| An Acoustic-Instrumented Mine for Studying Subsequent Burial |
Jan-2007 |
15 pages |
| Authors:
Sean Griffin; John Bradley; Thiele; Maurice Jr; Michael D Richardson; Peter D Thorne; NAVAL RESEARCH LAB STENNIS SPACE CENTER MS MARINE GEOACOUSTICS DIV
|
 | The U.S. Navy is supporting the research to develop and validate stochastic, time-dependent, mine burial prediction models to aid the tactical decision making process. This research requires continuous monitoring of both mine behavior during burial, and the near-field processes responsible for burial. A new instrumented mine has been developed that far exceeds the capabilities of the earlier optically instrumented mine in terms of the burial processes that can be measured. ... |
|
| Mine Burial Experiments at the Martha's Vineyard Coastal Observatory |
Jan-2007 |
|
| Authors:
Peter Traykovski; Larry A Mayer; Michael D Richardson; James D Irish; WOODS HOLE OCEANOGRAPHIC INSTITUTION MA
|
 | Several experiments to measure post impact burial of seafloor mines by scour and fill have been conducted near the Woods Hole Oceanographic Institution's Martha's Vineyard Coastal Observatory (MVCO, Edgartown, MA). The sedimentary environment at MVCO consists of a series of rippled scour depressions (RSDs), which are large scale bedforms with alternating areas of coarse and fine sand. This allows simultaneous mine burial experiments in both coarse and fine sand under ... |
|
| Integration of Marine Mammal Movement and Behavior into the Effects of Sound on the Marine Environment |
Jan-2007 |
4 pages |
| Authors:
Dorian S Houser; BIOMIMETICA SANTEE CA
|
| Integration of the Marine Mammal Movement and Behavior (3MB) model into the Effects of Sound on the Marine Environment (ESME) program contributes to the ultimate goal of creating an environmental impact assessment tool for Navy acoustic activities in the ocean. The objectives of the effort are to 1) integrate the 3MB module into the second generation model of ESME, 2) incorporate the influence of bathymetric features on simulated marine mammal ... |
|
| Remote Identification of Seafloor Properties in Denied Areas |
Jan 2007 |
|
| Authors:
Larry Mayer; Luciano Fonseca; Barbara Kraft; Thomas Weber; Art Trembanis; NEW HAMPSHIRE UNIV DURHAM CENTER FOR COASTAL AND OCEAN MAPPING (CCOM)
|
| The long-term goal of this project is to develop techniques to collect and use remotely sensed acoustic data to make robust predictions of seafloor physical, acoustic and geotechnical properties in denied areas at spatial and temporal scales appropriate for tactical applications. The work described is a collaboration of research groups at the University of New Hampshire (CCOM) and the University of Delaware (CSHEL). The project aims to take advantage of ... |
|
| Object-Oriented Approach to Manipulating Acoustic and Seismic Spectra |
DEC 2006 |
42 pages |
| Authors:
D. K. Wilson; Jacob I. Torrey; COLD REGIONS RESEARCH AND ENGINEERING LAB HANOVER NH
|
| The software design and underlying mathematics for an object-oriented, Java-based approach to creating and manipulating frequency-dependent functions, such as power spectral densities, is described. The frequency dependence is modeled as a series of power-law bands, which provides a high degree of flexibility and efficiency for representing common spectral models such as evenly spaced bands, octave bands, narrow spectral lines, broadband noise, and power laws. Conversions between the various spectral models ... |
|
| Development of a Three Dimensional Perfectly Matched Layer for Transient Elasto-Dynamic Analyses |
DEC 2006 |
152 pages |
| Authors:
Anthony N. Johnson; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
|
| A time-dependent, three-dimensional finite element approach to the development of a perfectly matched layer for numerical calculations of surface wave radiation in a half space is presented. The development of this new element required the coupling of a system of linear, second-order, partial differential equations which describe elastic wave propagation into a single weak-form (Galerkin) wave equation, from which the characteristics of a composite finite element matching layer were derived. ... |
|
| Sensitivity of Bottom Topography on the Dynamics and Sound Speed Structure in the Northern Canary Current System |
DEC 2006 |
125 pages |
| Authors:
Alicia A. Hopkins; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
|
