ventana, allowing surveys at altitudes less than 20 m at topographically challenging sites. The vehicle was assembled and extensively tested during 2004; this year we are commencing operations for MBARI science projects while continuing the process of testing and integrating the complete suite of sensors and systems. MBARI is beginning to use this capability to observe the changing morphology of dynamic systems such as submarine canyons and active slumps, to map deep-water benthic habitats at resolutions comparable to ROV and submersible observations, to provide basemaps for ROV dives, and to provide high resolution bathymetry and subbottom profiles as part of a variety of projects requiring knowledge of the seafloor. We will present initial results from surveys in and around Monterey Canyon, including high resolution repeat surveys of four sites along the canyon axis.

Active Listening in a Bat Cocktail Party: Adaptive Echolocation and Flight Behaviors of Big Brown Bats, Eptesicus fuscus, Foraging in a Cluttered Acoustic Environment.

Science.gov (United States)

Warnecke, Michaela; Chiu, Chen; Engelberg, Jonathan; Moss, Cynthia F

2015-09-01

In their natural environment, big brown bats forage for small insects in open spaces, as well as in vegetation and in the presence of acoustic clutter. While searching and hunting for prey, bats experience sonar interference, not only from densely cluttered environments, but also from calls of conspecifics foraging in close proximity. Previous work has shown that when two bats compete for a single prey item in a relatively open environment, one of the bats may go silent for extended periods of time, which can serve to minimize sonar interference between conspecifics. Additionally, pairs of big brown bats have been shown to adjust frequency characteristics of their vocalizations to avoid acoustic interference in echo processing. In this study, we extended previous work by examining how the presence of conspecifics and environmental clutter influence the bat's echolocation behavior. By recording multichannel audio and video data of bats engaged in insect capture in open and cluttered spaces, we quantified the bats' vocal and flight behaviors. Big brown bats flew individually and in pairs in an open and cluttered room, and the results of this study shed light on the different strategies that this species employs to negotiate a complex and dynamic environment. © 2015 S. Karger AG, Basel.

Sampling Approaches for Multi-Domain Internet Performance Measurement Infrastructures

Energy Technology Data Exchange (ETDEWEB)

Calyam, Prasad

2014-09-15

The next-generation of high-performance networks being developed in DOE communities are critical for supporting current and emerging data-intensive science applications. The goal of this project is to investigate multi-domain network status sampling techniques and tools to measure/analyze performance, and thereby provide “network awareness” to end-users and network operators in DOE communities. We leverage the infrastructure and datasets available through perfSONAR, which is a multi-domain measurement framework that has been widely deployed in high-performance computing and networking communities; the DOE community is a core developer and the largest adopter of perfSONAR. Our investigations include development of semantic scheduling algorithms, measurement federation policies, and tools to sample multi-domain and multi-layer network status within perfSONAR deployments. We validate our algorithms and policies with end-to-end measurement analysis tools for various monitoring objectives such as network weather forecasting, anomaly detection, and fault-diagnosis. In addition, we develop a multi-domain architecture for an enterprise-specific perfSONAR deployment that can implement monitoring-objective based sampling and that adheres to any domain-specific measurement policies.

Arsenic, cadmium, chromium, lead, manganese, mercury, and selenium in feathers of Black-legged Kittiwake (Rissa tridactyla) and Black Oystercatcher (Haematopus bachmani) from Prince William Sound, Alaska

Energy Technology Data Exchange (ETDEWEB)

Burger, Joanna [Division of Life Sciences, Rutgers University, 604 Allison Road, Piscataway, New Jersey 08854-8082 (United States); Consortium for Risk Evaluation with Stakeholder Participation (CRESP), Piscataway, New Jersey 08854 (United States); Environmental and Occupational Health Sciences Institute (EOHSI), Piscataway, New Jersey 08854 (United States)], E-mail: burger@biology.rutgers.edu; Gochfeld, Michael [Consortium for Risk Evaluation with Stakeholder Participation (CRESP), Piscataway, New Jersey 08854 (United States); Environmental and Occupational Health Sciences Institute (EOHSI), Piscataway, New Jersey 08854 (United States); Environmental and Occupational Medicine, UMDNJ-Robert Wood Johnson Medical School, Piscataway, New Jersey 08854 (United States); Sullivan, Kelsey [U.S. Fish and Wildlife Service, 1011 East Tudor Road, Anchorage, Alaska 99503 (United States); P.O. Box 801, Bethel, Maine, 04217 (United States); Irons, David [U.S. Fish and Wildlife Service, 1011 East Tudor Road, Anchorage, Alaska 99503 (United States); McKnight, Aly [P.O. Box 801, Bethel, Maine, 04217 (United States)

2008-07-15

Arsenic, cadmium, chromium, lead, manganese, mercury and selenium were analyzed in the feathers of Black-legged Kittiwakes (Rissa tridactyla) from Shoup Bay in Prince William Sound, Alaska to determine if there were age-related differences in metal levels, and in Black Oystercatchers (Haematopus bachmani)) from the same region to determine if there were differences in oiled and unoiled birds. Except for mercury, there were no age-related differences in metals levels in the feathers of kittiwakes. Kittiwakes over 13 years of age had the highest levels of mercury. There were no differences in levels of metals in the feathers of oystercatchers from oiled and unoiled regions of Prince William Sound. Except for mercury, the feathers of oystercatchers had significantly higher levels of all metals than those of kittiwakes. Levels of mercury in kittiwake feathers (mean of 2910 ng/g [ppb]) were within the range of many species of seabirds reported for other studies, and were generally below adverse effects levels.

Active control of acoustic field-of-view in a biosonar system.

Directory of Open Access Journals (Sweden)

Yossi Yovel

2011-09-01

Full Text Available Active-sensing systems abound in nature, but little is known about systematic strategies that are used by these systems to scan the environment. Here, we addressed this question by studying echolocating bats, animals that have the ability to point their biosonar beam to a confined region of space. We trained Egyptian fruit bats to land on a target, under conditions of varying levels of environmental complexity, and measured their echolocation and flight behavior. The bats modulated the intensity of their biosonar emissions, and the spatial region they sampled, in a task-dependant manner. We report here that Egyptian fruit bats selectively change the emission intensity and the angle between the beam axes of sequentially emitted clicks, according to the distance to the target, and depending on the level of environmental complexity. In so doing, they effectively adjusted the spatial sector sampled by a pair of clicks-the "field-of-view." We suggest that the exact point within the beam that is directed towards an object (e.g., the beam's peak, maximal slope, etc. is influenced by three competing task demands: detection, localization, and angular scanning-where the third factor is modulated by field-of-view. Our results suggest that lingual echolocation (based on tongue clicks is in fact much more sophisticated than previously believed. They also reveal a new parameter under active control in animal sonar-the angle between consecutive beams. Our findings suggest that acoustic scanning of space by mammals is highly flexible and modulated much more selectively than previously recognized.

Composite Wavelet Filters for Enhanced Automated Target Recognition

Science.gov (United States)

Chiang, Jeffrey N.; Zhang, Yuhan; Lu, Thomas T.; Chao, Tien-Hsin

2012-01-01

Automated Target Recognition (ATR) systems aim to automate target detection, recognition, and tracking. The current project applies a JPL ATR system to low-resolution sonar and camera videos taken from unmanned vehicles. These sonar images are inherently noisy and difficult to interpret, and pictures taken underwater are unreliable due to murkiness and inconsistent lighting. The ATR system breaks target recognition into three stages: 1) Videos of both sonar and camera footage are broken into frames and preprocessed to enhance images and detect Regions of Interest (ROIs). 2) Features are extracted from these ROIs in preparation for classification. 3) ROIs are classified as true or false positives using a standard Neural Network based on the extracted features. Several preprocessing, feature extraction, and training methods are tested and discussed in this paper.

Multi-sourced, 3D geometric characterization of volcanogenic karst features: Integrating lidar, sonar, and geophysical datasets (Invited)

Science.gov (United States)

Sharp, J. M.; Gary, M. O.; Reyes, R.; Halihan, T.; Fairfield, N.; Stone, W. C.

2009-12-01

Karstic aquifers can form very complex hydrogeological systems and 3-D mapping has been difficult, but Lidar, phased array sonar, and improved earth resistivity techniques show promise in this and in linking metadata to models. Zacatón, perhaps the Earth’s deepest cenote, has a sub-aquatic void space exceeding 7.5 x 106 cubic m3. It is the focus of this study which has created detailed 3D maps of the system. These maps include data from above and beneath the the water table and within the rock matrix to document the extent of the immense karst features and to interpret the geologic processes that formed them. Phase 1 used high resolution (20 mm) Lidar scanning of surficial features of four large cenotes. Scan locations, selected to achieve full feature coverage once registered, were established atop surface benchmarks with UTM coordinates established using GPS and Total Stations. The combined datasets form a geo-registered mesh of surface features down to water level in the cenotes. Phase 2 conducted subsurface imaging using Earth Resistivity Imaging (ERI) geophysics. ERI identified void spaces isolated from open flow conduits. A unique travertine morphology exists in which some cenotes are dry or contain shallow lakes with flat travertine floors; some water-filled cenotes have flat floors without the cone of collapse material; and some have collapse cones. We hypothesize that the floors may have large water-filled voids beneath them. Three separate flat travertine caps were imaged: 1) La Pilita, which is partially open, exposing cap structure over a deep water-filled shaft; 2) Poza Seca, which is dry and vegetated; and 3) Tule, which contains a shallow (<1 m) lake. A fourth line was run adjacent to cenote Verde. La Pilita ERI, verified by SCUBA, documented the existence of large water-filled void zones ERI at Poza Seca showed a thin cap overlying a conductive zone extending to at least 25 m depth beneath the cap with no lower boundary of this zone evident

Sediment dynamics and the burial and exhumation of bedrock reefs along an emergent coastline as elucidated by repetitive sonar surveys: Northern Monterey Bay, CA

Science.gov (United States)

Storlazzi, C.D.; Fregoso, T.A.; Golden, N.E.; Finlayson, D.P.

2011-01-01

Two high-resolution bathymetric and acoustic backscatter sonar surveys were conducted along the energetic emergent inner shelf of northern Monterey Bay, CA, USA, in the fall of 2005 and the spring of 2006 to determine the impact of winter storm waves, beach erosion, and river floods on biologically-important siliclastic bedrock reef habitats. The surveys extended from water depths of 4 m to 22 m and covered an area of 3.14 km2, 45.8% of which was bedrock, gravel, and coarse-grained sand and 54.2% was fine-grained sand. Our analyses of the bathymetric and acoustic backscatter data demonstrates that during the 6 months between surveys, 11.4% of the study area was buried by fine-grained sand while erosion resulted in the exposure of bedrock or coarse-grained sand over 26.5% of the study area. The probability of burial decreased with increasing water depth and rugosity; the probability of exhumation increased with increasing wave-induced near-bed shear stress, seabed slope and rugosity. Much of the detected change was at the boundary between bedrock and unconsolidated sediment due to sedimentation and erosion burying or exhuming bedrock, respectively. In a number of cases, however, the change in seabed character was apparently due to changes in sediment grain size when scour exposed what appeared to be an underlying coarser-grained lag or the burial of coarser-grained sand and gravel by fine-grained sand. These findings suggest that, in some places, (a) burial and exhumation of nearshore bedrock reefs along rocky, energetic inner shelves occurs over seasonal timescales and appears related to intrinsic factors such as seabed morphology and extrinsic factors such as wave forces, and (b) single acoustic surveys typically employed for geologic characterization and/or habitat mapping may not adequately characterize the geomorphologic and sedimentologic nature of these types of environments that typify most of the Pacific Ocean and up to 50% of the world's coastlines.

Neotectonic investigations in Southern Ontario. Prince Edward County - Phase 2

International Nuclear Information System (INIS)

McFall, G.H.; Allam, A.

1991-06-01

This report summarizes the preliminary results of geological and geophysical investigations and offshore side scan sonar surveys of the bedrock and unconsolidated sediments in Prince Edward County, Southern Ontario, by the Ontario Geological Survey in 1989. Investigations were focused on deformations in the bedrock and the surficial deposits. Some of these deformations may be neotectonic in origin. Low magnitude seismicity in the Prince Edward County region appears to be spatially related to a major regional fault system that crosses Lake Ontario and consists of the seismically active Clarendon-Linden Fault System in New York State, the Picton-Napanee and Rideau Faults, the Frontenac-Sharbot Lake Terrane Boundary and the assumed Salmon River Fault in Ontario. Detailed observations were made in the Long Point study area and the Mountain View and Picton Quarries. Bedrock structural features were documented, including: joints; normal, reverse and strike strip faults; brittle folds; and Jurassic age ultramafic dyke. Detailed refraction seismic surveys were conducted across a local fault and possible fold structures. Magnetic surveys, conducted in conjunction with the offshore side scan sonar surveys, documented large magnetic anomalies southeast of Point Petre and at the northeast end of Long Reach. Side scan sonar surveys of the lake bottom to the east of Point Petre confirm the presence of pop-ups in that area of the lake bottom which is immediately adjacent to where pop-ups are observed on land. The pop-ups present in the lake bottom have similar orientations to those mapped in the study area

Sound Use, Sequential Behavior and Ecology of Foraging Bottlenose Dolphins, Tursiops Truncatus

Science.gov (United States)

1999-09-01

Richards, 1992; Nowacek et al, 1995). In addition, we have extensive information about the distribution, anatomy , life history, diet, and general... anatomy of a sonar signal generator. In Animal Sonar: Processes and Performance (ed. P. E. Nachtigall and P. W. B. Moore), pp. 67-77. Plenum Press...Mwanza, N. (1994). Day-journey length and daily diet of solitary male gorillas in lowland and highland habitats. International journal of Primatology

Shallow water acoustic backscatter and reverberation measurements using a 68-kHz cylindrical array: a dissertation

OpenAIRE

Gallaudet, Timothy C. (Timothy Cole), 1967-

2001-01-01

The characterization of high frequency, shallow water acoustic backscatter and reverberation is important because acoustic systems are used in many scientific, commercial, and military applications. The approach taken is to use data collected by the Toroidal Volume Search Sonar (TVSS), a 68 kHz multibeam sonar capable of 360 deg imaging in a vertical plane perpendicular to its direction of travel. With this unique capability, acoustic backscatter imagery of the seafloor, sea surface, and hori...

Introduction to Sonar, Revision.

Science.gov (United States)

1976-01-01

own ship anddesign e andm constructiones ofmmechanicale andthe the target, measured in the deck plane. Thiserni equipntto ovehicol quantity is...attention of your security 6. You may associate with non-citizens on officer or commanding officer. State the facts: a close social basis. However, any...Rank/Rate Designator Social Security Number COURSE COMPLETION Letters of satisfactory completion are issued only to personnel whose courses are

Impact of bathymetric system advances on hydrography

Digital Repository Service at National Institute of Oceanography (India)

Ranade, G.

undergone unprecedented changes with the advancement in the motion sensor technology. By late 1970 gyro stabilized accelerometer based attitude monitoring systems, computing roll, pitch and heave sensing and came in to existence. Doppler sonar principle...). “Multibeam bathymetric sonar: Sea Beam and Hydrochart”, Mar. Geod., vol. 4, pp.77-93. 4. Urick, R. (1975), “Principles of Underwater Acoustics”, McGraw – Hill. 5. Christian de Moustier, C. (1987). “Online Sea Beam acoustic imaging, Proc. Oceans ‘87...

Echolocation call intensity and directionality in flying short-tailed fruit bats, Carollia perspicillata (Phyllostomidae)

DEFF Research Database (Denmark)

Brinkløv, Signe; Jakobsen, Lasse; Ratcliffe, John M

2011-01-01

The directionality of bat echolocation calls defines the width of bats' sonar "view," while call intensity directly influences detection range since adequate sound energy must impinge upon objects to return audible echoes. Both are thus crucial parameters for understanding biosonar signal design....... a longer and narrower sonar range than previously thought. C. perspicillata orient and forage in the forest interior and the narrow beam might be adaptive in clutter, by reducing the number and intensity of off-axis echoes....

CHIRP-Like Signals: Estimation, Detection and Processing A Sequential Model-Based Approach

Energy Technology Data Exchange (ETDEWEB)

Candy, J. V. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

2016-08-04

Chirp signals have evolved primarily from radar/sonar signal processing applications specifically attempting to estimate the location of a target in surveillance/tracking volume. The chirp, which is essentially a sinusoidal signal whose phase changes instantaneously at each time sample, has an interesting property in that its correlation approximates an impulse function. It is well-known that a matched-filter detector in radar/sonar estimates the target range by cross-correlating a replicant of the transmitted chirp with the measurement data reflected from the target back to the radar/sonar receiver yielding a maximum peak corresponding to the echo time and therefore enabling the desired range estimate. In this application, we perform the same operation as a radar or sonar system, that is, we transmit a “chirp-like pulse” into the target medium and attempt to first detect its presence and second estimate its location or range. Our problem is complicated by the presence of disturbance signals from surrounding broadcast stations as well as extraneous sources of interference in our frequency bands and of course the ever present random noise from instrumentation. First, we discuss the chirp signal itself and illustrate its inherent properties and then develop a model-based processing scheme enabling both the detection and estimation of the signal from noisy measurement data.

LIDAR and atmosphere remote sensing [DST Space Science Initiatives

CSIR Research Space (South Africa)

Venkataraman, S

2009-04-01

Full Text Available Energy Source included in the measurement. Slide 2 © CSIR 2008 www.csir.co.za The observer can control the source Eg. Radar, Lidar, Sodar, Sonar etc. (b) Passive remote sensors. Energy source is not included in the measurement... Instrument Passive Slide 3 © CSIR 2008 www.csir.co.za Active LiDAR Principle • LIDAR (Light Detection and Ranging) • LiDAR employs a laser as a source of pulsed energy • Lasers are advantageous because – checkbld Monochromatic...

Measurement of the acoustic reflectivity of sirenia (Florida manatees) at 171 kHz.

Science.gov (United States)

Jaffe, Jules S; Simonet, Fernando; Roberts, Paul L D; Bowles, Ann E

2007-01-01

The Florida manatee (Trichechus manatus latirostris) is an endangered sirenian. At present, its adult population (approximately 2200) seems stable, but tenuous. Manatee-boat collisions are a significant proportion (approximately 25%) of mortalities. Here, the potential use of active sonar for detecting manatees by quantifying sonic reflectivity is explored. In order to estimate reflectivity two methods were used. One method measured live reflections from captive animals using a carefully calibrated acoustic and co-registered optical system. The other method consisted of the analysis of animal tissue in order to obtain estimates of the sound speed and density and to predict reflectivity. The impedance measurement predicts that for a lateral view, the tissue reflectivity is close to 0.13, with a critical grazing angle of 28 degrees. Data measured from live animals indicate that substantial reflections can be recorded, however in many instances observed "empirical target strengths" were less than an experimentally dependent -48-dB threshold. Conclusions favor the hypothesis that the animals reflect substantial amounts of sound; however, the reflections can often be specular, and therefore impractical for observation by a manatee detection sonar operating at 171 kHz.

Submarine glacial landforms on the Bay of Fundy–northern Gulf of Maine continental shelf

Science.gov (United States)

Todd, B.J.; Shaw, J.; Valentine, Page C.

2016-01-01

The Bay of Fundy–northern Gulf of Maine region surrounds the southern part of Nova Scotia, encompassing, from west to east, the Bay of Fundy, Grand Manan Basin, German Bank, Browns Bank, Northeast Channel and northeastern Georges Bank (Fig. 1a, b). During the last glacial maximum (c. 24–20 14C ka BP), the SE margin of the Laurentide Ice Sheet (LIS) occupied the study area, the rest of the Gulf of Maine and the continental Scotian Shelf off Atlantic Canada (see Dyke et al. 2002, fig. 1; Shaw et al. 2006, fig. 8; Hundert & Piper 2008, fig. 16). Early mapping of the glaciated region on the Scotian Shelf using side-scan sonar imagery and seismic-reflection profiles revealed topographic features interpreted to be recessional moraines indicative of retreat of the LIS (King et al. 1972; King 1996). Subsequently, multibeam sonar seafloor mapping of local-scale glacial landforms on the inner Scotian Shelf off Halifax, Nova Scotia (Fig. 1b) provided further information on the dynamics of the advance and retreat of the ice sheet (Loncarevic et al.1994). Interpretation of seismic-reflection profiles across Georges Bank revealed that the surficial sediment is a veneer of glacial debris transported to Georges Bank by the LIS during the late Pleistocene from continental areas to the north (Shepard et al. 1934; Knott & Hoskins 1968; Schlee 1973; Twichell et al. 1987; Fader et al. 1988). Recent high-resolution multibeam sonar surveys of German Bank and the Bay of Fundy mapped a complex of ice-advance and ice-retreat features attributed to the activity of the LIS (Todd et al. 2007; Todd & Shaw 2012).

Morphodynamic Impacts of Hurricane Sandy on the Inner-shelf (Invited)

Science.gov (United States)

Trembanis, A. C.; Beaudoin, J. D.; DuVal, C.; Schmidt, V. E.; Mayer, L. A.

2013-12-01

Through the careful execution of precision high-resolution acoustic sonar surveys over the period of October 2012 through July 2013, we have obtained a unique set of high-resolution before and after storm measurements of seabed morphology and in situ hydrodynamic conditions (waves and currents) capturing the impact of the storm at an inner continental shelf field site known as the 'Redbird reef' (Raineault et al., 2013). Understanding the signature of this storm event is important for identifying the impacts of such events and for understanding the role that such events have in the transport of sediment and marine debris on the inner continental shelf. In order to understand and characterize the ripple dynamics and scour processes in an energetic, heterogeneous inner-shelf setting, a series of high-resolution geoacoustic surveys were conducted before and after Hurricane Sandy. Our overall goal is to improve our understanding of bedform dynamics and spatio-temporal length scales and defect densities through the application of a recently developed fingerprint algorithm technique (Skarke and Trembanis, 2011). Utilizing high-resolution swath sonar collected by an AUV and from surface vessel multibeam sonar, our study focuses both on bedforms in the vicinity of manmade seabed objects (e.g. shipwrecks and subway cars) and dynamic natural ripples on the inner-shelf in energetic coastal settings with application to critical military operations such as mine countermeasures. Seafloor mapping surveys were conducted both with a ship-mounted multibeam echosounder (200 kHz and 400 kHz) and an Autonomous Underwater Vehicle (AUV) configured with high-resolution side-scan sonar (900 and 1800 kHz) and a phase measuring bathymetric sonar (500 kHz). These geoacoustic surveys were further augmented with data collected by in situ instruments placed on the seabed that recorded measurements of waves and currents at the site before, during, and after the storm. Multibeam echosounder map of

Impact of the marketing activities related to service offer an the Nuclear Information Center of the brazilian National Nuclear Energy Commission; Impacto das atividades de marketing relativas a promocao de servicos no Centro de Informacoes Nucleares da Comissao Nacional de Energia Nuclear

Energy Technology Data Exchange (ETDEWEB)

Amaral, Sueli Angelica do

1998-12-31

Exploratory field research confirms the marketing administration philosophy in Nuclear Information Center (CIN) of National Commission of Nuclear Energy (CNEN), analyzing marketing activities referring to SONAR-INIS (current awareness) and SERVIR-INIS (provision of copies) promotion, in order to evaluate the impact of these activities relating to the use of the services by real users. The data collecting took place using a technique of documental analysis, semi-structured interviews with five managers of the Center, simple no-participant observation accomplished by the researcher in CIN, questionnaires about the administration philosophy applied to the managers, and questionnaires sent by mail to 176 users of the international sample. The 122 users`answers (69,31% of answers rate) were analyzed according to the statistical procedures of Statistical Package of Social Sciences (SPSS), with 0,05% of error margin, and 95% of confidence level. Nine assumptions of research were tested. It was concluded that: the first knowledge of the services was by circulars or letters; SONAR-INIS was not considered as the principal service by its information contents in order to develop professional activities by 60,5% of the users; SERVIR-INIS was considered the main service to access the documents related to the interest of 47,8% of the user; to the majority the most important reason to use both services was the convenience and facilities to access the services; suitability of interest was the most important criterion in order to accomplish the appropriate service; the CIN inquiry frequency to know about users` satisfaction level, their information interests, needs and expectation in order to adapt information offer to demand was irregular and seldom; CIN`s concerns about knowing users` critics, complaints and suggestions was recognized by users; the majority of the users was interested in receiving information about the benefits of the services; the price of the copies obtained in

Impact of the marketing activities related to service offer an the Nuclear Information Center of the brazilian National Nuclear Energy Commission; Impacto das atividades de marketing relativas a promocao de servicos no Centro de Informacoes Nucleares da Comissao Nacional de Energia Nuclear

Energy Technology Data Exchange (ETDEWEB)

Amaral, Sueli Angelica do

1999-12-31

Exploratory field research confirms the marketing administration philosophy in Nuclear Information Center (CIN) of National Commission of Nuclear Energy (CNEN), analyzing marketing activities referring to SONAR-INIS (current awareness) and SERVIR-INIS (provision of copies) promotion, in order to evaluate the impact of these activities relating to the use of the services by real users. The data collecting took place using a technique of documental analysis, semi-structured interviews with five managers of the Center, simple no-participant observation accomplished by the researcher in CIN, questionnaires about the administration philosophy applied to the managers, and questionnaires sent by mail to 176 users of the international sample. The 122 users`answers (69,31% of answers rate) were analyzed according to the statistical procedures of Statistical Package of Social Sciences (SPSS), with 0,05% of error margin, and 95% of confidence level. Nine assumptions of research were tested. It was concluded that: the first knowledge of the services was by circulars or letters; SONAR-INIS was not considered as the principal service by its information contents in order to develop professional activities by 60,5% of the users; SERVIR-INIS was considered the main service to access the documents related to the interest of 47,8% of the user; to the majority the most important reason to use both services was the convenience and facilities to access the services; suitability of interest was the most important criterion in order to accomplish the appropriate service; the CIN inquiry frequency to know about users` satisfaction level, their information interests, needs and expectation in order to adapt information offer to demand was irregular and seldom; CIN`s concerns about knowing users` critics, complaints and suggestions was recognized by users; the majority of the users was interested in receiving information about the benefits of the services; the price of the copies obtained in

High-frequency acoustic imaging of L Lake Phase 4 [Savannah River Site, South Carolina

International Nuclear Information System (INIS)

Dunn, D.L.; Sjostrom, Keith J.; Leist, Rodney L.; Harmon, Thomas S. Jr.

1997-01-01

The objective of the seismic reflection and side scan sonar survey is to determine the location, aerial extent, and depth of burial pits situated along the reservoir bottom of L Lake, Savannah River Site, SC. The results will be used in the overall characterization of L Lake by providing continuous profile line coverage of the bottom and subbottom sediment structure along the entire length of the project area. The results are also intended to supplement previous scientific information obtained from soil samples, aerial photography, and radiometric studies. Resultant information will be used as input for an Environmental Impact Statement of the site. Overall, the seismic reflection data will provide better descriptions of variations in the actual subbottom conditions and help identify the differing sediment layers. The side scan sonar will help identify the location of the burial pits and any other features on the bottom of the reservoir. A 3.5 kiloHertz (kHz), high resolution subbottom profiling system and an EG and G Model 260 side scan sonar system were used to meet the primary objectives of the investigation

Remote sensing using hydroacoustics preliminary results

International Nuclear Information System (INIS)

Hunt, G.; Patrick, P.H.; Sim, B.

1989-01-01

A laboratory investigation was conducted to determine the capability and accuracy of a dual beam sonar system in classifying various targets. The ability to classify fish and/or distinguish fish from debris is essential if hydroacoustics are ever to be used truly remotely for hydroelectric power plant fish passage facilities. Preliminary results indicated that considerable filtering was occurring in the sonar sounder which limited its use in target classification. A wideband sonar detection module was developed which allowed for a more detailed reflected signal which probably will be necessary for fish identification. Another advantage that this modification appears to have over the existing system is an improved spatial resolution of targets, which can be significant if biomass estimates are based on echo counting techniques rather than echo integration ones. Based on the results, it may be possible to filter out or remove the influence of air bubbles in echo returns. As a result echo counts could more accurately be defined as fish counts. Target strengths of sturgeon were estimated using both the modified and original sounder. 12 refs., 11 figs., 2 tabs

Wave kinematics and response of slender offshore structures. Vol 3: Description of measuring systems

Energy Technology Data Exchange (ETDEWEB)

Riber, H.J.

1999-08-01

The report presents the measuring systems used during the measurements in the North Sea at the Tyra field. The report consists of two parts: (1) Description of the wave measuring systems (WMS); (2) Description of the load mesuring system (LMS). The developed Wave Kinematics Measuring Systems (WMS) is an acoustic system based on the pulsed incoherent Doppler technique. Basically it consists of 4 sonar stations and a control and monitoring station. The sonar stations are positioned at the seabed north of the TCP-A platform in a star configuration with one station surrounded by the other three stations in a fixed distance of 37 m. From the central sonar stations an umbilical is routed to the TCP-A platform where the control and monitoring stations is positioned in the satellite communication room. The measurement periods have been concentrated to periods with storms. It was a special emphasis to measure the wave kinematics of extremely high waves. The LMS is described in terms of geometrical data, structural properties, instrumentation, and other characteristics. (LN)

Modular Towed Acoustic Sonar Array

Science.gov (United States)

2014-02-04

Dkt . No...d 11 5 11 0c 11 0d 11 5 14 0 16 0’ 1 60 ’’ 12 0 14 0 12 0 14 0 13 0 14 0 12 0 13 0 12 0 12 0 13 0 14 0 16 0 10 0 d 2 d 3 Dkt . No. 102060 Application...of Non-Acoustic Sensors in Second Sensor Array Dkt . No. 102060 Application No. ?? REPLACEMENT SHEET? /3 1st DRAFT 3 F IG . 3 11 5 16 4 16 8 16 2 16 6 11 5 1 50 11 0b 18 0 17 0 16 6a 16 4a 18 0 10 0 11 0a 15 0

Psychoacoustics and Passive Sonar Detection

Science.gov (United States)

1974-09-09

not matched to the signal duration. This simple physical model provides a faiily credible replica of the detection performance of the ear, under...al., 1956; Veniar, 1958; Swets, Shipley, McKey und Gree^., 1959; Creelman , 1960; Green, 1961; and Gundy, 1961). In general, the experiments first...Acoust. Soc. Am. 3_7. 1064, (1965). 5. CD. Creelman , "Detection of Signals of Uncertain Frequency", J. Acoust. Soc. Am. 32, 805, (1960). 6. J.P

Advanced radar detection schemes under mismatched signal models

CERN Document Server

Bandiera, Francesco

2009-01-01

Adaptive detection of signals embedded in correlated Gaussian noise has been an active field of research in the last decades. This topic is important in many areas of signal processing such as, just to give some examples, radar, sonar, communications, and hyperspectral imaging. Most of the existing adaptive algorithms have been designed following the lead of the derivation of Kelly's detector which assumes perfect knowledge of the target steering vector. However, in realistic scenarios, mismatches are likely to occur due to both environmental and instrumental factors. When a mismatched signal

Highlights and Opportunities from Continuous Access to Gas Hydrates Sites at Ocean Networks Canada's NEPTUNE Observatory

Science.gov (United States)

Scherwath, M.; Heesemann, M.; Riedel, M.; Thomsen, L.; Roemer, M.; Chatzievangelou, D.; Purser, A.

2017-12-01

Since 2009 Ocean Networks Canada provides permanent access and continuous data in near real-time from two prominent gas hydrates research sites at the Northern Cascadia Margin, Barkley Canyon and Clayoquot Slope off Vancouver Island, through power and communication cables directly from shore. We show data highlights from the seafloor crawler Wally, the world's first internet operated vehicle, in a field of hydrate mounds and outcropping gas hydrates, and its co-located sonars and state-of-the-ocean sensors and Barkley Canyon. For example, spectacular views from the benthic communities and their changes over time are captured by video. At Clayoquot Slope highly active gas seep fields are monitored with a rotating multibeam sonar and various other environmental sensors. In addition, newly installed geodetic sensors as well as an instrumented borehole in that area are now online and provide additional data on subduction-related deformation and potential links to gas discharge. These show-case examples highlight the benefits of co-located experiments that enable interdisciplinary research and also the ability for high-power and -bandwidth long-term monitoring at remote seafloor locations, that over time will provide baselines for environmental monitoring together with natural variability and potential long-term trends.

Junction detection and pathway selection

Science.gov (United States)

Peck, Alex N.; Lim, Willie Y.; Breul, Harry T.

1992-02-01

The ability to detect junctions and make choices among the possible pathways is important for autonomous navigation. In our script-based navigation approach where a journey is specified as a script of high-level instructions, actions are frequently referenced to junctions, e.g., `turn left at the intersection.' In order for the robot to carry out these kind of instructions, it must be able (1) to detect an intersection (i.e., an intersection of pathways), (2) know that there are several possible pathways it can take, and (3) pick the pathway consistent with the high level instruction. In this paper we describe our implementation of the ability to detect junctions in an indoor environment, such as corners, T-junctions and intersections, using sonar. Our approach uses a combination of partial scan of the local environment and recognition of sonar signatures of certain features of the junctions. In the case where the environment is known, we use additional sensor information (such as compass bearings) to help recognize the specific junction. In general, once a junction is detected and its type known, the number of possible pathways can be deduced and the correct pathway selected. Then the appropriate behavior for negotiating the junction is activated.

Active Thrusting Offshore Mount Lebanon: Source of the Tsunamigenic A.D. 551 Beirut-Tripoli Earthquake

Science.gov (United States)

Tapponnier, P.; Elias, A.; Singh, S.; King, G.; Briais, A.; Daeron, M.; Carton, H.; Sursock, A.; Jacques, E.; Jomaa, R.; Klinger, Y.

2007-12-01

On July 9, AD 551, a large earthquake, followed by a tsunami destroyed most of the coastal cities of Phoenicia (modern-day Lebanon). This was arguably one of the most devastating historical submarine earthquakes in the eastern Mediterranean. Geophysical data from the Shalimar survey unveils the source of this Mw=7.5 event: rupture of the offshore, hitherto unknown, 100?150 km-long, active, east-dipping Mount Lebanon Thrust (MLT). Deep-towed sonar swaths along the base of prominent bathymetric escarpments reveal fresh, west facing seismic scarps that cut the sediment-smoothed seafloor. The MLT trace comes closest (~ 8 km) to the coast between Beirut and Enfeh, where as 13 radiocarbon-calibrated ages indicate, a shoreline-fringing Vermetid bench suddenly emerged by ~ 80 cm in the 6th century AD. At Tabarja, the regular vertical separation (~ 1 m) of higher fossil benches, suggests uplift by 3 more comparable-size earthquakes since the Holocene sea-level reached a maximum ca. 7-6 ka, implying a 1500?1750 yr recurrence time. Unabated thrusting on the MLT likely orchestrated the growth of Mt. Lebanon since the late Miocene. The newly discovered MLT has been the missing piece in the Dead Sea Transform and eastern Mediterranean tectonic scheme. Identifying the source of the AD 551 event thus ends a complete reassessment of the sources of the major historical earthquakes on the various faults of the Lebanese Restraining Bend of the Levant Fault System (or Dead Sea Transform).

Use of high-frequency imaging sonar (DIDSON) to observe fish behaviour towards a surface trawl

Czech Academy of Sciences Publication Activity Database

Rakowitz, G.; Tušer, Michal; Říha, Milan; Jůza, Tomáš; Balk, H.; Kubečka, Jan

2012-01-01

Roč. 123, July (2012), s. 37-48 ISSN 0165-7836. [Fish Sampling with Active Methods. České Budějovice, 08.09.2010-11.09.2010] R&D Projects: GA ČR(CZ) GA206/07/1392 Grant - others:NFM(CZ) CZ 0091 Institutional support: RVO:60077344 Keywords : active sampling gear * trawl * fish avoidance behaviour * DIDSON * freshwater reservoir Subject RIV: EH - Ecology, Behaviour Impact factor: 1.695, year: 2012

A simple extension of “An alternative approach to sea surface aerodynamic roughness” by Zhiqiu Gao, Qing Wang, and Shouping Wang

Science.gov (United States)

Gao, Zhiqiu; Wang, Linlin; Bi, Xueyan; Song, Qingtao; Gao, Yuchao

2012-08-01

Based on the data previously collected during the Humidity Exchange over the Sea Main Experiment (HEXMAX), the methods used to parameterize aerodynamic roughness (z0), friction velocity (u*), and the neutral drag coefficient (CDN) under moderate wind speed conditions originally proposed by Gao et al. (2006) were extended by using the nondimensional significant wave height (gHs/u*2 or gHs/U10N2) instead of wave age (cp/u* or cp/U10N), where g is the acceleration of gravity, Hs is the significant wave height, U10Nis the horizontal wind speed at 10-m height under the neutral atmospheric condition, andcp is the phase velocity of the peak wave spectrum. The results show (1) u* = 0.024U10N(gHs/U10N2)-1/4, (2) z0 = 10 × exp[-4.797(gHs/u*2)1/6] or z0 = 10 × exp[-16.613(gHs/U10N2)1/4], and (3) CDN = 0.007(gHs/u*2)-1/3 or CDN = 5.76 × 10-4(gHs/U10N2)-1/2. The present parameterization schemes were experimentally tested.

Seep Detection using E/V Nautilus Integrated Seafloor Mapping and Remotely Operated Vehicles on the United States West Coast

Science.gov (United States)

Gee, L. J.; Raineault, N.; Kane, R.; Saunders, M.; Heffron, E.; Embley, R. W.; Merle, S. G.

2017-12-01

Exploration Vessel (E/V) Nautilus has been mapping the seafloor off the west coast of the United States, from Washington to California, for the past three years with a Kongsberg EM302 multibeam sonar. This system simultaneously collects bathymetry, seafloor and water column backscatter data, allowing an integrated approach to mapping to more completely characterize a region, and has identified over 1,000 seafloor seeps. Hydrographic multibeam sonars like the EM302 were designed for mapping the bathymetry. It is only in the last decade that major mapping projects included an integrated approach that utilizes the seabed and water column backscatter information in addition to the bathymetry. Nautilus mapping in the Eastern Pacific over the past three years has included a number of seep-specific expeditions, and utilized and adapted the preliminary mapping guidelines that have emerged from research. The likelihood of seep detection is affected by many factors: the environment: seabed geomorphology, surficial sediment, seep location/depth, regional oceanography and biology, the nature of the seeps themselves: size variation, varying flux, depth, and transience, the detection system: design of hydrographic multibeam sonars limits use for water column detection, the platform: variations in the vessel and operations such as noise, speed, and swath overlap. Nautilus integrated seafloor mapping provided multiple indicators of seep locations, but it remains difficult to assess the probability of seep detection. Even when seeps were detected, they have not always been located during ROV dives. However, the presence of associated features (methane hydrate and bacterial mats) serve as evidence of potential seep activity and reinforce the transient nature of the seeps. Not detecting a seep in the water column data does not necessarily indicate that there is not a seep at a given location, but with multiple passes over an area and by the use of other contextual data, an area may

76 FR 4637 - Taking and Importing Marine Mammals; U.S. Navy's Atlantic Fleet Active Sonar Training

Science.gov (United States)

2011-01-26

... tagged whales for future molecular determination of the gender of these individuals. Passive Acoustic... components being used to address specific monitoring questions presented in the AFAST monitoring [[Page 4639... independent sightings, and six sightings were seen by both the MMOs and the Navy lookouts. A qualitative...