| The knowledge of the ocean environment, especially its littoral/coastal is important for current and future naval operations. In particular, an accurate description of the mesoscale variability of the surface and subsurface currents is essential for optimizing Navy missions. This study determines that different types of topographic smoothing and the addition of a volume constraint to a sigma-coordinate model significantly influences the generation, evolution, and maintenance of not only the surface ... |
|
| Design and Analysis of Side-Looking Sonar Experiments |
DEC 2006 |
129 pages |
| Authors:
Konstantinos Tsaprazis; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
|
| This research concerns the design and analysis of different Side-Looking Sonar experiments in order to satisfy different operational requirements. The different designs and analysis have been done via computer simulation. Side-Looking Sonar (also known as side-scan sonar) is known for very high quality, high resolution, ocean bottom imaging. Hence, it is used for bathymetric surveys commonly called seafloor mapping. It is able to rapidly survey large ocean areas for bottom ... |
|
| Algorithms for the Fusion of Two Sets of (Sonar) Data |
DEC 2006 |
|
| Authors:
P. A. de Theije; C. A. van Moll; TNO Defence Security and Safety The Hague (Netherlands)
|
| In this report we study different methods to combine sonar contacts as observed by two sonars. The sonar contacts are given realistic position errors, which makes their association non-trivial. First, for a single pair of contacts the most-likely position of the true underlying target position is derived. Based on this, the probability that two observed contacts originate from a single object is calculated. Based on these theoretical derivations, different association ... |
|
| The Automated Change Detection and Classification - Real-Time (ACDC-RT) System |
Dec-2006 |
16 pages |
| Authors:
Geary Layne; CHARLES MARTIN; Martin L Gendron; Christy Gautre; James Hammack; NAVAL RESEARCH LAB STENNIS SPACE CENTER MS
|
| In support of Military Mine Warfare (MIW) clearance operations for safe vessel passage, analysts perform change detection by visually comparing historical high-resolution sidescan sonar imagery (SSI) with newly collected SSI in an attempt to identify newly placed objects. The objective of MIW change detection is to match objects detected in new SSI with historical objects stored in a database. Any newly detected objects not successfully matched are flagged for investigation. ... |
|
| Progress Report on Advanced Detection and Classification Algorithms for Acoustic-Color-Based Sonar Systems |
29 NOV 2006 |
15 pages |
| Authors:
Lawrence Carin; Nilanjan Dasgupta; Steven Haron; SIGNAL INNOVATIONS GROUP INC DURHAM NC
|
| This report summarizes recent progress by Signal Innovations Group (SIG) in supporting the Naval Research Laboratory (NRL) on development of a new low-frequency sonar system. SIG has the tasks of developing the algorithms and transitioning them to NRL, for use in sea tests. The discussion below provides a summary of the following items: (i) a kernel-based matching pursuits classification algorithm, (ii) life-long learning, (iii) in situ learning, and (iv) a ... |
|
| KOJAK: Scalable Semantic Link Discovery Via Integrated Knowledge-Based and Statistical Reasoning |
NOV 2006 |
53 pages |
| Authors:
Hans Chalupsky; UNIVERSITY OF SOUTHERN CALIFORNIA MARINA DEL REY INFORMATION SCIENCES INST
|
| Link discovery (LD) is a new challenge in data mining whose primary concern is to identify strong links and discover hidden relationships among entities and organizations based on low-level, incomplete and noisy evidence data. Within this effort, USC/ISI addressed this challenge by developing a hybrid link discovery system called KOJAK that combines state-of-the-art knowledge representation and reasoning (KR&R) technology with statistical clustering analysis techniques from the area of data mining. ... |
|
| Acoustic Rapid COTS Insertion: A Case Study in Spiral Development |
30 OCT 2006 |
87 pages |
| Authors:
Michael Boudreau; NAVAL POSTGRADUATE SCHOOL MONTEREY CA GRADUATE SCHOOL OF BUSINESS AND PUBLIC POLICY
|
| Acoustic Rapid COTS Insertion (A-RCI) is a success story in the use of Modular Open Systems Approach (MOSA)/Open Architecture (OA) beginning with towed-array sonar on 688 Class Submarines and later encompassing all sonar systems on all attack submarines, some surface ship sonar applications, and even aviation anti-submarine warfare. The Department of Defense (DoD) has long considered Open Systems Design a best practice that should be used during system development. However, ... |