Application of the T-Matrix Method to the Numerical Modeling of a Linear Active Sonar Array

Science.gov (United States)

2013-06-01

coincides with the material ”3“ direction. Electrodes are located on the inner and outer surfaces of the sphere to form equipotential surfaces . Hence...shell transducer. . . . 49 Figure 4.17 A parametrized spherical surface was created at radii of 0.5 m (shown in red; The great circles are on the...34 Table 4.4 Comparison of the free-field radiated pressure at the surface of the spher- ical transducer computed in COMSOL against those

Filling of a Salt-withdrawal Minibasin on the Continental Slope by Turbidity Currents: Futher Research and Results

Science.gov (United States)

Violet, J. A.; Sheets, B. A.; Paola, C.; Pratson, L. F.; Parker, G.

2002-12-01

We illustrate further research results on the transport and deposition of sediment by turbidity currents in an experimental basin, designed to model salt-withdrawal minibasins found along the northern continental slope of the Gulf of Mexico. The experiment was performed in 2001 in the subsiding EXperimental EarthScape facility (XES) at St. Anthony Falls Laboratory, University of Minnesota. The run consisted of two stages that each contained the same sequence of events, which were of three different variations (1.85-minute pulses of 1.5 liters/s discharges, 3.8-minute pulses of 4.5 liters/s discharges, or 36 minute events of 1.5 liters/s discharges). The sediment comprised three grades of silica with nominal diameters of 20 microns (45%), 45 microns (40%) and 110 microns (15%) and all flows had a volume concentration of sediment of 5%. The only difference between stage I and II was that no subsidence occurred during stage II, and that the 110 micron sand was removed from the flows late in stage II to study the effects of a smaller mean flow-grainsize. Research since the run has focused on the correction of high-frequency sonar data taken during the run, digital photography taken of dried deposit stratigraphy and grainsize data also taken at various locations in the dried deposit. The sonar data is utilized in the creation of post-event topographies and isopach maps to illustrate what the controls on erosion, deposition, flow path, deposit thickness and even the channelization of early flow events are. Comparisons of the stratigraphy and the grainsize data with the conclusions from the sonar data are made, as sonar is also constructed in a manner that exhibits synthetic or predicted stratigraphy (before compaction). Finally the stratigraphy is structurally described in the proximal, medial, and distal segments of the deposit and comparisons to the field are made.

Seafloor geomorphology and geology of the Kingman Reef-Palmyra Atoll region, Central Pacific Ocean

Science.gov (United States)

Eakins, Barry; Barth, Ginger; Scheirer, Dan; Mosher, Dave; Armstrong, Andy

2017-04-01

Kingman Reef and Palmyra Atoll are the exposed summits of two seamounts within the Line Islands Volcanic Chain in the Central Pacific Ocean. Both are U.S. Territories, and the Exclusive Economic Zone around the islands was partially surveyed in 1991 with GLORIA sidescan sonar and seismic reflection profiling. New multibeam swath sonar surveys were conducted in 2010, 2015, and 2016 around the islands, in support of U.S. Extended Continental Shelf investigations. Numerous transits through the region by research vessels have collected additional multibeam swath sonar data. We present new, detailed maps of bathymetry, sidescan sonar imagery, geology, and sediment isopachs of the seafloor surrounding the islands, and how these have informed our understanding of the islands' margins. The islands are the last subaerial remnants of a complex, horse-shoe-shaped volcanic platform spanning roughly 200 km in diameter. The elevated platform from which the seamounts arise comprises at least 10 individual volcanic centers that have heights exceeding 3000m above the nearby abyssal plains. Gravity modeling suggests that the elevated platform is compensated by thickened crust. Strong carbonate caps and voluminous sediment accumulations flanking the platform indicate that the volcanoes were once shallow-water or emergent systems. These systems produced vast quantities of carbonate sediment that were shed to a deep interior basin to the east of Palmyra Atoll, and to nearby abyssal plains. The identification of mass failures, sediment reworking and bedforms, and channel networks provide evidence for extensive sedimentary processes around these volcanic centers. Analysis of the seamounts atop the elevated platform and in the seamount province to the northwest shows that flat-topped seamounts ("guyots") are principally found at depths shallower than 1300 meters, while peaked seamounts are almost exclusively found at greater depths. This constrains the amount of regional subsidence that

Operationele Oceanografie en Rapid Environmental Assessment (Operational Oceanography and Rapid Environmental Assessment)

National Research Council Canada - National Science Library

te Raa, L. A; Lam, F. P; Schouten, M. W

2008-01-01

.... Possible applications of operational oceanography in REA include improved sonar performance predictions with three-dimensional sound speed forecasts, support of AUV mission planning with the help...

Propagation and Signal Modeling

Science.gov (United States)

Jensen, Finn B.

The use of sound in the sea is ubiquitous: Apart from the military aspect of trying to detect an adversary’s mines and submarines, ship-mounted sonars measure water depth, ship speed, and the presence of fish shoals. Side-scan systems are used for mapping the bottom topography, sub-bottom profilers for getting information about the deeper layering, and other sonar systems for locating pipelines and cables on the seafloor. Sound is also used for navigating submerged vehicles, for underwater communications and for tracking marine mammals. Finally, in the realm of ‘acoustical oceanography’ and ‘ocean acoustic tomography,’ sound is used for measuring physical parameters of the ocean environment and for monitoring oceanic processes [1-6].

Geometry of sandy deposits at the distal edge of the Mississippi Fan, Gulf of Mexico

Science.gov (United States)

Twichell, D.C.; Schwab, W.C.; Kenyon, Neil H.

1995-01-01

Sidescan sonar provides a map of the seafloor that has greatly improved the understanding of depositional processes on modern deep-sea fans (e.g. Mutti and Normark 1991). Here, we present a sidescan-sonar mosaic from the eastern Gulf of Mexico that images the distal reaches of a channel on the Mississippi Fan and the deposits associated with it (Fig. 41.1). This area is one of several deep-sea fan systems that had not previously been imaged by high-resolution sidescan systems. The mosaic highlights the complexity of the spatial relationships of channels and deposits at ends of channels on this large, modern, passive-margin deep-sea fan (Figs 41.2 and 41.3).

Apparatus for ultrasonic visualization in sodium (VISUS) and acoustic detection in the Phenix reactor

International Nuclear Information System (INIS)

Lions, M.; Berger, R.; Bret, A.; Buis, H.; Barton, J.

A description is given of two acoustic monitoring systems studied at the Fast Neutron Reactor Department at CEN/Cadarache and used in the Phenix reactor. The first is the active type, and the second, passive. The active apparatus is based on the sonar principle and permits visualizing objects inside a reactor tank, especially the heads of assemblies during handling. The passive apparatus, the acoustic detector, observes the reactor core by analyzing the acoustic noise produced in the reactor core. The electroacoustic converters are in both cases located outside, and the acoustic vibrations are transmitted by wave guides. The two pieces of apparatus can operate in a hostile environment, such as liquid metal at high temperature in the presence of high neutron and gamma fluxes

Proceedings of the Adaptive Sensor Array Processing Workshop (12th) Held in Lexington, MA on 16-18 March 2004 (CD-ROM)

National Research Council Canada - National Science Library

James, F

2004-01-01

...: The twelfth annual workshop on Adaptive Sensor Array Processing presented a diverse agenda featuring new work on adaptive methods for communications, radar and sonar, algorithmic challenges posed...

Identifying and localizing network problems using the PuNDIT project

International Nuclear Information System (INIS)

Batista, Jorge; McKee, Shawn; Dovrolis, Constantine; Lee, Danny

2015-01-01

In today's world of distributed collaborations of scientists, there are many challenges to providing effective infrastructures to couple these groups of scientists with their shared computing and storage resources. The Pythia Network Diagnostic InfrasTructure (PuNDIT[1]) project is integrating and scaling research tools and creating robust code suitable for operational needs addressing the difficult challenge of automating the detection and location of network problems.PuNDIT is building upon the de-facto standard perfSONAR[2] network measurement infrastructure deployed in Open Science Grid(OSG)[3] and the Worldwide LHC Computing Grid(WLCG)[4]to gather and analyze complex real-world network topologies coupled with their corresponding network metrics to identify possible signatures of network problems from a set of symptoms. The PuNDIT Team is working closely with the perfSONAR developers from ESnet and Internet2 to integrate PuNDIT components as part of the perfSONAR Toolkit. A primary goal for PuNDIT is to convert complex network metrics into easily understood diagnoses in an automated way. We will report on the project progress to-date in working with the OSG and WLCG communities, describe the current implementation including some initial results and discuss future plans and the project timeline. (paper)

Mapping nuclear craters on Enewetak Atoll, Marshall Islands

Science.gov (United States)

Hampson, John C., Jr.

1986-01-01

In 1984, the U.S. Geological Survey conducted a detailed geologic analysis of two nuclear test craters at Enewetak Atoll, Marshall Islands, on behalf of the Defense Nuclear Agency. A multidisciplinary task force mapped the morphology, surface character, and subsurface structure of two craters, OAK and KOA. The field mapping techniques include echo sounding, sidescan sonar imaging, single-channel and multichannel seismic reflection profiling, a seismic refraction survey, and scuba and submersible operations. All operations had to be navigated precisely and correlatable with subsequent drilling and sampling operations. Mapping with a high degree of precision at scales as large as 1:1500 required corrections that often are not considered in marine mapping. Corrections were applied to the bathymetric data for location of the echo- sounding transducer relative to the navigation transponder on the ship and for transducer depth, speed of sound, and tidal variations. Sidescan sonar, single-channel seismic reflection, and scuba and submersible data were correlated in depth and map position with the bathymetric data to provide a precise, internally consistent data set. The multichannel and refraction surveys were conducted independently but compared well with bathymetry. Examples drawn from processing the bathymetric, sidescan sonar, and single- channel reflection data help illustrate problems and procedures in precision mapping.

Geomorphology of the Southern Gulf of California Seafloor

Science.gov (United States)

Eakins, B. W.; Lonsdale, P. F.; Fletcher, J. M.; Ledesma, J. V.

2004-12-01

A Spring 2004 multibeam sonar survey defined the seafloor geomorphology of the southern part of Gulf of California and the intersection of the East Pacific Rise with the North American continent. Survey goals included mapping structural patterns formed during the rifting that opened the Gulf and identifying the spatial transition from continental rifting to seafloor spreading. Multibeam sonar imagery, augmented with archival data and a subaerial DEM of Mexico, illuminates the principal features of this boundary zone between obliquely diverging plates: (i) active and inactive oceanic risecrests within young oceanic basins that are rich in evidence for off-axis magmatic eruption and intrusion; (ii) transforms with pull-apart basins and transpressive ridges along shearing continental margins and within oceanic crust; (iii) orphaned blocks of continental crust detached from sheared and rifted continental margins; and (iv) young, still-extending continental margins dissected by submarine canyons that in many cases are deeply drowned river valleys. Many of the canyons are conduits for turbidity currents that feed deep-sea fans on oceanic and subsided continental crust, and channel sediment to spreading axes, thereby modifying the crustal accretion process. We present a series of detailed bathymetric and seafloor reflectivity maps of this MARGINS Rupturing Continental Lithosphere focus site illustrating geomorphologic features of the southern part of the Gulf, from Guaymas Basin to the Maria Magdalena Rise.

Adaptive High Frequency Laser Sonar System

National Research Council Canada - National Science Library

Cray, Benjamin A

2007-01-01

.... Antivibration mounts are joined between said scanning laser vibrometer and said housing. In further embodiments, the scanning laser vibrometer detects vibrations at a plurality of locations on the acoustic window forming a virtual array...

The M6 1799 Vendée intraplate earthquake (France) : characterizing the active fault with a multidisciplinary approach.

Science.gov (United States)

Kaub, C.; Perrot, J.; Le Roy, P., Sr.; Authemayou, C.; Bollinger, L.; Hebert, H.; Geoffroy, L.

2017-12-01

The coastal Vendee (France) is located to the south of the intraplate Armorican area. This region is affected by a system of dominantly NW-SE trending shear zones and faults inherited from a long and poly-phased tectonic history since Variscan times. This area currently presents a moderate background seismic activity, but was affected by a significant historical earthquake (magnitude M 6) on the 1799 January 25th. This event generated particularly strong site effects in a Neogene basin located along a major onshore/offshore discontinuity bounding the basin, the Machecoul fault. The objective of this study is to identify and qualify active faults potentially responsible for such major seismic event in order to better constrain the seismic hazard of this area. We adopt for this purpose a multidisciplinary approach including an onshore seismological survey, high-resolution low-penetration offshore seismic data (CHIRP echo sounder, Sparker source and single channel streamer), high-resolution interferometric sonar bathymetry (GeoSwath), compilation of onshore drilling database (BSS, BRGM), and quantitative geomorphology In the meantime, the seismicity of the area was characterized by a network of 10 REFTEK stations, deployed since January 2016 around the Bay of Bourgneuf (MACHE network). About 50 local earthquakes, with coda magnitudes ranging from 0.5 to 3.1 and local magnitude ranging from 0.2 to 2.9 were identified so far. This new database complement a local earthquake catalog acquired since 2011 from previous regional networks. We surveyed the fault segments offshore, in the Bay of Bourgneuf, analyzing 700 km of high-resolution seismic profiles and 40 km² of high-resolution bathymetry acquired during the RETZ1 (2016) and RETZ2 (2017) campaigns, in addition to HR-bathymetry along the fault scarp. Those data are interpreted in conjunction with onshore wells to determine if (and since when) the Machecoul fault controlled tectonically the Neogene sedimentation.

Long Island Sound Environmental Studies; 01 October 1991 to 31 August 1998 (NODC Accession 9900223)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Abstract: This CD-ROM (Compact Disk - Read Only Memory) contains sidescan sonar, high-resolution seismic-reflection, bathymetric, textural, and bibliographic data...

Underwater Acoustic Signal Processing

National Research Council Canada - National Science Library

Culver, Richard L; Sibul, Leon H; Bradley, David L

2007-01-01

.... The research is directed toward passive sonar detection and classification, continuous wave (CW) and broadband signals, shallow water operation, both platform-mounted and distributed systems, and frequencies below 1 kHz...

Multibeam Mapping of the West Florida Shelf, Gulf of Mexico, Twin Ridges Area

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — XYZ ASCII format high-resolution bathymetry data generated from the 2002 multibeam sonar survey of the West Florida Shelf, Gulf of Mexico.

Submarine Ring of Fire 2014 - Ironman

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — There will be 4 primary data types collected, multibeam sonar data, CTD water column data, hydrophone records, and Jason ROV dive data.

Olympic Coast National Marine Sanctuary - hab122_0702 - Habitat polygons for HMPR-122-2007-02 survey

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Benthic habitat polygon coverages are being created for the Olympic Coast National Marine Sanctuary (OCNMS). OCNMS has collected side scan sonar, multibeam...

Multibeam Mapping of the West Florida Shelf, Gulf of Mexico, Madison Swanson Area

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — XYZ ASCII format high-resolution bathymetry data generated from the 2002 multibeam sonar survey of the West Florida Shelf, Gulf of Mexico.

Habitat information in the region on the underwater San Andreas Fault - Topic: Exploring the Undersea San Andreas Fault: Revealing the Past, Present, and Future at the Centennial of the Great 1906 Earthquake

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — During this exploration, the first comprehensive high-resolution multi-beam sonar and seismic reflection survey of the Northern San Andreas Fault (NSAF) was...

AFSC/ABL: Multibeam Database

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Seafloor habitat maps have been created using high resolution multibeam sonar with co-registered backscatter at various locations throughout the Alaska Region. Most...

Okeanos Explorer (EX1404L2): Our Deepwater Backyard: Exploring the Atlantic Canyons and Seamounts

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — High resolution mapping data from vessel multibeam and submersible sonar systems; singlebeam and sub-bottom profile data; periodic CTD casts; submersible CTD data;...

Okeanos Explorer (EX1404L3): Northeast Seamounts and Canyons

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — High resolution mapping data from vessel multibeam and submersible sonar systems; singlebeam and sub-botoom profile data; periodic CTD casts; submersible CTD data;...

Robot Mapping With Real-Time Incremental Localization Using Expectation Maximization

National Research Council Canada - National Science Library

Owens, Kevin L

2005-01-01

This research effort explores and develops a real-time sonar-based robot mapping and localization algorithm that provides pose correction within the context of a singe room, to be combined with pre...

Applications of Piezoelectric Ceramics

Indian Academy of Sciences (India)

Applications of Piezoelectric Ceramics. Piezoelectric Actuators. Nano and Micropositioners. Vibration Control Systems. Computer Printers. Piezoelectric Transformers,Voltage Generators, Spark Plugs, Ultrasonic Motors,. Ultrasonic Generators and Sensors. Sonars, Medical Diagnostic. Computer Memories. NVFRAM ...

Sensor fusion-based map building for mobile robot exploration

International Nuclear Information System (INIS)

Ribo, M.

2000-01-01

To carry out exploration tasks in unknown or partially unknown environments, a mobile robot needs to acquire and maintain models of its environment. In doing so, several sensors of same nature and/or heterogeneous sensor configurations may be used by the robot to achieve reliable performances. However, this in turn poses the problem of sensor fusion-based map building: How to interpret, combine and integrate sensory information in order to build a proper representation of the environment. Specifically, the goal of this thesis is to probe integration algorithms for Occupancy Grid (OG) based map building using odometry, ultrasonic rangefinders, and stereo vision. Three different uncertainty calculi are presented here which are used for sensor fusion-based map building purposes. They are based on probability theory, Dempster-Shafer theory of evidence, and fuzzy set theory. Besides, two different sensor models are depicted which are used to translate sensing data into range information. Experimental examples of OGs built from real data recorded by two robots in office-like environment are presented. They show the feasibility of the proposed approach for building both sonar and visual based OGs. A comparison among the presented uncertainty calculi is performed in a sonar-based framework. Finally, the fusion of both sonar and visual information based of the fuzzy set theory is depicted. (author)

Sea-floor geology and character offshore of Rocky Point, New York

Science.gov (United States)

Poppe, L.J.; McMullen, K.Y.; Ackerman, S.D.; Blackwood, D.S.; Irwin, B.J.; Schaer, J.D.; Lewit, P.G.; Doran, E.F.

2010-01-01

The U.S. Geological Survey (USGS), the Connecticut Department of Environmental Protection, and the National Oceanic and Atmospheric Administration (NOAA) have been working cooperatively to interpret surficial sea-floor geology along the coast of the Northeastern United States. NOAA survey H11445 in eastern Long Island Sound, offshore of Plum Island, New York, covers an area of about 12 square kilometers. Multibeam bathymetry and sidescan-sonar imagery from the survey, as well as sediment and photographic data from 13 stations occupied during a USGS verification cruise are used to delineate sea-floor features and characterize the environment. Bathymetry gradually deepens offshore to over 100 meters in a depression in the northwest part of the study area and reaches 60 meters in Plum Gut, a channel between Plum Island and Orient Point. Sand waves are present on a shoal north of Plum Island and in several smaller areas around the basin. Sand-wave asymmetry indicates that counter-clockwise net sediment transport maintains the shoal. Sand is prevalent where there is low backscatter in the sidescan-sonar imagery. Gravel and boulder areas are submerged lag deposits produced from the Harbor Hill-Orient Point-Fishers Island moraine segment and are found adjacent to the shorelines and just north of Plum Island, where high backscatter is present in the sidescan-sonar imagery.

Surficial geology of the sea floor in Long Island Sound offshore of Plum Island, New York

Science.gov (United States)

McMullen, K.Y.; Poppe, L.J.; Danforth, W.W.; Blackwood, D.S.; Schaer, J.D.; Ostapenko, A.J.; Glomb, K.A.; Doran, E.F.