|
| Marine Seismic Surveys with Vector Acoustic Sensors |
01 OCT 2006 |
6 pages |
| Authors:
Dennis Lindwall; NAVAL RESEARCH LAB STENNIS SPACE CENTER MS SEAFLOOR SCIENCES DIRECTORATE
|
| Vector acoustic data will allow accurate three-dimensional imaging of a complex environment while corresponding pressure hydrophone data will fail. Newly developed sensors make vector acoustic-based surveys practical. This concept is demonstrated with data from an acoustic water tank. Using a simple but novel imaging algorithm, all of the main structures in the water tank were correctly located. This imaging algorithm uses none of the existing imaging or inversion methods common ... |
|
| Underwater Intruder Detection Sonar for Harbour Protection: State of the Art Review and Implications |
OCT 2006 |
|
| Authors:
Ronald T. Kessel; Reginald D. Hollett; NATO UNDERSEA RESEARCH CENTRE LA SPEZIA (ITALY)
|
| Sonar is the sensor of choice for wide-area underwater surveillance because sonar (based on sound waves) typically provides a much larger area of coverage than radar (electromagnetic waves) or video (visible light) can provide under water. Of particular interest of late is sonar for detecting and tracking underwater intruders in harbours, to provide an element of protection for ships, harbour infrastructure, nuclear power plants, and so forth, against terrorist attacks ... |
|
| Design of Synthetic Aperture Sonar Systems for High-Resolution Seabed Imaging (Tutorial Slides) |
OCT 2006 |
|
| Authors:
Marc Pinto; NATO UNDERSEA RESEARCH CENTRE LA SPEZIA (ITALY)
|
| This tutorial reviews the key aspects of the design of synthetic aperture sonar (SAS) systems for high resolution seabed imaging. After a quick overview of the expected benefits and main features of SAS, the design of the transmitter and receiver arrays is discussed, with emphasis on the mitigation of spatial aliasing with multi-element receiver arrays, wideband operation and extension to interferometric SAS for estimating the seabed bathymetry. The most difficult ... |
|
| Optimization of Army-Navy/Portable Special Search (AN/PSS)-14 Operator Training |
OCT 2006 |
88 pages |
| Authors:
Kristin M. Schweitzer; Bradley M. Davis; Bradley A. Pettijohn; Robert D. Clark; Alan D. Davison; James J. Staszewski; ARMY RESEARCH LAB ABERDEEN PROVING GROUND MD HUMAN RESEARCH AND ENGINEERING DIRECTORATE
|
| The research goal was to optimize Army-Navy/Portable Special Search (AN/PSS)-14 mine detector operator training duration and content. Results from training observations and analysis of Soldiers learning progression curves indicated that AN/PSS-14 operators who certified through the course were not adequately skilled. Results also showed that the operators learned little with regard to ground-penetrating radar (GPR) use and consequently were not confident in discriminating mines and clutter. The authors recommended a ... |
|
| Obstacle Detection and Avoidance Using Blazed Array Forward Look Sonar |
30 SEP 2006 |
10 pages |
| Authors:
A. J. Healey; D. P. Horner; S. P. Kragelund; NAVAL POSTGRADUATE SCHOOL MONTEREY CA CENTER FOR AUTONOMOUS UNDERWATER VEHICLE RESEARCH
|
| The long term goal of this project is to increase the level of autonomy in AUVs as they are being used for more complex missions than mine countermeasures. Part of this increase in autonomy will rely on obstacle detection and avoidance and will require a forward looking sonar (FLS) suitable for small vehicles. In the past year, the NPS Center for AUV Research has mounted a University of Washington Applied ... |
|
| Shallow Water UXO Technology Demonstration Site, Scoring Record Number 2 |
SEP 2006 |
49 pages |
| Authors:
Gary W. Rowe; William Burch; Christina McClung; ABERDEEN TEST CENTER MD
|
| This report documents the efforts of Tetra Tech EC, Inc., to detect and discriminate inert unexploded ordnance (UXO) using a Dual Acoustic and Magnetometer Array. Testing was conducted at ATC, Standardized Shallow Water UXO Technology Demonstration Site. A description of the tested system and an estimate of survey costs along with the analysis of the system performance are provided. |
|
| Time-Frequency, Bi-Frequency Detection Analysis of Noise Technology Radar |
SEP 2006 |
124 pages |
| Authors:
Eugene R. Heuschel; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
|