2010-01-01

The U.S. Geological Survey (USGS), the Connecticut Department of Environmental Protection, and the National Oceanic and Atmospheric Administration (NOAA) have been working cooperatively to interpret surficial sea-floor geology along the coast of the Northeastern United States. NOAA survey H11445 in eastern Long Island Sound, offshore of Plum Island, New York, covers an area of about 12 square kilometers. Multibeam bathymetry and sidescan-sonar imagery from the survey, as well as sediment and photographic data from 13 stations occupied during a USGS verification cruise are used to delineate sea-floor features and characterize the environment. Bathymetry gradually deepens offshore to over 100 meters in a depression in the northwest part of the study area and reaches 60 meters in Plum Gut, a channel between Plum Island and Orient Point. Sand waves are present on a shoal north of Plum Island and in several smaller areas around the basin. Sand-wave asymmetry indicates that counter-clockwise net sediment transport maintains the shoal. Sand is prevalent where there is low backscatter in the sidescan-sonar imagery. Gravel and boulder areas are submerged lag deposits produced from the Harbor Hill-Orient Point-Fishers Island moraine segment and are found adjacent to the shorelines and just north of Plum Island, where high backscatter is present in the sidescan-sonar imagery.

San Francisco Bay Interferometric Bathymetry: Area B

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — High resolution sonar data were collected over ultra-shallow areas of the San Francisco Bay estuary system. Bathymetric and acoustic backscatter data were collected...

AWI Moored ULS Data, Greenland Sea and Fram Strait, 1991-2002, Version 1

Data.gov (United States)

National Aeronautics and Space Administration — This data set consists of Upward Looking Sonar (ULS) data from 11 moorings in the Greenland Sea. Parameters in the processed data files include ice draft, water...

Okeanos Explorer (EX1403): East Coast Mapping and Exploration

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Multibeam, single beam, and subbottom sonar data will be collected 24 hours a day. XBT casts will be conducted regularly for multibeam calibration. The ship's...

Search for the Lost French Fleet of 1565

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The study will conduct a seven-day geophysical survey using magnetometer, sidescan sonar, and sub-bottom profiler to identify targets. On two subsequent six-day...

Okeanos Explorer (EX1402L3): Gulf of Mexico Mapping and ROV Exploration

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Multibeam mapping, single beam, water column sonar, sub-bottom profile, water column profile, ship sensor, ROV sensor, video and image data will all be collected...

EX1302: Ship Shakedown, Patch Test and Exploration, NE Canyons and Seamounts on NOAA Ship Okeanos Explorer between 20130513 and 20130606

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Between May 13 and May 18, shakedown operations will: ensure all scientific sonars are in good working order after dry dock operations; assess noise reduction...

Oceanographic data collected during the EX1302 (Ship Shakedown, Patch Test and Exploration, NE Canyons) expedition on NOAA Ship OKEANOS EXPLORER in the North Atlantic Ocean from 2013-05-13 to 2013-06-06 (NODC Accession 0108363)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Between May 13 and May 18, shakedown operations will: ensure all scientific sonars are in good working order after dry dock operations; assess noise reduction...

Prototype development of a piezo-heating array for deicing application on bridges : final report.

Science.gov (United States)

2017-01-01

A novel piezoelectric transducer was designed and fabricated to demonstrate energy harvesting from traffic-induced loading on pavement. The piezoelectric transducer is based on the cymbal transducer design used for underwater acoustic and sonar...

Gridded bathymetry of Barbers Point, Oahu Hawaii, USA

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Gridded bathymetry (1m) of Barbers Point ship grounding site, Oahu, Hawaii, USA. The data include multibeam bathymetry from the Reson 8101 multibeam sonar collected...

Multibeam Mapping of the West Florida Shelf-The Edges, Gulf of Mexico, Appalachicola, Florida.

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — XYZ ASCII format high-resolution bathymetry data generated from the 2010 multibeam sonar survey of the West Florida Shelf-The Edges, Gulf of Mexico, Appalachicola,...

Hydroacoustic detection of dumped ammunition in the Ocean with multibeam snippet backscatter analyses. A case study from the 'Kolberger Heide' ammunition dump site (Baltic Sea, Germany)

Science.gov (United States)

Kunde, Tina; Schneider von Deimling, Jens

2016-04-01

Dumped ammunition in the sea is a matter of great concern in terms of safe navigation and environmental threads. Because corrosion of the dumped ammunition's hull is ongoing, future contamination of the ambient water by their toxic interior is likely to occur. The location of such dump sites is approximately known from historical research and ship log book analyses. Subsequent remote sensing of ammunition dumping sites (e.g. mines) on the seafloor is preferentially performed with hydro-acoustic methods such as high resolution towed side scan or by the sophisticated synthetic aperture sonar approach with autonomous underwater vehicles. However, these are time consuming and expensive procedures, while determining the precise position of individual mines remains a challenging task. To mitigate these shortcomings we suggest using ship-born high-frequency multibeam sonar in shallow water to address the task of mine detection and precise localization on the seabed. Multibeam sonar systems have improved their potential in regard to backscatter analyses significantly over the past years and nowadays present fast and accurate tools for shallow water surveying to (1) detect mines in multibeam snippet backscatter data (2) determine their precise location with high accuracy intertial navigation systems. A case study was performed at the prominent ammunition dumping site 'Kolberger Heide' (Baltic Sea, Germany) in the year 2014 using a modern hydro-acoustic multibeam echosounder system with 200-400 kHz (KONGSBERG EM2040c). With an average water depth of not even 20 m and the proximity to the shore line and dense waterways, this investigated area requires permanent navigational care. Previously, the study area was surveyed by the Navy with the very sophisticated HUGIN AUV equipped with a synthetic aperture sonar with best resolution by current technology. Following an evaluation of the collected data, various ammunition bodies on the sea floor could be clearly detected. Analyses

Obstacle Avoidance for Unmanned Undersea Vehicle in Unknown Unstructured Environment

Directory of Open Access Journals (Sweden)

Zheping Yan

2013-01-01

Full Text Available To avoid obstacle in the unknown environment for unmanned undersea vehicle (UUV, an obstacle avoiding system based on improved vector field histogram (VFH is designed. Forward looking sonar is used to detect the environment, and the divisional sonar modal is applied to deal with the measure uncertainty. To adapt to the VFH, rolling occupancy grids are used for the map building, and high accuracy details of local environment are obtained. The threshold is adaptively adjusted by the statistic of obstacles to solve the problem that VFH is sensitive to threshold. To improve the environment adaptability, the hybrid-behaviors strategy is proposed, which selects the optimal avoidance command according to the motion status and environment character. The simulation shows that UUV could avoid the obstacles fast and escape from the U shape obstacles.

Archive of Boomer Subbottom Data Collected During USGS Cruise SEAX 96004, New York Bight, 1 May - 9 June 1996

Science.gov (United States)

Hill, Jenna C.; Schwab, William C.; Foster, David S.

2000-01-01

Beginning in 1995, the USGS, in cooperation with the U.S Army Corps of Engineers (USACE), New York District, began a program to generate reconnaissance maps of the sea floor offshore of the New York-New Jersey metropolitan area, one of the most populated coastal regions of the United States. The goal of this mapping program is to provide a regional synthesis of the sea-floor environment, including a description of sedimentary environments, sediment texture, seafloor morphology, and geologic history to aid in understanding the impacts of anthropogenic activities, such as ocean dumping. This mapping effort differs from previous studies of this area by obtaining digital, sidescan sonar images that cover 100 percent of the sea floor.This investigation was motivated by the need to develop an environmentally acceptable solution for the disposal of dredged material from the New York - New Jersey Port, by the need to identify potential sources of sand for renourishment of the southern shore of Long island, and by the opportunity to develop a better understanding of the transport and long-term fate of contaminants by investigations of the present distribution of materials discharged into the New York Bight over the last 100+ years (Schwab and others, 1997). Data collected in 1996, USGS cruise SEAX 96004, augments data collected in 1995 with sidescan sonar and seismic reflection data collected within the New York Bight Apex region. This report is an archive of the boomer seismic reflection data collected in 1996.

Archive of water gun subbottom data collected during USGS cruise SEAX 96004, New York Bight, 1 May - 9 June 1996

Science.gov (United States)

Hill, Jenna C.; Schwab, William C.; Foster, David S.

2000-01-01

Beginning in 1995, the USGS, in cooperation with the U.S Army Corps of Engineers (USACE), New York District, began a program to generate reconnaissance maps of the sea floor offshore of the New York-New Jersey metropolitan area, one of the most populated coastal regions of the United States. The goal of this mapping program is to provide a regional synthesis of the sea-floor environment, including a description of sedimentary environments, sediment texture, seafloor morphology, and geologic history to aid in understanding the impacts of anthropogenic activities, such as ocean dumping. This mapping effort differs from previous studies of this area by obtaining digital, sidescan sonar images that cover 100 percent of the sea floor.This investigation was motivated by the need to develop an environmentally acceptable solution for the disposal of dredged material from the New York - New Jersey Port, by the need to identify potential sources of sand for renourishment of the southern shore of Long island, and by the opportunity to develop a better understanding of the transport and long-term fate of contaminants by investigations of the present distribution of materials discharged into the New York Bight over the last 100+ years (Schwab and others, 1997). Data collected in 1996, USGS cruise SEAX 96004, augments data collected in 1995 with sidescan sonar and seismic reflection data collected within the New York Bight Apex region. This report is an archive of the water gun seismic reflection data collected in 1996.

Structural contour, isopach and feature maps of quaternary sediments in Western Lake Ontario

International Nuclear Information System (INIS)

Lewis, C.F.M.; King, E.L.; Todd, B.J.; Blasco, S.M.

1995-06-01

A systematic high-resolution acoustic reconnaissance survey of Quaternary sediments (> 50 m thick, in places) and the underlying bedrock surface was completed for western Lake Ontario between Burlington and Port Hope, Ontario, to determine if geophysical lineaments through the area of Pickering and Darlington nuclear power stations are potentially seismically active. A total of 2530 line-km of data were obtained along N-S and E-W lines spaced 10 and 5 km respectively, using a high-resolution subbottom profiler (boomer and IKB-SEISTEC), a 100 kHz sidescan sonar (150-m range) with 3.5 kHz profiler, a 10 or 40 cu. in. sleeve gun seismic reflection system, and, intermittently, a marine magnetometer. Six piston cores up to 15-m long were collected to compare sediment lithology with key regional seismic reflectors. Sediments deposited over the past 13,000 years were imaged with vertical resolution in the order of 10-30 cm just below the lakebed and less than 1 m at the bedrock surface; resolution for the sleeve gun system is approximately 3-5 m. Digital processing and rescaling of selected seismic profiles aided interpretation. Structural contour maps for three Quaternary sequence boundaries and the bedrock surface were generated together with the related sequence isopach maps. Three additional maps portray lakebed features identified on sidescan sonar records and subsurface features identified on seismic profiles. All maps are at 1:250,000 scale. (author). 2 tabs., 48 figs., 12 maps

2010 ME70 Workshop (PC1003, EK60)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The third leg of the 2010 SEAMAP Reeffish Survey, PC 1003, was originally scheduled as an experimental multibeam sonar workshop. However, on July 12, 2010, FSV...

Significance of relic carbonate deposits along the central and southwestern margin of India for late Quaternary environmental and sea level changes

Digital Repository Service at National Institute of Oceanography (India)

Rao, V.P.; Montaggioni, L.; Vora, K.H.; Almeida, F.; Rao, K.M.; Rajagopalan, G.

Environmental and sea level indicators were investigated using dredge samples from late Quaternary carbonate deposits along the shelf break between Goa and Cape Comorin, India. Geomorphic features in the area were identified from sonar profiles...

Multibeam Mapping of Pulley Ridge, Gulf of Mexico, Key West, Florida

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — XYZ ASCII format high-resolution bathymetry data generated from the 2003, 2007, and 2009 combined multibeam sonar survey of Pulley Ridge, Gulf of Mexico, Key West,...

Bathymetry Mapping of the West Florida Shelf (Steamboat Lumps), Gulf of Mexico (NODC Accession 0001410)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — XYZ ASCII format data generated from the 2001 multibeam sonar survey of the West Florida Shelf, Gulf of Mexico. The data include high-resolution bathymetry and...

Backscatter Mapping of the West Florida Shelf (Southern Region), Gulf of Mexico (NODC Accession 0001410)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — XYZ ASCII format data generated from the 2001 multibeam sonar survey of the West Florida Shelf, Gulf of Mexico. The data include high-resolution bathymetry and...

Fish Density of El Seco, Puerto Rico from 2009-03-31 to 2009-04-02, Project NF-09-01-USVI, 2009, WGS84 (NCEI Accession 0137091)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — This data contains densities of fishes detected using mobile fisheries sonar on board NOAA Ship Nancy Foster. The data were acquired in concert with a multibeam...

Okeanos Explorer (EX1609): Main Hawaiian Island Shakedown

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Multibeam, split-beam, and/or ADCP sonar mapping operations will be conducted 24 hours a day throughout the cruise. Sub-bottom profile mapping will be conducted...

NOAA Point Shapefile - 100m2 Fish Density of El Seco, Puerto Rico, Project NF-09-01-USVI, 2009, WGS84

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — This data contains densities of fishes detected using mobile fisheries sonar on board the NOAA Ship Nancy Foster. The data were acquired in concert with a multibeam...

NOAA Point Shapefile - 100m2 Fish Density for Virgin Passage, United States Virgin Islands, Project NF-10-03-USVI, 2010, WGS84

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — This data contains densities of fishes detected using mobile fisheries sonar on board the NOAA Ship Nancy Foster. The data were acquired in concert with a multibeam...

AWI Moored ULS Data, Greenland Sea and Fram Strait, 1991-2002

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — This data set consists of Upward Looking Sonar (ULS) data from 11 moorings in the Greenland Sea. Parameters in the processed data files include ice draft, water...

Okeanos Explorer (EX1404L1): Shakedown and Mapping, NE Seamounts

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Multibeam, single beam, and subbottom sonar data will be collected 24 hours a day and XBT casts will be conducted at an interval defined by prevailing oceanographic...

Gridded multibeam bathymetry of Apra Harbor, Guam U.S. Territory

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Gridded bathymetry from Apra Harbor, Guam U.S. Territory. The netCDF and Arc ASCII grids include multibeam bathymetry from the Reson SeaBat 8125 multibeam sonar...

NOAA Point Shapefile - 100m2 Fish Density of Grand Northeast Ecological Corridor, Puerto Rico, Project NF-12-01-PR, 2012, WGS84

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — This data contains densities of fishes detected using mobile fisheries sonar on board the NOAA Ship Nancy Foster. The data were acquired in concert with a multibeam...

NOAA Point Shapefile - 100m2 Fish Density of Grand Northeast Ecological Corridor, Puerto Rico, Project NF-13-02-PR, 2013, WGS84

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — This data contains densities of fishes detected using mobile fisheries sonar on board the NOAA Ship Nancy Foster. The data were acquired in concert with a multibeam...

AWI Moored ULS Data, Weddell Sea (1990-1998)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — This data set consists of moored Upward Looking Sonar (ULS) data from 14 stations in the Weddell Sea. Parameters in the processed data files are water pressure,...

Oceanographic data collected during the EX1404L1 (Shakedown and Mapping, NE Seamounts) expedition on NOAA Ship OKEANOS EXPLORER in the North Atlantic Ocean from 2014-08-09 to 2014-08-30 (NCEI Accession 0121584)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Multibeam, single beam, and subbottom sonar data will be collected 24 hours a day and XBT casts will be conducted at an interval defined by prevailing oceanographic...

Transjugular Intrahepatic Portosystemic Shunt (TIPS)

Medline Plus

Full Text Available ... The principles are similar to sonar used by boats and submarines. The ultrasound image is immediately visible ... the hepatic vein to identify the portal venous system. Access is then gained from the hepatic vein ...

Transjugular Intrahepatic Portosystemic Shunt (TIPS)

Medline Plus

Full Text Available ... echoes from the tissues in the body. The principles are similar to sonar used by boats and ... bleeding resistant to traditional medical treatments. The greatest difference in performing TIPS in children is their tremendous ...

Numerical comparison of patch and sandwich piezoelectric transducers for transmitting ultrasonic waves

CSIR Research Space (South Africa)

Loveday, PW

2006-03-01

Full Text Available in the waveguide. Piezoelectric patch transducers are frequently employed, by researchers, for exciting waves in beam like structures. Sonar systems frequently make use of resonant transducers, such as sandwich transducers, for acoustic wave generation...

Children's (Pediatric) Abdominal Ultrasound Imaging

Medline Plus

Full Text Available ... video display screen and a transducer that is used to do the scanning. The transducer is a ... the body. The principles are similar to sonar used by boats and submarines. The ultrasound image is ...

Transjugular Intrahepatic Portosystemic Shunt (TIPS)

Medline Plus

Full Text Available ... echoes from the tissues in the body. The principles are similar to sonar used by boats and ... smaller than a "pencil lead", or approximately 1/8 inch in diameter. The stent used in this ...

Submarine physiography off Lakshadweep Islands, Arabian Sea

Digital Repository Service at National Institute of Oceanography (India)

Chauhan, O.S; Chaubey, A

Analysis of echosoundings, side scan sonar and shallow seismic data, supplementEd. by 152 sediment samples, collected along 150 km around Lakshadweep Islands, Arabian Sea, revealed that the islands have a very narrow shelf, and an abrupt, shelf...

DIDSON ultrasonic video data - Untrawlable Habitat Strategic Initiative

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The NWFSC FRAM Marine Habitat Ecology Team is involved in many aspects of the UHSI program but has focused on the application of DIDSON imaging sonars to aid in...

77 FR 19321 - Geological and Geophysical Exploration on the Atlantic Outer Continental Shelf (OCS)

Science.gov (United States)

2012-03-30

... DEPARTMENT OF THE INTERIOR Bureau of Ocean Energy Management Geological and Geophysical... Statement (PEIS) to evaluate potential environmental effects of multiple Geological and Geophysical (G&G... limited to, seismic surveys, sidescan-sonar surveys, electromagnetic surveys, geological and geochemical...

Heavy mineral occurrence off Hazira, west coast of India

Digital Repository Service at National Institute of Oceanography (India)

Vora, K.H.; Mislankar, P.G.; Gujar, A.R.

The occurrence of heavy mineral placers on the west coast of India are well known from Konkan and Malabar Coast. However, a geological and geophysical investigation (including echosounding and side scan sonar profiles and 7 samples) off Hazira...

Benthic Mapping in Long Island Sound

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — QTCView is used with an incorporated depthfinder to create a sonar map of the bottom to the west of the Charles Island, in Long Island Sound in Connecticut waters....

Seabed surveys of Mormugao Harbour, Central west coast of India

Digital Repository Service at National Institute of Oceanography (India)

Wagle, B.G.; Gujar, A.R.; Subrahmanyam, V.; Mislankar, P.G.

Detailed echosounding, side scan sonar and shallow seismics (125 line km) covering an area of 6.2 km2 in the Mormugao harbour provided information on seabed topography, surficial distribution of sediments, their thickness and rock outcrops along...

Analog VLSI Models of Range-Tuned Neurons in the Bat Echolocation System

Directory of Open Access Journals (Sweden)

Horiuchi Timothy

2003-01-01

Full Text Available Bat echolocation is a fascinating topic of research for both neuroscientists and engineers, due to the complex and extremely time-constrained nature of the problem and its potential for application to engineered systems. In the bat's brainstem and midbrain exist neural circuits that are sensitive to the specific difference in time between the outgoing sonar vocalization and the returning echo. While some of the details of the neural mechanisms are known to be species-specific, a basic model of reafference-triggered, postinhibitory rebound timing is reasonably well supported by available data. We have designed low-power, analog VLSI circuits to mimic this mechanism and have demonstrated range-dependent outputs for use in a real-time sonar system. These circuits are being used to implement range-dependent vocalization amplitude, vocalization rate, and closest target isolation.

High-resolution multibeam bathymetry of East and West Flower Gardens and Stetson Banks, Gulf of Mexico

Science.gov (United States)

Gardner, J.V.; Mayer, L.A.; Hughes, Clarke J.E.; Kleiner, A.

1998-01-01

The 1990s have seen rapid advances in seafloor mapping technology. Multibeam sonars are now capable of mapping a wide range of water depths with beams as narrow as 1??, and provide up to a 150?? swath. When these multibeam sonars are coupled with an extremely accurate vehicle motion sensor and very precise navigation, they are capable of producing unprecedented images of the seafloor. This technology was used in December 1997 to map the East and West Flower Gardens and Stetson Banks, Gulf of Mexico. The results from this survey provide the most accurate maps of these areas yet produced and reveal features at submeter resolution never mapped in these areas before. The digital data provide a database that should become the fundamental base maps for all subsequent work in this recently established National Marine Sanctuary.