| Enemy integrated air defense systems (IADS) using low probability of intercept (LPI) emitters can cause significant problems for suppression of enemy air defense (SEAD) techniques. New threat emitter configurations using low-power random noise modulation have a significant processing gain unavailable to non-cooperative intercept receivers. Consequently, the detection of these emitters can not be accomplished with conventional intercept receiver detection methods. This thesis examines the use of time-frequency, bi-frequency signal detection ... |
|
| The Feasibility of Sodar Wind Profile Measurements from an Oceanographic Buoy |
SEP 2006 |
|
| Authors:
Allison M. Berg; MASSACHUSETTS INST OF TECH CAMBRIDGE
|
| This thesis explores the feasibility of making wind speed profile measurements from an oceanographic buoy using a Doppler sodar. In the fall of 2005, we deployed a Scintec SFAS sodar on an ASIS buoy. Roughly one week of buoy motion data and one day of sodar observations were collected. Data from both this deployment, and the Martha's Vineyard Coastal Observatory, were used in conjunction with models to predict sodar performance. ... |
|
| Classification of Underwater Objects Via Impulse Excitation |
Sep-2006 |
6 pages |
| Authors:
J T Cobb; Rodolfo Arrieta; Charles Bernstein; NAVAL SURFACE WARFARE CENTER PANAMA CITY FL
|
| A technique for classifying objects based on modeling the transient characteristics of their impulse response is developed and tested. A set of targets identical in geometry and differing in shell and filler material were constructed. The targets were manually struck exciting an impulse response which was sampled and recorded. The impulse response of each target was decomposed via windowed short-time Fourier transform into a set of feature vectors. The feature ... |
|
| Results from a Small Synthetic Aperture Sonar |
Sep-2006 |
7 pages |
| Authors:
Daniel Brown; Daniel Cook; Jose Fernandez; NAVAL SURFACE WARFARE CENTER PANAMA CITY FL
|
| A Synthetic Aperture Sonar (SAS) is capable of producing range-independent high-resolution imagery from an array that is small in length. The ability of these systems to operate at lower frequencies while maintaining high resolution has made them useful for mapping and searching large areas. The U.S. Navy through the Office of Naval Research has a history of developing SAS systems for mine hunting. Recently, their attention has turned to these ... |
|
| A Kernel Machine Framework for Feature Optimization in Multi-frequency Sonar Imagery |
Sep-2006 |
7 pages |
| Authors:
J R Stack; R Arrieta; X Liao; L Carin; NAVAL SURFACE WARFARE CENTER PANAMA CITY FL
|
| The purpose of this research is to optimize the extraction of classification features. This includes the optimal adjustment of parameters used to compute features as well as an objective and quantitative method to assist in choosing a priori data collection parameters (e.g., the insonification frequencies of a multi-frequency sonar). To accomplish this, a kernel machine is employed and implemented with the kernel matching pursuits (KMP) algorithm. The KMP algorithm is ... |
|
| Advances in Group Filter Applications to Sea Mine Detection |
Sep-2006 |
6 pages |
| Authors:
J T Cobb; M An; B Shenefelt; R Tolimieri; PROMETHEUS INC PANAMA CITY BEACH FL
|
| Automatic detection of sea mines in coastal regions is a difficult task due to the highly variable sea bottom conditions present in the underwater environment. Detection systems must be able to discriminate objects which vary in size, shape, and orientation from naturally occurring and man-made clutter. Additionally, these automated systems must be computationally efficient to be incorporated into unmanned underwater vehicle (UUV) sensor systems characterized by high sensor data rates ... |
|
| Time Varying Gain (TVG) Measurements of a Multibeam Echo Sounder for Applications to Quantitative Acoustics |
Sep-2006 |
|
| Authors:
Dezhang Chu; Hufnagle; Lawrence C Jr; WOODS HOLE OCEANOGRAPHIC INSTITUTION MA
|
| Protocols of calibration procedures of a multibeam echo sounder have been suggested previously [Foote et al., 2005, J. Acoust. Am. 117: 2013-2027], in which the time-varying-gain (TVG) of the multibeam system was assumed to follow the nominal system settings and was not investigated thoroughly. In the current study, the influence of the measured TVGs on system performance was investigated quantitatively. Specifically, measured TVGs were compared to those derived from the ... |
|
| Buried Object Classification using a Sediment Volume Imaging SAS and Electromagnetic Gradiometer |