Signal processing, sensor fusion, and target recognition; Proceedings of the Meeting, Orlando, FL, Apr. 20-22, 1992

Science.gov (United States)

Libby, Vibeke; Kadar, Ivan

Consideration is given to a multiordered mapping technique for target prioritization, a neural network approach to multiple-target-tracking problems, a multisensor fusion algorithm for multitarget multibackground classification, deconvolutiom of multiple images of the same object, neural networks and genetic algorithms for combinatorial optimization of sensor data fusion, classification of atmospheric acoustic signals from fixed-wing aircraft, and an optics approach to sensor fusion for target recognition. Also treated are a zoom lens for automatic target recognition, a hybrid model for the analysis of radar sensors, an innovative test bed for developing and assessing air-to-air noncooperative target identification algorithms, SAR imagery scene segmentation using fractal processing, sonar feature-based bandwidth compression, laboratory experiments for a new sonar system, computational algorithms for discrete transform using fixed-size filter matrices, and pattern recognition for power systems.

On the Sediment Dynamics in a Tidally Energetic Channel: The Inner Sound, Northern Scotland

Directory of Open Access Journals (Sweden)

Jason McIlvenny

2016-04-01

Full Text Available Sediment banks within a fast-flowing tidal channel, the Inner Sound in the Pentland Firth, were mapped using multi-frequency side-scan sonar. This novel technique provides a new tool for seabed sediment and benthic habitat mapping. The sonar data are supplemented by sediment grab and ROV videos. The combined data provide detailed maps of persistent sand and shell banks present in the Sound despite the high energy environment. Acoustic Doppler Current Profiler (ADCP data and numerical model predictions were used to understand the hydrodynamics of the system. By combining the hydrodynamics and sediment distribution data, we explain the sediment dynamics in the area. Sediment particle shape and density, coupled with persistent features of the hydrodynamics, are the key factors in the distribution of sediment within the channel. Implications for tidal energy development planned for the Sound are discussed.

A man-made object detection for underwater TV

Science.gov (United States)

Cheng, Binbin; Wang, Wenwu; Chen, Yao

2018-03-01

It is a great challenging task to complete an automatic search of objects underwater. Usually the forward looking sonar is used to find the target, and then the initial identification of the target is completed by the side-scan sonar, and finally the confirmation of the target is accomplished by underwater TV. This paper presents an efficient method for automatic extraction of man-made sensitive targets in underwater TV. Firstly, the image of underwater TV is simplified with taking full advantage of the prior knowledge of the target and the background; then template matching technology is used for target detection; finally the target is confirmed by extracting parallel lines on the target contour. The algorithm is formulated for real-time execution on limited-memory commercial-of-the-shelf platforms and is capable of detection objects in underwater TV.

EX1203: Florida Escarpment and Straits Exploration on NOAA Ship Okeanos Explorer between 20120505 and 20120523

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — EX1203 of NOAA Ship Okeanos Explorer (EX) will run its Kongsberg EM302 multibeam sonar survey system 24 hours per day with periodic XBT casts for calibration. One to...

2004 Anne Arundel, Charles, Howard & St. Mary's Counties LiDAR Mapping

Data.gov (United States)

Federal Emergency Management Agency, Department of Homeland Security — Light Detection and Ranging (LIDAR) is a method of locating objects on the ground using aerial-borne equipment. It is similar to RADAR or SONAR in that the two-way...

2005 Maryland Department of Natural Resources LiDAR: Cecil County

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Light Detection and Ranging (LIDAR) is a method of locating objects on the ground using aerial-borne equipment. It is similar to RADAR or SONAR in that the two-way...

2004 Maryland Department of Natural Resources LiDAR: Anne Arundel, Charles, Howard and St. Mary's Counties

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Light Detection and Ranging (LIDAR) is a method of locating objects on the ground using aerial-borne equipment. It is similar to RADAR or SONAR in that the two-way...

Principles of underwater sound

National Research Council Canada - National Science Library

Urick, Robert J

1983-01-01

... the immediately useful help they need for sonar problem solving. Its coverage is broad-ranging from the basic concepts of sound in the sea to making performance predictions in such applications as depth sounding, fish finding, and submarine detection...

Automated Change Detection for Synthetic Aperture Sonar

Science.gov (United States)

2014-01-01

alerting to the presence of an acoustically chameleonic object. While the utility of exploiting changes in signal phase degrades over time, with time...pp. 643–656, October 2003. [7] D. Brie, M. Tomczak, H. Oehlmann, and A. Richard, “Gear crack detection by adaptive amplitude and phase demodulation

Mid-Frequency Sonar Interactions with Beaked Whales

Science.gov (United States)

2011-06-30

et al. 2006), in the Bahamas and Madeira in 2000 (NOAA 2001, Cox et al. 2006), and in the Canary Islands in 2002 (Proceed. ECS 2004). Cuvier’s beaked...acoustic testing strand whales?" Nature 392. 29 (1998). L. Freitas, "The stranding of three Cuvier’s beaked whales Ziphius caviostris in Madeira ... Madeira , 1999-2002," Woods Hole Oceanographic Institution Technical Report. WHOI-2005- 09, 38 pp. (2005). Available online at http://www.whoi.edu

Acoustically-Equipped Ocean Gliders for Environmental and Oceanographic Research

Science.gov (United States)

2015-09-30

operations, including use of tactical sonars, have been linked to marine mammal strandings and fatalities ( Barlow and Gisiner, 2006), particularly of...REFERENCES Barlow , J., and R. Gisiner. 2006. Mitigating, monitoring, and assessing the effects of anthropogenic sound on beaked whales. J

2003 Maryland Department of Natural Resources LiDAR: Dorchester, Somerset, Talbot,and Wicomico Counties, with portions of Caroline, Kent and Queen Anne's Counties

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Light Detection and Ranging (LiDAR) is a method of locating objects on the ground using aerial-borne equipment. It is similar to RADAR or SONAR in that the two-way...

CRED Gridded Bathymetry of the 1955 Eruption Site and Seamount (100-022) in the Northwestern Hawaiian Islands

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — File 100-022b is a 60-m ASCII grid of depth data collected near 1955 Eruption Site multibeam bathymetry data from a SeaBeam 210 sonar aboard the R/V...

2002 Maryland Department of Natural Resources LiDAR: Worcester County

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Light Detection and Ranging (LiDAR) is a method of locating objects on the ground using aerial-borne equipment. It is similar to RADAR or SONAR in that the two-way...

Okeanos Explorer (EX1607): CAPSTONE Wake Island PRI MNM (Mapping)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Operations will include 24 hour/day mapping operations using the ship’s deep water mapping systems (Kongsberg EM302 multibeam sonar, EK60 split-beam fisheries...

A fast algorithm for the computation of incoherent propagation loss for variable water depth : A validation study

NARCIS (Netherlands)

Sertlek, H.O.; Ainslie, M.A.

2014-01-01

Accurate and fast estimation of propagation loss (PL) is needed for simulations of sonar or acoustic communication performance, and for environmental risk assessment. Accurate calculation of PL in range dependent and lossy waveguides can require computationally expensive wave theory techniques . In

Survey and assessment of post volcanic activities of a young caldera lake, Lake Cuicocha, Ecuador

Directory of Open Access Journals (Sweden)

G. Gunkel

2009-05-01

Full Text Available Cuicocha is a young volcano adjacent to the inactive Pleistocene Cotacachi volcano complex, located in the western cordilleras of the Ecuadorian Andes. A series of eruptions with intensive ash emission and collapse of the caldera occurred around 4500–3000 y BP. A crater 3.2 km in diameter and a maximum depth of 450 m was formed. Further eruptions of the volcano occurred 1300 y BP and formed four smaller domes within the caldera. Over the last few hundred years, a caldera lake has developed, with a maximum depth of 148 m. The lake water is characterized by sodium carbonate with elevated concentrations of manganese, calcium and chloride. Nowadays, an emission of gases, mainly CO₂, and an input of warm spring water occur in Lake Cuicocha. The zone of high activity is in the western basin of the lake at a depth of 78 m, and continuous gas emissions with sediment resuspension were observed using sonar. In the hypolimnion of the lake, CO₂ accumulation occurs up to 0.2% saturation, but the risk of a limnic eruption can be excluded at present. The lake possesses monomictic stratification behaviour, and during overturn an intensive gas exchange with the atmosphere occurs. Investigations concerning the sedimentation processes of the lake suggest only a thin sediment layer of up to 10–20 cm in the deeper lake basin; in the western bay, in the area of gas emissions, the lake bottom is partly depleted of sediment in the form of holes, and no lake colmation exists. Decreases in the lake water level of about 30 cm y⁻¹ indicate a percolation of water into fractures and fissures of the volcano, triggered by a nearby earthquake in 1987.

EX1201: Ship Shakedown and Patch Tests on NOAA Ship Okeanos Explorer between 20100214 and 20120223

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — EX1201 is the 2012 shakedown mission of NOAA ship Okeanos Explorer (EX) and will perform system patch tests of the vessel’s Kongsberg EM302 multibeam sonar....

Timing matters

DEFF Research Database (Denmark)

Kothari, Ninad B.; Wohlgemuth, Melville J.; Hulgard, Katrine

2014-01-01

To successfully negotiate a cluttered environment, an echolocating bat must control the timing of motor behaviors in response to dynamic sensory information. Here we detail the big brown bat's adaptive temporal control over sonar call production for tracking prey, moving predictably or unpredicta...

Disturbance-specific social responses in long-finned pilot whales, Globicephala melas

NARCIS (Netherlands)

Visser, F.; Curé, C.; Kvadsheim, P.H.; Lam, F.P.A.; Tyack, P.L.; Miller, P.J.O.

2016-01-01

Social interactions among animals can influence their response to disturbance. We investigated responses of long-finned pilot whales to killer whale sound playbacks and two anthropogenic sources of disturbance: Tagging effort and naval sonar exposure. The acoustic scene and diving behaviour of

30 CFR 280.51 - What types of geophysical data and information must I submit to MMS?

Science.gov (United States)

2010-07-01

..., shallow and deep subbottom profiles, bathymetry, sidescan sonar, gravity and magnetic surveys, and special... and of a quality suitable for processing; (c) Processed geophysical information derived from seismic... interpretive evaluation, reflecting state-of-the-art processing techniques; and (d) Other geophysical data...

MP3 - A Meteorology and Physical Properties Package for Titan Air-Sea Studies

Science.gov (United States)

Lorenz, R. D.; Stofan, E.; Lunine, J. I.; Zarnecki, J. C.; Harri, A.-M.; Karkoschka, E.; Newman, C. E.; Bierhaus, E. B.; Clark, B. C.; Yelland, M.; Leese, M. R.; Boldt, J.; Darlington, E.; Neish, C. D.; Sotzen, K.; Arvelo, J.; Rasbach, C.; Kretsch, W.; Strohbehn, K.; Grey, M.; Mann, J.; Zimmerman, H.; Reed, C.

2012-10-01

MP3 is a sensor suite for the proposed Titan Mare Explorer (TiME) Discovery mission to Ligeia Mare. MP3 will measure temperatures, and wind velocity, methane humidity, and pressure, as well as sea turbidity, dielectric properties, and depth via sonar.

CRED Gridded Bathymetry of Nihoa Island and transit to Kauai (100-026) in the Northwestern Hawaiian Islands

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — File 100-026b is a 60-m ASCII grid of depth data collected near Nihoa multibeam bathymetry data from a SeaBeam 210 sonar aboard the R/V Kai'imikai-O-Kanaloa...

CRED Gridded Bathymetry of St. Rogatien and Brooks Banks (100-018) in the Northwestern Hawaiian Islands

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — File 100-018b is a 60-m ASCII grid of depth data collected near St. Rogatien multibeam bathymetry data from a SeaBeam 210 sonar aboard the R/V Kai'imikai-O-Kanaloa...

Marine archaeological explorations of Tranquebar-Poompuhar region on Tamil Nadu coast

Digital Repository Service at National Institute of Oceanography (India)

Rao, S.R.

-scan sonar and magnetic survey showed certain features in 10-11 m depth opposite Masalamani Temple and further north opposite Chinnavanagiri. To the south of Tranquebar a feature of the shape of a boat has been registered. Terracotta ring wells were found...

Synthetic aperture ultrasound Fourier beamformation using virtual sources

DEFF Research Database (Denmark)

Moghimirad, Elahe; Villagómez Hoyos, Carlos Armando; Mahloojifar, Ali

2016-01-01

An efficient Fourier beamformation algorithm is presented for multistatic synthetic aperture ultrasound imaging using virtual sources (FBV). The concept is based on the frequency domain wavenumber algorithm from radar and sonar and is extended to a multi-element transmit/receive configuration using...

Propagation loss model comparisons on selected scenarios from the Weston memorial workshop

NARCIS (Netherlands)

Sertlek, H.O.; Ainslie, M.A.

2013-01-01

The accurate and stable calculation of underwater acoustic propagation is needed for applications such as sonar performance prediction, noise mapping and acoustic communication. In this work, some widely used acoustic propagation models, based on different methods such as normal mode, ray tracing,

Screening for subtle chromosomal rearrangements in an Egyptian ...

African Journals Online (AJOL)

Rabah M. Shawky

ing, high resolution banding (HRB), and fluorescent in situ hybridization (FISH) technique with appropriate probes were carried out ... Shams University. The Egyptian Journal of Medical Human Genetics www.ejmhg.eg.net ... (to exclude aminoacidopathies), and pelvi-abdominal sonar and echocardiography for detection of.

Combining Cluster Analysis and Small Unmanned Aerial Systems (sUAS) for Accurate and Low-cost Bathymetric Surveying

Science.gov (United States)

Maples, B. L.; Alvarez, L. V.; Moreno, H. A.; Chilson, P. B.; Segales, A.

2017-12-01

Given that classical in-situ direct surveying for geomorphological subsurface information in rivers is time-consuming, labor-intensive, costly, and often involves high-risk activities, it is obvious that non-intrusive technologies, like UAS-based, LIDAR-based remote sensing, have a promising potential and benefits in terms of efficient and accurate measurement of channel topography over large areas within a short time; therefore, a tremendous amount of attention has been paid to the development of these techniques. Over the past two decades, efforts have been undertaken to develop a specialized technique that can penetrate the water body and detect the channel bed to derive river and coastal bathymetry. In this research, we develop a low-cost effective technique for water body bathymetry. With the use of a sUAS and a light-weight sonar, the bathymetry and volume of a small reservoir have been surveyed. The sUAS surveying approach is conducted under low altitudes (2 meters from the water) using the sUAS to tow a small boat with the sonar attached. A cluster analysis is conducted to optimize the sUAS data collection and minimize the standard deviation created by under-sampling in areas of highly variable bathymetry, so measurements are densified in regions featured by steep slopes and drastic changes in the reservoir bed. This technique provides flexibility, efficiency, and free-risk to humans while obtaining high-quality information. The irregularly-spaced bathymetric survey is then interpolated using unstructured Triangular Irregular Network (TIN)-based maps to avoid re-gridding or re-sampling issues.

Fish passage hydroelectric power plant Linne, Netherlands. Didson measurements; Vispassage waterkrachtcentrale Linne. Didson metingen

Energy Technology Data Exchange (ETDEWEB)

Van Keeken, O.A.; Griffioen, A.B. [Institute for Marine Resources and Ecosystem Studies IMARES, Wageningen UR, IJmuiden (Netherlands)

2011-11-15

The hydroelectric power plant in the Dutch Maas River near Linne has a fish deflection and passage system. For this study, two evenings in the months of August and September 2011 were dedicated to examining the extent to which fish approached and used the fish passage system. To establish the swimming behavior of the fish, a high-resolution sonar (DIDSON) was used, which generates moving images of fish in turbid waters, to study their behavior. [Dutch] Bij de waterkrachtcentrale in de Maas bij Linne is een visafweer- en geleidingssysteem aangelegd. In deze studie werd op twee avonden verdeeld over de maanden augustus en september 2011 gekeken in hoeverre vissen het visgeleidingssysteem benaderden en gebruikten. Voor het vaststellen van het zwemgedrag van de vissen is gebruik gemaakt van de DIDSON, een hoge resolutie sonar waarmee bewegende beelden kunnen worden gemaakt van vis in troebel water om het gedrag te bestuderen.

Directionality of nose-emitted echolocation calls from bats without a nose-leaf (Plecotus auritus)

DEFF Research Database (Denmark)

Jakobsen, Lasse; Hallam, John; Moss, Cynthia F

2018-01-01

All echolocating bats and whales measured to date emit a directional bio-sonar beam that affords them a number of advantages over an omni-directional beam, i.e. reduced clutter, increased source level and inherent directional information. In this study we investigated the importance...... of a directional sound emission for navigation through echolocation by measuring the sonar beam of brown long-eared bats, Plecotus auritusP. auritus emits sound through the nostrils but has no external appendages to readily facility a directional sound emission as found in most nose emitters. The study shows...... that P. auritus, despite the lack of an external focusing apparatus, emits a directional echolocation beam (Directivity index=13 dB) and that the beam is more directional vertically (-6 dB angle at 22°) than horizontally (-6dB angle at 35°). Using a simple numerical model we find that the recorded...

Auditory opportunity and visual constraint enabled the evolution of echolocation in bats.

Science.gov (United States)

Thiagavel, Jeneni; Cechetto, Clément; Santana, Sharlene E; Jakobsen, Lasse; Warrant, Eric J; Ratcliffe, John M

2018-01-08

Substantial evidence now supports the hypothesis that the common ancestor of bats was nocturnal and capable of both powered flight and laryngeal echolocation. This scenario entails a parallel sensory and biomechanical transition from a nonvolant, vision-reliant mammal to one capable of sonar and flight. Here we consider anatomical constraints and opportunities that led to a sonar rather than vision-based solution. We show that bats' common ancestor had eyes too small to allow for successful aerial hawking of flying insects at night, but an auditory brain design sufficient to afford echolocation. Further, we find that among extant predatory bats (all of which use laryngeal echolocation), those with putatively less sophisticated biosonar have relatively larger eyes than do more sophisticated echolocators. We contend that signs of ancient trade-offs between vision and echolocation persist today, and that non-echolocating, phytophagous pteropodid bats may retain some of the necessary foundations for biosonar.

Subsea surveying: a guide for oilmen. Deep-tow and digital techniques

Energy Technology Data Exchange (ETDEWEB)

Burns, F M

1977-05-01

Hydrodynamically stable tow fishes into which the acoustic energy source is mounted are examined. The advantages of deep-towed devices extends beyond the use of bottom and subbottom profiling systems. When used with side-scan sonar devices any small seabed relief or feature is enhanced by towing the sonar close to the seabed. The distortion of the records which is produced by observing slant ranges as opposed to the true range is also reduced. The use of marine magnetometers can greatly improve detection capabilities when searching for objects which produce some magnetic disturbance. The amplitude of this magnetic ''anomaly'' increases as the range between the magnetic sensor and the object is decreased. Areas where digital processing of data can be of significant value include navigational positioning (both of surface and sub-surface vessels); signal processing of seismic profiling data; and data presentation of all forms.