Sep-2006 |
7 pages |
| Authors:
Daniel D Sternlicht; J K Harbaugh; Anjana K Shah; Michael L Webb; Richard Holtzapple; APPLIED SIGNAL TECHNOLOGY INC TORRANCE CA
|
| To advance naval capabilities in identifying buried mines and unexploded ordnance, hybrid systems that fuse data from disparate sensors are being developed. This paper describes preliminary results of a classification engine that combines target features and classification parameters from a synthetic aperture Buried Object Scanning Sonar (BOSS) and an electromagnetic Real-time Tracking Gradiometer (RTG). The target characteristics that generate signals of interest for these sensors (acoustic backscatter and induced changes ... |
|
| Adaptive Track Detection for Multi-Static Active Sonar Systems |
Sep-2006 |
7 pages |
| Authors:
Christian G Hempel; NAVAL UNDERSEA WARFARE CENTER DIV NEWPORT RI
|
| Multi-static active sonar systems detect contacts of interest by transmitting coherent waveforms and detecting the echoes on one or more receiving sensors. When a target of interest is in a region where its echoes are detectable by more than one receiver it can, in general, be declared sooner by combining the measurements from all sensors. The track detection schemes used in active sonar systems are often based on the Wald ... |
|
| 12.75 in. Synthetic Aperture Sonar (SAS), High Resolution and Automatic Target Recognition |
Sep-2006 |
8 pages |
| Authors:
Anthony D Matthews; Thomas C Montgomery; Daniel A Cook; John W Oeschger; John S Stroud; NAVAL SURFACE WARFARE CENTER PANAMA CITY FL
|
| The Autonomous Operations Future Naval Capability (AOFNC) program developed a 12.75 in. diameter autonomous underwater vehicle (AUV) and a Synthetic Aperture Sonar (SAS12) payload. This system falls under the lightweight designator of the Unmanned Undersea Vehicle (UUV) master plan. Bluefin Robotics Corporation and the Applied Research Laboratory of The Pennsylvania State University (ARL/PSU) developed the vehicle/payload system. In addition to the previous team members, Naval Surface Warfare Center Panama City ... |
|
| Autonomous Hydrophones at NOAA/OSU and a New Seafloor Sentry System for Real-time Detection of Acoustic Events |
Sep-2006 |
5 pages |
| Authors:
H Matsumoto; R P Dziak; D K Mellinger; M Fowler; J Haxel; Andy Lau; C Meinig; J Bumgardner; Walter Hannah; COOPERATIVE INST FOR MARINE RESOURCES SUTUDIES (CIMRS) NEWPORT OR
|
| Development is under way of a new intelligent autonomous hydrophone system, the Quasi-Eulerian hydrophone, or QUEphone. A tether-free portable hydrophone float with built-in data processor, it is capable of repeated vertical ascents and descents from seabed to surface using an internal buoyancy controller. While on the seafloor, it runs an acoustic event detection algorithm continuously; upon detection of a significant acoustic event, or at regular intervals, it surfaces to transmit ... |
|
| Broad-band Time Domain Modeling of Sonar Clutter in Range Dependent Waveguides |
Sep-2006 |
6 pages |
| Authors:
K D LePage; P Neumann; C W Holland; NAVAL RESEARCH LAB WASHINGTON DC
|
| A broadband time domain reverberation and clutter model has been developed to aid in the development of a better understanding of the environmental and system characteristics which drive sonar clutter in inhomogeneous waveguides. The theoretical background of the model is presented and its ability to model both diffuse background reverberation levels and clutter characteristics for a site on the Malta Plateau south of Sicily are evaluated. |
|
| Gabor Transform for Subband SAS Imaging |
Sep-2006 |
6 pages |
| Authors:
D Brown; J Wilbur; R J McDonald; NAVAL SURFACE WARFARE CENTER PANAMA CITY FL
|
| This paper describes a method for integrating a frequency-dependent object characterization into a practical sonar imaging system. Integration of joint time-frequency (JTF) processing into broadband SAS imaging enables one to add another dimension (frequency) to the object feature space without compromising resolution. JTF processing enables a user to construct a 3-D image description around objects of interest. The Gabor transform is used to capture the local frequency behavior in the ... |
|
| Benchmark Analysis of NURC Multistatic Tracking Capability |
AUG 2006 |
|
| Authors:
Odile Gerard; Stefano Coraluppi; Carthel Craig; Doug Grimmett; NATO UNDERSEA RESEARCH CENTRE LA SPEZIA (ITALY)
|