Anti-bat tiger moth sounds: Form and function

Directory of Open Access Journals (Sweden)

Aaron J. CORCORAN, William E. CONNER, Jesse R. BARBER

2010-06-01

Full Text Available The night sky is the venue of an ancient acoustic battle between echolocating bats and their insect prey. Many tiger moths (Lepidoptera: Arctiidae answer the attack calls of bats with a barrage of high frequency clicks. Some moth species use these clicks for acoustic aposematism and mimicry, and others for sonar jamming, however, most of the work on these defensive functions has been done on individual moth species. We here analyze the diversity of structure in tiger moth sounds from 26 species collected at three locations in North and South America. A principal components analysis of the anti-bat tiger moth sounds reveals that they vary markedly along three axes: (1 frequency, (2 duty cycle (sound production per unit time and frequency modulation, and (3 modulation cycle (clicks produced during flexion and relaxation of the sound producing tymbal structure. Tiger moth species appear to cluster into two distinct groups: one with low duty cycle and few clicks per modulation cycle that supports an acoustic aposematism function, and a second with high duty cycle and many clicks per modulation cycle that is consistent with a sonar jamming function. This is the first evidence from a community-level analysis to support multiple functions for tiger moth sounds. We also provide evidence supporting an evolutionary history for the development of these strategies. Furthermore, cross-correlation and spectrogram correlation measurements failed to support a “phantom echo” mechanism underlying sonar jamming, and instead point towards echo interference [Current Zoology 56 (3: 358–369, 2010].

A Bird's-eye View with X-ray Vision: Remote-sensing tools to Monitor Reach-scale Response to Dam Removal on the Elwha River

Science.gov (United States)

Ritchie, A. C.

2012-12-01

Repeat digital surface models, orthoimagery and sidescan sonar data are being generated to monitor river response to the largest dam removal and controlled sediment release in history on the Elwha River, on the Olympic Peninsula in Washington State. These products are generated using low-cost readily-available tools to collect data at a spatial and temporal scale that provides important insight into effects of base-level change, sediment release, and discrete hydrologic events on erosion of reservoir sediments, downstream sediment transport, and channel evolution above and below the dam sites. In combination, these products provide a view above and below the water surface to changes in sediment composition and morphology that other methods cannot capture at this spatial scale and both spatial and temporal resolution. Orthoimagery is developed from still images collected with a plane-mounted point-and-shoot camera using customized firmware from the open-source Canon Hack Development Kit (CHDK) with a total hardware cost of about $300 USD. Images are processed using structure-from-motion algorithms. Several software options are available. Sonar data are collected from a raft-mounted platform using a high-resolution 990 KHz Starfish sidescan sonar, with a water-resistant topside enclosure holding top-side electronics. A steerable pole-mount was developed for this application to allow the sidescan to to remain oriented in the direction of motion-over-ground.; Surface reconstruction from aerial images collected during Elwha dam removal project. ; bedforms near Elwha Sediment Treatment Plant from sediment released from Lake Aldwell, surveyed 12 July 2012.

Evaluating habitat associations of a fish assemblage at multiple spatial scales in a minimally disturbed stream using low-cost remote sensing

Science.gov (United States)

Cheek, Brandon D.; Grabowski, Timothy B.; Bean, Preston T.; Groeschel, Jillian R.; Magnelia, Stephan J.

2016-01-01

Habitat heterogeneity at multiple scales is a major factor affecting fish assemblage structure. However, assessments that examine these relationships at multiple scales concurrently are lacking. The lack of assessments at these scales is a critical gap in understanding as conservation and restoration efforts typically work at these levels.A combination of low-cost side-scan sonar surveys, aerial imagery using an unmanned aerial vehicle, and fish collections were used to evaluate the relationship between physicochemical and landscape variables at various spatial scales (e.g. micro-mesohabitat, mesohabitat, channel unit, stream reach) and stream–fish assemblage structure and habitat associations in the South Llano River, a spring-fed second-order stream on the Edwards Plateau in central Texas during 2012–2013.Low-cost side-scan sonar surveys have not typically been used to generate data for riverscape assessments of assemblage structure, thus the secondary objective was to assess the efficacy of this approach.The finest spatial scale (micro-mesohabitat) and the intermediate scale (channel unit) had the greatest explanatory power for variation in fish assemblage structure.Many of the fish endemic to the Edwards Plateau showed similar associations with physicochemical and landscape variables suggesting that conservation and restoration actions targeting a single endemic species may provide benefits to a large proportion of the endemic species in this system.Low-cost side-scan sonar proved to be a cost-effective means of acquiring information on the habitat availability of the entire river length and allowed the assessment of how a full suite of riverscape-level variables influenced local fish assemblage structure.

Multibeam bathymetry and CTD measurements in two fjord systems in southeastern Greenland

DEFF Research Database (Denmark)

Kjeldsen, Kristian Kjellerup; Weinrebe, Reimer Wilhelm; Bendtsen, Jørgen

2017-01-01

We present bathymetry and hydrological observations collected in the summer of 2014 from two fjordsystems in southeastern Greenland with a multibeam sonar system. Our results provide a detailed bathymetricmap of the fjord complex around the island of Skjoldungen in Skjoldungen Fjord and the outer...

Threshold received sound pressure levels of single 1-2 kHz and 6-7 kHz up-sweeps and down-sweeps causing startle responses in a harbor porpoise (Phocoena phocoena)

NARCIS (Netherlands)

Kastelein, R.A.; Steen, N.; Gransier, R.; Wensveen, P.J.; Jong, C.A.F. de

2012-01-01

Mid-frequency and low-frequency sonar systems produce frequency-modulated sweeps which may affect harbor porpoises. To study the effect of sweeps on behavioral responses (specifically startle responses, which we define as sudden changes in swimming speed and/or direction), a harbor porpoise in a

Mud volcanos and mud domes of the central Mediterranean Ridge: near bottom and in situ observations

NARCIS (Netherlands)

Huguen, C.; Mascle, J.; Woodside, J.M.; Zitter, T.A.C.; Foucher, J.-P.

2005-01-01

The first high-resolution mapping of mud volcanoes and mud domes of the Central Mediterranean Ridge (Eastern Mediterranean) presented here is based on successive in situ observations from the Nautile submersible [MEDINAUT (1998) and NAUTINIL (2003) surveys] and near-bottom side-scan sonar data

Quantification of methane bubbles in shallow freshwaters using horizontal hydroacoustical observations

Czech Academy of Sciences Publication Activity Database

Frouzová, Jaroslava; Tušer, Michal; Stanovský, Petr

2015-01-01

Roč. 13, č. 11 (2015), s. 609-616 ISSN 1541-5856 R&D Projects: GA ČR(CZ) GAP504/12/1186 Institutional support: RVO:60077344 ; RVO:67985858 Keywords : methane ebullition * freshwaters * sonar Subject RIV: DA - Hydrology ; Limnology Impact factor: 2.008, year: 2015

Efficient calculation of broadband acoustic scattering from a partially, obliquely buried cylinder

NARCIS (Netherlands)

Nijhof, M.J.J.; Espana, A.; Williams, K.

2013-01-01

An efficient model for the Target In Environment Response (TIER) of buried/half buried, mine-like objects and UXOs is essential for the development and training of automatic target detection and classification methods and for use in sonar performance prediction models. For instance, to investigate

Classification of underwater target echoes based on auditory perception characteristics

Science.gov (United States)

Li, Xiukun; Meng, Xiangxia; Liu, Hang; Liu, Mingye

2014-06-01

In underwater target detection, the bottom reverberation has some of the same properties as the target echo, which has a great impact on the performance. It is essential to study the difference between target echo and reverberation. In this paper, based on the unique advantage of human listening ability on objects distinction, the Gammatone filter is taken as the auditory model. In addition, time-frequency perception features and auditory spectral features are extracted for active sonar target echo and bottom reverberation separation. The features of the experimental data have good concentration characteristics in the same class and have a large amount of differences between different classes, which shows that this method can effectively distinguish between the target echo and reverberation.

Coastal morphology and dynamics of two beaches of Favignana

International Nuclear Information System (INIS)

Pasanisi, Francesco; Tebano, Carlo; Grauso, Sergio

2015-01-01

Results of an investigation on the coastal morphology and dynamics of two pocket beaches of Favignana, Cala Azzurra and Lido Burrone, are presented. Four detailed hydrographic surveys were performed using multibeam echo sounder with sidescan sonar and differential marine GPS. Surveys were repeated in different periods following the same navigation project. Moreover, incident wave climate and coastal hydrodynamics were investigated using state-of-the-art numerical models. Results of in-situ activities indicate little bathymetric variations among different surveys and suggest a substantial stability of submerged beach profiles limited to surveyed area. Slightly greater bathymetric changes and a generally more intense coastal dynamics were observed at Cala Azzurra compared to Lido Burrone. Simulations of wave propagation and nearshore circulation currents provided results consistent with field observations [it

Comparison of Shallow Survey 2012 Multibeam Datasets

Science.gov (United States)

Ramirez, T. M.

2012-12-01

The purpose of the Shallow Survey common dataset is a comparison of the different technologies utilized for data acquisition in the shallow survey marine environment. The common dataset consists of a series of surveys conducted over a common area of seabed using a variety of systems. It provides equipment manufacturers the opportunity to showcase their latest systems while giving hydrographic researchers and scientists a chance to test their latest algorithms on the dataset so that rigorous comparisons can be made. Five companies collected data for the Common Dataset in the Wellington Harbor area in New Zealand between May 2010 and May 2011; including Kongsberg, Reson, R2Sonic, GeoAcoustics, and Applied Acoustics. The Wellington harbor and surrounding coastal area was selected since it has a number of well-defined features, including the HMNZS South Seas and HMNZS Wellington wrecks, an armored seawall constructed of Tetrapods and Akmons, aquifers, wharves and marinas. The seabed inside the harbor basin is largely fine-grained sediment, with gravel and reefs around the coast. The area outside the harbor on the southern coast is an active environment, with moving sand and exposed reefs. A marine reserve is also in this area. For consistency between datasets, the coastal research vessel R/V Ikatere and crew were used for all surveys conducted for the common dataset. Using Triton's Perspective processing software multibeam datasets collected for the Shallow Survey were processed for detail analysis. Datasets from each sonar manufacturer were processed using the CUBE algorithm developed by the Center for Coastal and Ocean Mapping/Joint Hydrographic Center (CCOM/JHC). Each dataset was gridded at 0.5 and 1.0 meter resolutions for cross comparison and compliance with International Hydrographic Organization (IHO) requirements. Detailed comparisons were made of equipment specifications (transmit frequency, number of beams, beam width), data density, total uncertainty, and

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African Journals Online (AJOL)

A localization test with the triplet ... Les recherches ont déjà montré que le retour sonar du type temps de vol monaural est caractérisé par une marge ... Un test de localisation avec ce triplet ...... Kenneth D. Harris and Michael Reece (1998).

Computational Solutions for Today’s Navy: New Methods are Being Employed to Meet the Navy’s Changing Software-Development Environment

Science.gov (United States)

2008-03-01

software- development environment. ▶ Frank W. Bentrem, Ph.D., John T. Sample, Ph.D., and Michael M. Harris he Naval Research Labor - atory (NRL) is the...sonars (Through-the-Sensor technology), supercomputer generated numer- ical models, and historical/ clima - tological databases. It uses a vari- ety of

Acoustic study of fish and invertebrate behavior in a tropical reservoir

NARCIS (Netherlands)

Prchalová, M.; Drastík, V.; Kubeka, J.; Sricharoendham, B.; Schiemer, F.; Vijverberg, J.

2003-01-01

The fish and invertebrate behavior of the Ubol Ratana Reservoir, Thailand, were monitored using up- and downlooking split beam sonar located at a fixed location. In the same area and period, ichthyoplankton nets and multimesh gillnets were used. The bulk of targets, recorded by acoustics and direct

A wideband connection to sperm whales: A fiber-optic, deep-sea hydrophone array

DEFF Research Database (Denmark)

Heerfordt, Anders; Møhl, Bertel; Wahlberg, Magnus

2007-01-01

A 10-element, 950 m long, vertical hydrophone array based on fiber-optic data transmission has been developed primarily for studying the beam pattern from deep diving cetaceans emitting sonar pulses. The array elements have a configurable sampling rate and resolution with a maximum signal bandwidth...

Fourier beamformation of multistatic synthetic aperture ultrasound imaging

DEFF Research Database (Denmark)

Moghimirad, Elahe; Villagómez Hoyos, Carlos Armando; Mahloojifar, Ali

2015-01-01

A new Fourier beamformation (FB) algorithm is presented for multistatic synthetic aperture ultrasound imaging. It can reduce the number of computations by a factor of 20 compared to conventional Delay-and-Sum (DAS) beamformers. The concept is based on the wavenumber algorithm from radar and sonar...

Beta Testing of Persistent Passive Acoustic Monitors

Science.gov (United States)

2012-10-01

three platforms provide the capability to work over a wide range of spatial and temporal scales. Hardware and software integration of the DMONs in...closely with Richard M. Ead (Sensors and Sonar Systems Department, Naval Undersea Warfare Center, NUWC Code 1535), Ted Ioannides (PS 4013) and Dave

Defense Industrial Base Capabilities Study: Battlespace Awareness

Science.gov (United States)

2004-01-01

not production capacity or workforce issues. It considers the best capabilities in both the domestic and foreign components of the industrial base...www.maliburesearch.com Ground Penetrating Radar MARIMATECH 1989 Aarhus, Denmark n.a. n.a. www.marimatech.com Sonar Maser Technology (NZ) Ltd. 1983 Auckland , New

Geophysical and sampling data from the inner continental shelf: Duxbury to Hull, Massachusetts

Science.gov (United States)

Barnhardt, Walter A.; Ackerman, Seth D.; Andrews, Brian D.; Baldwin, Wayne E.

2010-01-01

The U.S. Geological Survey (USGS) and the Massachusetts Office of Coastal Zone Management (CZM) have cooperated to map approximately 200 km² of the Massachusetts inner continental shelf between Duxbury and Hull. This report contains geophysical and geological data collected by the USGS on three cruises between 2006 and 2007. These USGS data are supplemented with a National Oceanic and Atmospheric Administration (NOAA) hydrographic survey conducted in 2003 to update navigation charts. The geophysical data include (1) swath bathymetry from interferometric sonar and multibeam echosounders, (2) acoustic backscatter from sidescan sonar and multibeam echosounders, and (3) subsurface stratigraphy and structure from seismic-reflection profilers. The geological data include sediment samples, seafloor photographs, and bottom videos. These spatial data support research on the influence sea-level change and sediment supply have on coastal evolution, and on efforts to understand the type, distribution, and quality of subtidal marine habitats in the Massachusetts coastal ocean.

An Improved Sequential Initiation Method for Multitarget Track in Clutter with Large Noise Measurement

Directory of Open Access Journals (Sweden)

Daxiong Ji

2014-01-01

Full Text Available This paper proposes an improved sequential method for underwater multiple objects tracks initiation in clutter, estimating the initial position for the trajectory. The underwater environment is complex and changeable, and the sonar data are not very ideal. When the detection distance is far, the error of measured data is also great. Besides that, the clutter has a grave effect on the tracks initiation. So it is hard to initialize a track and estimate the initial position. The new tracks initiation is that when at least six of ten points meet the requirements, then we determine that there is a new track and the initial states of the parameters are estimated by the linear least square method. Compared to the conventional tracks initiation methods, our method not only considers the kinematics information of targets, but also regards the error of the sonar sensors as an important element. Computer simulations confirm that the performance of our method is very nice.

Acoustic water bottom investigation with a remotely operated watercraft survey system

Science.gov (United States)

Yamasaki, Shintaro; Tabusa, Tomonori; Iwasaki, Shunsuke; Hiramatsu, Masahiro

2017-12-01

This paper describes a remotely operated investigation system developed by combining a modern leisure-use fish finder and an unmanned watercraft to survey water bottom topography and other data related to bottom materials. Current leisure-use fish finders have strong depth sounding capabilities and can provide precise sonar images and bathymetric information. Because these sonar instruments are lightweight and small, they can be used on unmanned small watercraft. With the developed system, an operator can direct the heading of an unmanned watercraft and monitor a PC display showing real-time positioning information through the use of onboard equipment and long-distance communication devices. Here, we explain how the system was developed and demonstrate the use of the system in an area of submerged woods in a lake. The system is low cost, easy to use, and mobile. It should be useful in surveying areas that have heretofore been hard to investigate, including remote, small, and shallow lakes, for example, volcanic and glacial lakes.

Surficial geology and benthic habitat of the German Bank seabed, Scotian Shelf, Canada

Science.gov (United States)

Todd, Brian J.; Kostylev, Vladimir E.

2011-01-01

To provide the scientific context for management of a newly opened scallop fishing ground, surficial geology and benthic habitats were mapped on German Bank on the southern Scotian Shelf off Atlantic Canada. To provide a seamless regional dataset, multibeam sonar surveys covered 5320 sqaure kilometres of the bank in water depths of 30–250 m and provided 5 m horizontal resolution bathymetry and backscatter strength. Geoscience data included high-resolution geophysical profiles (seismic reflection and sidescan sonar) and seabed sediment samples. Geological interpretation and is overlain in places by glacial and postglacial sediment. Biological data included seafloor video transects and photographs from which 127 taxa of visible megabenthos were identified. Trawl bycatch data were obtained from government annual research surveys. Statistical analysis of revealed that bedrock is exposed at the seafloor on much of German Bankthese two datasets and a suite of oceanographic environmental variables demonstrated that significantly different fauna exist on bedrock, glacial sediment and postglacial sediment.

Intercontinental Multi-Domain Monitoring for the LHC Optical Private Network

CERN Multimedia

CERN. Geneva

2012-01-01

The Large Hadron Collider (LHC) is currently running at CERN in Geneva, Switzerland. Physicists are using LHC to recreate the conditions just after the Big Bang, by colliding two beams of particles and heavy ions head-on at very high energy. The project is expected to generate 27 TB of raw data per day, plus 10 TB of "event summary data". This data is sent out from CERN to eleven Tier 1 academic institutions in Europe, Asia, and North America using a multi-gigabits Optical Private Network (OPN), the LHCOPN. Network monitoring on such complex network architecture to ensure robust and reliable operation is of crucial importance. The chosen approach for monitoring the OPN is based on the perfSONAR MDM framework (http://perfsonar.geant.net), which is designed for multi-domain monitoring environments. perfSONAR (www.perfsonar.net) is an infrastructure for performance monitoring data exchange between networks, making it easier to solve performance problems occurring between network measurement points interconne...

Development of an advanced intelligent robot navigation system

International Nuclear Information System (INIS)

Hai Quan Dai; Dalton, G.R.; Tulenko, J.; Crane, C.C. III

1992-01-01

As part of the US Department of Energy's Robotics for Advanced Reactors Project, the authors are in the process of assembling an advanced intelligent robotic navigation and control system based on previous work performed on this project in the areas of computer control, database access, graphical interfaces, shared data and computations, computer vision for positions determination, and sonar-based computer navigation systems. The system will feature three levels of goals: (1) high-level system for management of lower level functions to achieve specific functional goals; (2) intermediate level of goals such as position determination, obstacle avoidance, and discovering unexpected objects; and (3) other supplementary low-level functions such as reading and recording sonar or video camera data. In its current phase, the Cybermotion K2A mobile robot is not equipped with an onboard computer system, which will be included in the final phase. By that time, the onboard system will play important roles in vision processing and in robotic control communication

Auditory opportunity and visual constraint enabled the evolution of echolocation in bats

DEFF Research Database (Denmark)

Thiagavel, Jeneni; Cechetto, Clément; Santana, Sharlene E

2018-01-01

and flight. Here we consider anatomical constraints and opportunities that led to a sonar rather than vision-based solution. We show that bats' common ancestor had eyes too small to allow for successful aerial hawking of flying insects at night, but an auditory brain design sufficient to afford echolocation...

The Influence of Changing Sea Conditions on Shipping Noise, Including Effects of Wind, Fish and Climate Change

NARCIS (Netherlands)

Ainslie, M.A.; Jong, C.A.F. de

2011-01-01

Early human interest in ambient noise in the sea, especially during and after the Second World War, resulted from its effect on limiting the performance of military search sonar [Urick 1983]. While that interest continues, it is now accompanied by non-military uses of underwater sound, such as

Synthetic Aperture Beamforming in Ultrasound using Moving Arrays

DEFF Research Database (Denmark)

Andresen, Henrik

Medical ultrasound (US) is widely used because it allows cheap real-time imaging of soft tissue with no known side-effects or hazards to either patients or operating personnel. US has existed since the 1960s and was originally adapted from the concept of radar and sonar. The development...

76 FR 20257 - Taking and Importing Marine Mammals; U.S. Navy's Research, Development, Test, and Evaluation...

Science.gov (United States)

2011-04-12

... marine mammals (e.g., whale watching or dolphin watching boats), scientists have documented that animals... marine mammal(s) Wave height (in feet) Visibility Sonar source in use (y/n) Indication of whether animal...-AX11 Taking and Importing Marine Mammals; U.S. Navy's Research, Development, Test, and Evaluation...

Enhancing Tele-robotics with Immersive Virtual Reality

Science.gov (United States)

2017-11-03

The spheres displayed in the virtual environment represent the real-world readings from the robot in real-time from its LRF and sonar sensors. In...Inc., is comprised of an advanced graphics rendering engine, sound engine, and physics and animation engines. This game engine is capable of delivering

40 CFR 451.2 - General definitions.

Science.gov (United States)

2010-07-01

... program for the receiving waters into which a facility subject to this part discharges. (l) Pesticide means any substance defined as a “pesticide” in section 2(u) of the Federal Insecticide, Fungicide, and..., devices such as video cameras, digital scanning sonar, or upweller systems that allow facilities to...

Calculation of Head Related Transfer Functions of bats using the Boundary Element Method

DEFF Research Database (Denmark)

Juhl, Peter Møller; Cutanda Henriquez, Vicente; Vanderelst, Dieter

2009-01-01

Overskrift: ChiRoPing (Chiroptera, Robots, and Sonar) is an EU-funded research project aimed at understanding how bats use their echolocation perception ability and apply this knowledge to the design of new robotic senses. Four species of bats are selected for the study and models of their heads...

Project Report of Virtual Experiments in Marine Bioacoustics: Model Validation

Science.gov (United States)

2010-08-01

given initial velocity which starts the tissue " blobs " in opposing directions so that they collide and thereby produce an acoustic pressure wave. The...Atlantic bottlenose dolphin (Tursiops truncatus) in open waters. In: R. G. BUSNEL AND J. F. FISH (eds.). Animal Sonar Systems, pp. 251-282. Plenum

The Smallest R/V: A Small-scale Ocean Exploration Demonstration of Real-time Bathymetric Measurements

Science.gov (United States)

Howell, S. M.; Boston, B.; Maher, S. M.; Sleeper, J. D.; Togia, H.; Tree, J. P.

2014-12-01

In October 2013, graduate student members of the University of Hawaii Geophysical Society designed a small-scale model research vessel (R/V) that uses sonar to create 3D maps of a model seafloor in real-time. This pilot project was presented to the public at the School of Ocean and Earth Science and Technology's (SOEST) Biennial Open House weekend. An estimated 7,600 people attended the two-day event, including children and teachers from Hawaii's schools, home school students, community groups, families, and science enthusiasts. Our exhibit demonstrated real-time sonar mapping of a cardboard volcano using a toy size research vessel on a fixed 2D model ship track suspended above a model seafloor. Sound wave travel times were recorded using an unltrasonic emitter/receiver attached to an Arduino microcontroller platform, while the same system measured displacement along the ship track. This data was streamed through a USB connection to a PC running MatLab, where a 3D model was updated as the ship collected data. Our exhibit demonstrates the practical use of complicated concepts, like wave physics and data processing, in a way that even the youngest elementary students are able to understand. It provides an accessible avenue to learn about sonar mapping, and could easily be adapted to talk about bat and marine mammal echolocation by replacing the model ship and volcano. The exhibit received an overwhelmingly positive response from attendees, and has inspired the group to develop a more interactive model for future exhibitions, using multiple objects to be mapped that participants could arrange, and a more robust ship movement system that participants could operate.

Bathymetry & Geomorphology - A New Seafloor Mapping of the Israeli Exclusive Economic Zone

Science.gov (United States)

Tibor, G.; Hall, J. K.; Kanari, M.; Sade, R. A.; Sade, H.; Amit, G.; Gur-Arie, L.; Ketter, T.

2017-12-01

Recent extensive activities of oil and gas exploration and production companies in the Israeli Exclusive Economic Zone (EEZ) raised the need for an up-to-date baseline mapping of the seafloor to assist policy makers. The baseline mapping focused on bathymetry, geomorphology, geology, biodiversity, infauna and habitat in order to compile a sensitivity map for the Petroleum Commissioner in the Ministry of Energy in the bid for opening the sea to new natural gas and oil explorations. The Israeli EEZ covers an area of 25,950 sq. km. and reaches a maximum water depth of 2,100 m. It is located within the Levantine Basin, a zone of compression and strike-slip tectonics as Africa pushes into Eurasia. These forces operate on a half kilometer thick of Messinian evaporates and over a dozen kilometers of Pliocene and Pleistocene sediments to produce a complex seafloor morphology. The margin is cut by numerous slumps and canyons, while the basin is traversed by deep sea channels emptying into the moat around Eratosthenes Seamount farther north. The bathymetric and geomorphological mapping was done in three phases using Kongsberg and Elac multibeam sonars installed on different research vessels. The last phase (Aug.-Sept., 2016) covering depths from 1,400 to 2,100 m used the Kongsberg EM302 sonar installed on our new governmental research vessel Bat Galim. It has "state of the art" capabilities to map, sample and analyze the water column, seafloor and sub-bottom from water depths of 10m to 7,000 m. These mapping capabilities are unique in our region, the Eastern Mediterranean and the Red Sea, so we hope to promote research collaborations with our neighbors.

Geology and biology of the "Sticky Grounds," shelf-margin carbonate mounds, and mesophotic ecosystem in the eastern Gulf of Mexico

Science.gov (United States)

Locker, Stanley D.; Reed, John K.; Farrington, Stephanie; Harter, Stacey; Hine, Albert C.; Dunn, Shane

2016-01-01

Shelf-margin carbonate mounds in water depths of 116–135 m in the eastern Gulf of Mexico along the central west Florida shelf were investigated using swath bathymetry, side-scan sonar, sub-bottom imaging, rock dredging, and submersible dives. These enigmatic structures, known to fisherman as the “Sticky Grounds”, trend along slope, are 5–15 m in relief with base diameters of 5–30 m, and suggest widespread potential for mesophotic reef habitat along the west Florida outer continental shelf. Possible origins are sea-level lowstand coral patch reefs, oyster reefs, or perhaps more recent post-lowstand biohermal development. Rock dredging recovered bioeroded carbonate-rock facies comprised of bored and cemented bioclastics. Rock sample components included calcified worm tubes, pelagic sediment, and oysters normally restricted to brackish nearshore areas. Several reef sites were surveyed at the Sticky Grounds during a cruise in August 2010 with the R/V Seward Johnson using the Johnson-Sea-Link II submersible to ground truth the swath-sonar maps and to quantify and characterize the benthic habitats, benthic macrofauna, fish populations, and coral/sponge cover. This study characterizes for the first time this mesophotic reef ecosystem and associated fish populations, and analyzes the interrelationships of the fish assemblages, benthic habitats and invertebrate biota. These highly eroded rock mounds provide extensive hard-bottom habitat for reef invertebrate species as well as essential fish habitat for reef fish and commercially/recreationally important fish species. The extent and significance of associated living resources with these bottom types is particularly important in light of the 2010 Deepwater Horizon oil spill in the northeastern Gulf and the proximity of the Loop Current. Mapping the distribution of these mesophotic-depth ecosystems is important for quantifying essential fish habitat and describing benthic resources. These activities can improve

Cruise report; RV Coastal Surveyor Cruise C1-99; multibeam mapping of the Long Beach, California continental shelf; April 12 through May 19, 1999

Science.gov (United States)

Gardner, James V.; Hughes-Clarke, John E.; Mayer, Larry A.

1999-01-01

The greater Los Angeles area of California is home to more than 10 million people. This large population puts increased pressure on the adjacent offshore continental shelf and margin with activities such as ocean disposal for dredged spoils, explosive disposal, waste-water outfall, and commercial fishing. The increased utilization of the shelf and margin in this area has generated accelerated multi-disciplinary research efforts in all aspects of the environment of the coastal zone. Prior to 1996 there were no highly accurate base maps of the continental shelf and slope upon which the research activities could be located and monitored. In 1996, the United States Geological Survey (USGS) Pacific Seafloor Mapping Project began to address this problem by mapping the Santa Monica shelf and margin (Fig. 1) using a state-of-the-art, high-resolution multibeam sonar system (Gardner, et al., 1996; 1999). Additional seafloor mapping in 1998 provided coverage of the continental margin from south of Newport to the proximal San Pedro Basin northwest of Palos Verdes Peninsula (Gardner, et al., 1998) (Fig. 1). The mapping of the seafloor in the greater Los Angeles continental shelf and margin was completed with a 30-day mapping of the Long Beach shelf in April and May 1999, the subject of this report. The objective of Cruise C-1-99-SC was to completely map the broad continental shelf from the eastern end of the Palos Verdes Peninsula to the narrow shelf south of Newport Beach, from the break in slope at about 120-m isobath to the inner shelf at about the 10-m isobath. Mapping the Long Beach shelf was jointly funded by the U.S. Geological Survey and the County of Orange (CA) Sanitation District and was conducted under a Cooperative Agreement with the Ocean Mapping Group from the University of New Brunswick (OMG/UNB). The OMG/UNB contracted with C&C Technologies, Inc. of Lafayette, LA for use of the RV Coastal Surveyor and the latest evolution of high-resolution multibeam sonars, a

Seafloor Mapping: We've Come a Long Way - But Still Have Far to Go……

Science.gov (United States)

Mayer, L. A.

2017-12-01

Our ability to map the seafloor has changed radically over the past century. For thousands of years a weight at the end of a rope (or wire) - a lead line - provided the only means to measure depth. By the end of the Second World War, single beam echo sounders had been perfected to the extent that they became common on oceanographic and other vessels providing more rapid but laterally averaged (typically over a distance commensurate with the water depth) measurements of seafloor depths. Towards the end of the 20th Century - two great advances were made in seafloor mapping - the development of techniques to use satellite altimetry to predict seafloor bathymetry and the evolution of multibeam sonar technology from classified military applications to the academic and commercial communities. Satellite-altimetry derived bathymetry provides an unprecedented view of seafloor topography and tremendous insight into tectonic-scale processes but is limited in achievable resolution. Multibeam sonars offer the potential of extremely high-resolution (a function of array size, beam footprint, and water depth), but are typically deployed from manned surface vessels that cover limited amount of seafloor at a relatively high daily cost. We have the technology to map the entire world ocean with multibeam sonar but It has been estimated that to map the world ocean deeper than about 150m (shallow water is very time-consuming and expensive because the coverage swath width is typically 3-5 times water) would take approximately 200 ship years and cost on the order of 3 billion dollars. We have demonstrated our willingness to spend billions to map other planets (e.g. Mars and the Moon) but for some reason, not our own. Recently, however, there has been growing momentum to see the entire world ocean mapped. The Nippon Foundation and GEBCO have recently announced the Seabed 2030 project with a goal of facilitating the mapping of the world ocean by 2030 and international agreements like The

High resolution hybrid optical and acoustic sea floor maps (Invited)

Science.gov (United States)

Roman, C.; Inglis, G.

2013-12-01

This abstract presents a method for creating hybrid optical and acoustic sea floor reconstructions at centimeter scale grid resolutions with robotic vehicles. Multibeam sonar and stereo vision are two common sensing modalities with complementary strengths that are well suited for data fusion. We have recently developed an automated two stage pipeline to create such maps. The steps can be broken down as navigation refinement and map construction. During navigation refinement a graph-based optimization algorithm is used to align 3D point clouds created with both the multibeam sonar and stereo cameras. The process combats the typical growth in navigation error that has a detrimental affect on map fidelity and typically introduces artifacts at small grid sizes. During this process we are able to automatically register local point clouds created by each sensor to themselves and to each other where they overlap in a survey pattern. The process also estimates the sensor offsets, such as heading, pitch and roll, that describe how each sensor is mounted to the vehicle. The end results of the navigation step is a refined vehicle trajectory that ensures the points clouds from each sensor are consistently aligned, and the individual sensor offsets. In the mapping step, grid cells in the map are selectively populated by choosing data points from each sensor in an automated manner. The selection process is designed to pick points that preserve the best characteristics of each sensor and honor some specific map quality criteria to reduce outliers and ghosting. In general, the algorithm selects dense 3D stereo points in areas of high texture and point density. In areas where the stereo vision is poor, such as in a scene with low contrast or texture, multibeam sonar points are inserted in the map. This process is automated and results in a hybrid map populated with data from both sensors. Additional cross modality checks are made to reject outliers in a robust manner. The final

SAKAMATA : A tool to avoid whale strandings

NARCIS (Netherlands)

Benders, F.P.A.; Beerens, S.P.; Verboom, W.C.

2004-01-01

World-wide a concern exists about the influence of man-made noise on marine life, and particularly of high power sonar. Most concern lies with marine mammals that use acoustics for hunting, communication and/or navigation. This concern is fed by recent strandings of whales that could be related to

SAKAMATA: The Ideas and Algorithms Behind it

NARCIS (Netherlands)

Benders, F.P.A.; Beerens, S.P.; Verboom, W.C.

2004-01-01

World-wide a concern exists about the influence of man-made noise, and particularly of high power sonar, on marine life and divers in the sea. Most concern lies with marine mammals that use acoustics for hunting, communication and/or navigation. This concern is fed by recent strandings of whales

SAKAMATA : A tool to avoid whale strandings

NARCIS (Netherlands)

Benders, F.P.A.; Beerens, S.P.; Verboom, W.C.

2002-01-01

World-wide a concern exists about the influence of man-made noise on marine life, and particularly of high power sonar. Most concern lies with marine mammals that use acoustics for hunting, communication and/or navigation. This concern is fed by recent strandings of whales that could be related to

An Unfinished Job? The Effect of Subject Choice and Family Formation Processes on Labour Market Outcomes of Young Men and Women

Science.gov (United States)

Duquet, Nils; Glorieux, Ignace; Laurijssen, Ilse; Van Dorsselaer, Yolis

2010-01-01

Despite their generally higher educational attainment, young women are characterised by lower labour market positions than men in Belgium. Using regression and decomposition analyses on data from the longitudinal SONAR survey on the transition from school to work, we examine to what extent subject choice and processes of family formation can…

Acoustic scanning of natural scenes by echolocation in the big brown bat, Eptesicus fuscus

DEFF Research Database (Denmark)

Surlykke, Annemarie; Ghose, Kaushik; Moss, Cynthia F

2009-01-01

Echolocation allows bats to orient and localize prey in complete darkness. The sonar beam of the big brown bat, Eptesicus fuscus, is directional but broad enough to provide audible echo information from within a 60-90 deg. cone. This suggests that the big brown bat could interrogate a natural scene...

Bathymetry in the Classroom

Science.gov (United States)

Michael, Kurt Y.

2013-01-01

The "Titanic" caught the attention and imagination of the public when, in 1985, the sunken ship was discovered 370 miles off the coast of Newfoundland (PBS, 2012). Since that time, scientists have conducted numerous expeditions using high-resolution SONAR working in tandem with remote-operated vehicles (ROV) to collect information used…

Observations on the near-surface behaviour of sardinella schools in ...

African Journals Online (AJOL)

The schooling dynamics and swimming behaviour of sardinella Sardinella maderensis and S. aurita schooling near the surface in Angolan waters were recorded visually, using a calibrated echo integration system and a 95kHz high resolution sonar on board RV Dr Fridtjof Nansen during three cruises; July 1996, May 1997 ...

Ambient Noise Statistics for Sonar Modelling - Final Report

Science.gov (United States)

2005-05-01

traitement des données de bouées acoustiques EC-SWAN (bruit ambiant en eau peu profonde dans l’Est canadien) collectées mensuellement sur une période de 12...déplacé son champ d’intérêt de l’océan profond vers les eaux des zones littorales. L’acoustique en eau peu profonde présente un grand défi, car...l’expérience EC-SWAN (bruit ambiant en eau peu profonde dans l’Est canadien), ont été entreprises pour étudier les variations dans le temps et dans

High Frequency Sonar Elastic Image Enhancements: Ray Theory

National Research Council Canada - National Science Library

Marston, Philip

2001-01-01

.... All of the enhancements considered are associated with the target's mechanical response. An enhancement is discovered and analyzed for plastic and rubber cylinders usually considered to have weak backscattering...

Bathymetry and acoustic backscatter-outer mainland shelf, eastern Santa Barbara Channel, California

Science.gov (United States)

Dartnell, Peter; Finlayson, David P.; Ritchie, Andrew C.; Cochrane, Guy R.; Erdey, Mercedes D.

2012-01-01

In 2010 and 2011, scientists from the U.S. Geological Survey (USGS), Pacific Coastal and Marine Science Center (PCMSC), acquired bathymetry and acoustic-backscatter data from the outer shelf region of the eastern Santa Barbara Channel, California. These surveys were conducted in cooperation with the Bureau of Ocean Energy Management (BOEM). BOEM is interested in maps of hard-bottom substrates, particularly natural outcrops that support reef communities in areas near oil and gas extraction activity. The surveys were conducted using the USGS R/V Parke Snavely, outfitted with an interferometric sidescan sonar for swath mapping and real-time kinematic navigation equipment. This report provides the bathymetry and backscatter data acquired during these surveys in several formats, a summary of the mapping mission, maps of bathymetry and backscatter, and Federal Geographic Data Committee (FGDC) metadata.

FINAL TECHNICAL REPORT: Underwater Active Acoustic Monitoring Network For Marine And Hydrokinetic Energy Projects

Energy Technology Data Exchange (ETDEWEB)

Stein, Peter J. [Scientific Solutions, Inc, Nashua, NH (United States); Edson, Patrick L. [Scientific Solutions, Inc, Nashua, NH (United States)

2013-12-20

This project saw the completion of the design and development of a second generation, high frequency (90-120 kHz) Subsurface-Threat Detection Sonar Network (SDSN). The system was deployed, operated, and tested in Cobscook Bay, Maine near the site the Ocean Renewable Power Company TidGen™ power unit. This effort resulted in a very successful demonstration of the SDSN detection, tracking, localization, and classification capabilities in a high current, MHK environment as measured by results from the detection and tracking trials in Cobscook Bay. The new high frequency node, designed to operate outside the hearing range of a subset of marine mammals, was shown to detect and track objects of marine mammal-like target strength to ranges of approximately 500 meters. This performance range results in the SDSN system tracking objects for a significant duration - on the order of minutes - even in a tidal flow of 5-7 knots, potentially allowing time for MHK system or operator decision-making if marine mammals are present. Having demonstrated detection and tracking of synthetic targets with target strengths similar to some marine mammals, the primary hurdle to eventual automated monitoring is a dataset of actual marine mammal kinematic behavior and modifying the tracking algorithms and parameters which are currently tuned to human diver kinematics and classification.

Systems Approach to Defeating Maritime Improvised Explosive Devices in U.S. Ports

Science.gov (United States)

2008-12-01

with a few pounds of explosive in plastic pipes and a timer wrapped in trash bags to keep it afloat. One possible target was presidential hopeful...sonar, laser, gps, control system Benthos Modem Network REMUS reference Bouy WIFI Few equipment and parts N.A 5 3 2 1 5 4 Reliability prediction

77 FR 50289 - Taking and Importing Marine Mammals: Taking Marine Mammals Incidental to U.S. Navy Operations of...

Science.gov (United States)

2012-08-20

... areas of high marine animal densities, we believe that the incidental take of marine mammals would... response, tagging of free-ranging marine animals at-sea, and radar-based detection of marine mammals from... effects of sonar use will not be greater on animals listed under the ESA than the effects on other marine...

Autonomous Underwater Vehicle Architecture Synthesis for Shipwreck Interior Exploration

Science.gov (United States)

2015-12-01

GHz Quad-Core ARM cortex A9 processor ), brushless, 60 W DC motors, NESNE Electronics motor drivers, and a 540 Wh battery allowing for an operating... processor speed (Pentium M). The SLAM update rate is limited to the sonar array cycle time of 1 Hz. Fairfield et al. state that sensor degradation or

Controls on terrigenous sediment supply to the Arabian Sea during the late Quaternary: the Indus Fan.

NARCIS (Netherlands)

Prins, M.A.; Postma, G.; Cleveringa, J.; Cramp, A.; Kenyon, N.H.

2000-01-01

A previous study on the basis of long-range side-scan sonar data (Kenyon et al., 1995. Geometry of the younger sediment bodies of the Indus Fan. In: Pickering, K.T., Hiscott, R.N., Kenyon, N.H., Ricci Lucchi, F., Smith, R.D.A. (Eds.), Atlas of deep water environments: architectural style in

Acoustic and visual remote sensing of barrels of radioactive waste: Application of civilian and military technology to environmental management of the oceans

International Nuclear Information System (INIS)

Karl, H.A.; Chin, J.L.; Maher, N.M.; Chavez, P.S. Jr.; Ueber, E.; Van Peeters, W.; Curl, H.

1995-01-01

As part of an ongoing strategic research project to find barrels of radioactive waste off San Francisco, the U.S. Navy (USN), the U.S. Geological Survey (USGS), and the Gulf of the Farallones National Marine Sanctuary (GFNMS) pooled their expertise, resources, and technology to form a partnership to verify new computer enhancement techniques developed for detecting targets the size of 55 gallon barrels on sidescan sonar images. Between 1946 and 1970, approximately 47,800 large barrels and other containers of radioactive waste were dumped in the ocean west of San Francisco; the containers litter an area of the sea floor of at least 1400 km 2 knows as the Farallon Island Radioactive Waste Dump. The exact location of the containers and the potential hazard the containers pose to the environment is unknown. The USGS developed computer techniques and contracted with private industry to enhance sidescan data, collected in cooperation with the GFNMS, to detect objects as small as 55 gallon steel barrels while conducting regional scale sidescan sonar surveys. Using a subset of the regional sonar survey, images were plotted over a 125 km 2 area. The acoustic interpretations were verified visually using the USN DSV Sea Cliff and the unmanned Advanced Tethered Vehicle (ATV). Barrels and other physical features were found where image enhancement had indicated they would be found. The interagency cooperation among the USN, USGS, and GFNMS has led to develop a cost effective and time efficient method to locate the barrels of radioactive waste. This method has universal application for locating containers of hazardous waste over a regional scale in other ocean areas such as Boston Harbor and the Kara Sea in the Arctic. This successful application of military and civilian expertise and technology has provided scientific information to help formulate policy decisions that affect the environmental management and quality of the ocean

Processes of physical change to the seabed and bivalve recruitment over a 10-year period following experimental hydraulic clam dredging on Banquereau, Scotian Shelf

Science.gov (United States)

Gilkinson, K.; King, E. L.; Li, M. Z.; Roddick, D.; Kenchington, E.; Han, G.

2015-01-01

A previous study on the effects of experimental hydraulic clam dredging on seabed habitat and commercial bivalve populations revealed a lack of recovery after a 3-year post-dredging period (1998-2001) on a deep (65-75 m) offshore sandy bank on the Scotian Shelf, Canada. Follow-up sidescan sonar surveys were carried out 5 and 10 years after dredging (2003, 2008) in order to identify long-term processes of seabed recovery. Grab sampling was carried out 10 years after dredging to identify post-dredging commercial bivalve recruitment. Changes in the seafloor, including dredge tracks, were documented with a series of 7 sidescan sonar surveys between 1998 and 2008. A sediment mobility model was constructed based on modeled tidal current and hindcast wave data over this time period to quantify natural seabed disturbance and interpret changes to the dredge tracks mapped by sidescan sonar surveys. The model indicated that tidal currents had minimal effect on sediment mobilization. The main driving force associated with re-working of surficial sediments as evidenced by deterioration of dredge tracks in sonograms was annual fall/winter storms. While the annual frequency of storms and associated wave heights was variable, the observations and sediment mobility calculations suggest that the most influential variable is the magnitude of individual large storms, specifically storms with a significant wave height of ∼11 m. These storms are capable of generating mobile sediment layers of 20-30 cm thickness, equivalent to the dredge blade cutting depth. It appears that, with minor exceptions, sediment properties have returned to pre-dredging conditions 10 years after dredging in this habitat. Based on known age-length relationships, the four commercial bivalve species showed very low recruitment at the experimental site over the 10-year post-dredging period. However, this is unlikely due to a dredging effect since a similar pattern was observed in non-dredged areas.

A miniature research vessel: A small-scale ocean-exploration demonstration of geophysical methods

Science.gov (United States)

Howell, S. M.; Boston, B.; Sleeper, J. D.; Cameron, M. E.; Togia, H.; Anderson, A.; Sigurdardottir, T. D.; Tree, J. P.

2015-12-01

Graduate student members of the University of Hawaii Geophysical Society have designed a small-scale model research vessel (R/V) that uses sonar to create 3D maps of a model seafloor in real-time. A pilot project was presented to the public at the School of Ocean and Earth Science and Technology's (SOEST) Biennial Open House weekend in 2013 and, with financial support from the Society of Exploration Geophysicists and National Science Foundation, was developed into a full exhibit for the same event in 2015. Nearly 8,000 people attended the two-day event, including children and teachers from Hawaii's schools, home school students, community groups, families, and science enthusiasts. Our exhibit demonstrates real-time sonar mapping of a cardboard volcano using a toy size research vessel on a programmable 2-dimensional model ship track suspended above a model seafloor. Ship waypoints were wirelessly sent from a Windows Surface tablet to a large-touchscreen PC that controlled the exhibit. Sound wave travel times were recorded using an ultrasonic emitter/receiver attached to an Arduino microcontroller platform and streamed through a USB connection to the control PC running MatLab, where a 3D model was updated as the ship collected data. Our exhibit demonstrates the practical use of complicated concepts, like wave physics, survey design, and data processing in a way that the youngest elementary students are able to understand. It provides an accessible avenue to learn about sonar mapping, and could easily be adapted to talk about bat and marine mammal echolocation by replacing the model ship and volcano. The exhibit received an overwhelmingly positive response from attendees and incited discussions that covered a broad range of earth science topics.

Scanning behavior in echolocating common pipistrelle bats (Pipistrellus pipistrellus.

Directory of Open Access Journals (Sweden)

Anna-Maria Seibert

Full Text Available Echolocating bats construct an auditory world sequentially by analyzing successive pulse-echo pairs. Many other mammals rely upon a visual world, acquired by sequential foveal fixations connected by visual gaze saccades. We investigated the scanning behavior of bats and compared it to visual scanning. We assumed that each pulse-echo pair evaluation corresponds to a foveal fixation and that sonar beam movements between pulses can be seen as acoustic gaze saccades. We used a two-dimensional 16 microphone array to determine the sonar beam direction of succeeding pulses and to characterize the three dimensional scanning behavior in the common pipistrelle bat (Pipistrellus pipistrellus flying in the field. We also used variations of signal amplitude of single microphone recordings as indicator for scanning behavior in open space. We analyzed 33 flight sequences containing more than 700 echolocation calls to determine bat positions, source levels, and beam aiming. When searching for prey and orienting in space, bats moved their sonar beam in all directions, often alternately back and forth. They also produced sequences with irregular or no scanning movements. When approaching the array, the scanning movements were much smaller and the beam was moved over the array in small steps. Differences in the scanning pattern at various recording sites indicated that the scanning behavior depended on the echolocation task that was being performed. The scanning angles varied over a wide range and were often larger than the maximum angle measurable by our array. We found that echolocating bats use a "saccade and fixate" strategy similar to vision. Through the use of scanning movements, bats are capable of finding and exploring targets in a wide search cone centered along flight direction.

Overview of Fiber-Optical Sensors

Science.gov (United States)

Depaula, Ramon P.; Moore, Emery L.

1987-01-01

Design, development, and sensitivity of sensors using fiber optics reviewed. State-of-the-art and probable future developments of sensors using fiber optics described in report including references to work in field. Serves to update previously published surveys. Systems incorporating fiber-optic sensors used in medical diagnosis, navigation, robotics, sonar, power industry, and industrial controls.

Effects of Internal Waves on Sound Propagation in the Shallow Waters of the Continental Shelves

Science.gov (United States)

2016-09-01

resolves to f > 375 Hz . A frequency of 2 kHz, which is around the frequency range of a mid-frequency sonar, was used for the study and is well above...the 375 Hz threshold. 2. Gaussian Beam Option Ray trace models are unable to approximate the effects of caustics, which are regions of intense

Sea-floor morphology and sedimentary environments in western Block Island Sound, offshore of Fishers Island, New York

Science.gov (United States)

McMullen, Katherine Y.; Poppe, Lawrence J.; Danforth, William W.; Blackwood, Dann S.; Winner, William G.; Parker, Castle E.

2015-01-01

Multibeam-bathymetric and sidescan-sonar data, collected by the National Oceanic and Atmospheric Administration in a 114-square-kilometer area of Block Island Sound, southeast of Fishers Island, New York, are combined with sediment samples and bottom photography collected by the U.S. Geological Survey from 36 stations in this area in order to interpret sea-floor features and sedimentary environments. These interpretations and datasets provide base maps for studies on benthic ecology and resource management. The geologic features and sedimentary environments on the sea floor are products of the area’s glacial history and modern processes. These features include bedrock, drumlins, boulders, cobbles, large current-scoured bathymetric depressions, obstacle marks, and glaciolacustrine sediments found in high-energy sedimentary environments of erosion or nondeposition; and sand waves and megaripples in sedimentary environments characterized by coarse-grained bedload transport. Trawl marks are preserved in lower energy environments of sorting and reworking. This report releases the multibeam-bathymetric, sidescan-sonar, sediment, and photographic data and interpretations of the features and sedimentary environments in Block Island Sound, offshore Fishers Island.

A digital strategy for manometer dynamic enhancement. [for wind tunnel monitoring

Science.gov (United States)

Stoughton, J. W.

1978-01-01

Application of digital signal processing techniques to improve the non-linear dynamic characteristics of a sonar-type mercury manometer is described. The dynamic enhancement strategy quasi-linearizes the manometer characteristics and improves the effective bandwidth in the context of a wind-tunnel pressure regulation system. Model identification data and real-time hybrid simulation data demonstrate feasibility of approach.

Noise Tomography and Adaptive Illumination in Noise Radar

Science.gov (United States)

2015-10-01

transform of scatu , defined in (2.15), in y–direction can be written as 2 ( , , ) ( , ) 2 j dn n scat n y scat n y k EU k x d k e O k k j...and J. A. Henning , "Radar penetration imaging using ultra- wideband (UWB) random noise waveforms," IEE Proceedings-Radar Sonar and Navigation, vol

Assessing Beaked Whale Reproduction and Stress Response Relative to Sonar Activity at the Atlantic Undersea Test and Evaluation Center (AUTEC)

Science.gov (United States)

2015-09-30

especially pregnant females) this threshold is set somewhat arbitrary but judged and informed by the authors’ experience with over 2000 processed...Kellar N, Catelani K, Robbins M, Trego M, Allen C, Danil K, Chivers S (2015) Blubber cortisol: A potential tool for assessing stress response in free...6(3): e17009 doi:10.1371/journal.pone.0017009. PUBLICATIONS Kellar N, Catelani K, Robbins M, Trego M, Allen C, Danil K, Chivers S (2015

Classification methods of sonar signal. Part One: State of the art; Metodi di classificazione dei segnali Sonar. Parte prima: stato dell'arte

Energy Technology Data Exchange (ETDEWEB)

Colao, F [Dipartimento Tecnologie Fisiche e Nuovi Materiali, ENEA, Centro Ricerche Frascati, Roma (Italy); Dell' Erba, R [Dipartimento Tecnologie Fisiche e Nuovi Materiali, ENEA, Centro Ricerche Casaccia, Roma (Italy)

2009-07-01

STSS500 camera is an innovative instrument dedicated to submarine robot planned in order to increase human operator perception; the objectives include the possibility to operate in hostile atmospheres, the overcoming of the visible and/or infrared vision limits in turbid waters. STSS500 operates lighting by sound the scene with an array of acoustic rays with known electric characteristics. Later it listens to the reception antenna in order to record the reflected and/or diffuse acoustic echoes from the present obstacles in the scene. The camera is stereoscopic. An opportune analysis of signals receipted from the reception antenna renders the construction of synthetic data; the data fill in voxel a portion of the space place in front of the STS500. With simplifications of the physical phenomena the analysis of geometry of the lighted portion and the acoustic echoes is possible the localizations in the space and the physical dimensions of the voxel, and therefore to obtain the trend in the time of the reflected and/or diffused acoustic intensity from every given volume element. The main problem, that up to the present it is little studied, is dealing with the elaboration of the return echoes turns with the aim to extract those features related to the physical characteristics of the target, and whose visualization can help the process of understanding of the scene resumption from STS500. This the aspect is here inquired in detail, by means of the deepening and the study of the technical notes in literature that regard the identification and automatic classification and, the possible application to the case of acoustic data with typical characteristics dates from the camera that is to our disposition. Topic in this job is the use of well known techniques used in optical elaboration of satellite imaging, (methods PCA, SAM, SCM, etc). In this case we assuming that the specificities of the means and of the interaction has formally similar scale laws as in the event acoustic that in that optician; therefore we move to the acoustic within the paradigms and the algorithms originally developed for range and for interaction which as an example the frequency spectrum of optical data. [Italian] La telecamera STSS500 e uno strumento innovativo per la visione robotica sottomarina progettato per aumentare la percezione di un operatore umano i cui molteplici obiettivi includono sia la possibilita di operare in ambienti ostili, che il superamento dei limiti della visione con luce visibile e/o infrarossa in acque molto torbide. Lo strumento STSS500 opera insonificando la scena di riprendere con una serie di fasci acustici formati con caratteristiche elettroacustiche note, quindi si pone in ascolto la antenna di ricezione per registrare gli echi acustici riflessi e/o diffusi dagli ostacoli presenti nella scena. La telecamera e stereoscopica. Una opportuna analisi degli segnali ricevuti dall'antenna di ricezione rende possibile la costruzione di dati sintetici che tassellano in voxel una porzione dello spazio posto anteriormente all'STS500. Con opportune semplificazioni della realta fisica si affronta in questo studio l'analisi della geometria della porzione insonificata e degli echi acustici ricevuti da cui ricavare sia le localizzazioni nello spazio e le dimensioni fisiche dei voxel, e quindi ottenere l'andamento nel tempo dell'intensita acustica riflessa e/o diffusa da ciascun dato elemento di volume. Il problema principale, che e a tutt'oggi poco studiato, riguarda l'elaborazione degli echi di ritorno volta al fine di estrarre quelle features correlabili alle caratteristiche fisiche del bersaglio, e la cui visualizzazione possa aiutare il processo di comprensione della scena ripresa da STS500. Questo l'aspetto e indagato in dettaglio, mediante l'approfondimento e lo studio delle tecniche note in letteratura che riguardano la identificazione e classificazione automatica e la possibile applicazione al caso di dati acustici con caratteristiche tipiche date dalla telecamera che e a nostra disposizione. Centrale in questo lavoro e il tema del riuso di tecnologie robuste di analisi dati da settori di ricerca quali il telerilevamento o l'imaging ottico (metodi PCA, SAM, SCM, ecc). In questo caso, assumendo che le specificita del mezzo trasmissivo e dell'interazione abbiano leggi di scala formalmente simili sia nel caso acustico che in quello ottico, si trasferiscono all'ambito acustico i paradigmi e gli algoritmi originalmente sviluppati in ambiti diversi per range e per interazione quali ad esempio lo spettro di frequenza di dati ottici.

Pharmacy study of natural health product adverse reactions (SONAR): a cross-sectional study using active surveillance in community pharmacies to detect adverse events associated with natural health products and assess causality.

Science.gov (United States)

Necyk, Candace; Tsuyuki, Ross T; Boon, Heather; Foster, Brian C; Legatt, Don; Cembrowski, George; Murty, Mano; Barnes, Joanne; Charrois, Theresa L; Arnason, John T; Ware, Mark A; Rosychuk, Rhonda J; Vohra, Sunita

2014-03-28

To investigate the rates and causality of adverse event(s) (AE) associated with natural health product (NHP) use, prescription drug use and concurrent NHP-drug use through active surveillance in community pharmacies. Cross-sectional study of screened patients. 10 community pharmacies across Alberta and British Columbia, Canada from 14 January to 30 July 2011. The participating pharmacy staff screened consecutive patients, or agents of patients, who were dropping or picking up prescription medications. Patients were screened to determine the proportions of them using prescription drugs and/or NHPs, as well as their respective AE rates. All AEs reported by the screened patients who took a NHP, consented to, and were available for, a detailed telephone interview (14%) were adjudicated fully to assess for causality. Over a total of 105 pharmacy weeks and 1118 patients screened, 410 patients reported taking prescription drugs only (36.7%; 95% CI 33.9% to 39.5%), 37 reported taking NHPs only (3.3%; 95% CI 2.4% to 4.5%) and 657 reported taking prescription drugs and NHPs concurrently (58.8%; 95% CI 55.9% to 61.6%). In total, 54 patients reported an AE, representing 1.2% (95% CI 0.51% to 2.9%), 2.7% (95% CI 0.4% to 16.9%) and 7.3% (95% CI 5.6% to 9.6%) of each population, respectively. Compared with patients who reported using prescription drugs, the patients who reported using prescription drugs and NHPs concurrently were 6.4 times more likely to experience an AE (OR; 95% CI 2.52 to 16.17; ppharmacies take NHPs and prescription drugs concurrently, and of those, 7.4% (95% CI 6.3% to 8.8%) report an AE. A substantial proportion of community pharmacy patients use prescription drugs and NHPs concurrently; these patients are at a greater risk of experiencing an AE. Active surveillance provides a means of detecting such AEs and collecting high-quality data on which causality assessment can be based.

Resolution of Port/Starboard Ambiguity Using a Linear Array of Triplets and a Twin-Line Planar Array

Science.gov (United States)

2016-06-01

frequency modulation NATO North Atlantic Treaty Organization NF near-field NURC NATO Undersea Research Centre ONR Office of Naval Research PS port...1864) was a Brazilian Romantic poet, playwright, ethnographer, lawyer, and linguist. Excerpt reprinted in L. Lúcia Sá, Rain Forest Literatures...pushed by advances on ocean acoustics, electronics, and signal processing, towed sonars have improved drastically. Along with military

An Analysis of Wind Power Development in the Town of Hull, MA_Appendix 4_Geophysical Survey Report

Energy Technology Data Exchange (ETDEWEB)

Adams, Christopher

2013-06-30

CR Environmental, Inc. (CR) was contracted by GZA GeoEnvironmental, Inc. (GZA) to perform hydrographic and geophysical surveys of an approximately 3.35 square mile area off the eastern shore of Hull, Massachusetts. Survey components included: • Single-beam bathymetry; • 100-kHz and 500-kHz side scan sonar; • Magnetometry; and • Low to mid-frequency sub-bottom profiling.

Sequential Analysis: Hypothesis Testing and Changepoint Detection

Science.gov (United States)

2014-07-11

maintains the flexibility of deciding sooner than the fixed sample size procedure at the price of some lower power [13, 514]. The sequential probability... markets , detection of signals with unknown arrival time in seismology, navigation, radar and sonar signal processing, speech segmentation, and the... skimming cruise missile can yield a significant increase in the probability of raid annihilation. Furthermore, usually detection systems are

Balancing Work and Family: A Panel Analysis of the Impact of Part-Time Work on the Experience of Time Pressure

Science.gov (United States)

Laurijssen, Ilse; Glorieux, Ignace

2013-01-01

In this article we consider the consequences of work-family reconciliation, in terms of the extent to which the adjustment of the labour market career to family demands (by women) contributes to a better work-life balance. Using the Flemish SONAR-data, we analyse how changes in work and family conditions between the age of 26 and 29 are related to…