| This paper provides a brief description and performance results for the multistatic sonar trackers developed at NURC(NATO Undersea Research Center). Our analysis is based on common data distributed as part of the Multistatic Tracking Working Group (MSTWG), as well as sea trial data. We find that the nearest-neighbor tracker provides reasonable performance in benign environments, while the centralized and distributed MHT trackers have complementary strengths in more challenging scenarios. |
|
| Contact-Level Multistatic Sonar Data Simulator for Tracker Performance Assessment |
AUG 2006 |
|
| Authors:
Doug Grimmett; Stefano Coraluppi; NATO UNDERSEA RESEARCH CENTRE LA SPEZIA (ITALY)
|
| This paper provides an overview of a multistatic sonar contact-data simulation approach and a dataset generated specifically for tracker algorithm evaluation by the Multistatic Tracking Working Group (MSTWG). 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. We describe the methodology by which a single data set generated using this approach is ... |
|
| Benchmark Evaluation of Multistatic Trackers |
AUG 2006 |
|
| Authors:
Stefano Coraluppi; Doug Grimmett; Pascal de Theije; NATO UNDERSEA RESEARCH CENTRE LA SPEZIA (ITALY)
|
| This paper provides an overview of the Special Session on Multistatic Sonar and Radar Tracking at FUSION 2006. This includes background on the Multistatic Tracking Working Group, a brief description of the datasets and trackers that compose this working group at present, and a detailed discussion of a proposed set of tracker performance metrics. We identify a number of issues associated with performance assessment for target tracking. We conclude with ... |
|
| A Bayesian Approach to Predicting an Unknown Number of Targets Based on Sensor Performance |
AUG 2006 |
|
| Authors:
Karna Bryan; Craig Carthel; NATO UNDERSEA RESEARCH CENTRE LA SPEZIA (ITALY)
|
| Estimating remaining targets after some attempt has been made to detect an overall, unknown number of targets is critical to determining the potential threat associated with these remaining targets. This paper presents a Bayesian approach to calculate the distribution on the number of remaining targets given the sensor performance and the number of targets detected. For a single sensor, a closed form posterior distribution on remaining targets is derived. For ... |
|
| At-Sea Measurements of Diver Target Strengths at 100 kHz: Measurement Technique and First Results |
AUG 2006 |
|
| Authors:
R. D. Hollett; R. T. Kessel; M. Pinto; NATO UNDERSEA RESEARCH CENTRE LA SPEZIA (ITALY)
|
| During a recent at-sea trial of a diver detection system, the opportunity was taken of developing a technique for in-situ measurement of diver target strengths. The technique was based on making the diver perform circular maneuvers in front of the sonar to present all aspect angles to the sonar. The experimental set-up employed, the procedure employed, how the set-up complied with the far-field requisite and how the multipath effects were ... |
|
| Acoustic Environment of Haro Strait: Preliminary Propagation Modeling and Data Analysis |
AUG 2006 |
53 pages |
| Authors:
Christopher D. Jones; Michael A. Wolfson; WASHINGTON UNIV SEATTLE APPLIED PHYSICS LAB
|
| Field measurements and acoustic propagation modeling for the frequency range 1 10 kHz are combined to analyze the acoustic environment of Haro Strait of Puget Sound, home to the southern resident killer whales. Haro Strait is a highly variable acoustic environment with active commercial shipping, whale watching, and Naval activity. Southern resident killer whales are of unique public concern in this area because of increasing anthropogenic noise levels that may ... |
|
| Parametric Sub-Bottom Profiler for AUVs |
JUL 2006 |
5 pages |
| Authors:
Sean R. Griffin; Stephen C. Kuhn; Kim Benjamin; OMNI TECHNOLOGIES INC STENNIS SPACE CENTER MS
|
| Autonomous underwater vehicles (AUV) are fast becoming viable survey platforms. With this growth, new survey tools have emerged. The Naval Oceanographic Office's (NAVOCEANO) profiler for the Subsurface Autonomous Mapping System (SAMS) AUV (PFRS) was developed by Omni Technologies Inc. (OTI) to provide high-resolution, sub-bottom imagery (data). AUVs have stringent requirements in electrical power budget, size and weight requiring survey sensors that are smaller, lighter, autonomous and more energy efficient than ... |
|
| Spatial Correlation Coefficient Images for Ultrasonic Detection (Preprint) |
JUL 2006 |
24 pages |
| Authors:
Raina Cepel; K. C. Ho; Brett A. Rinker; Jr. Palmer; Terrence P. Lerch; Steven P. Neal; MISSOURI UNIV-COLUMBIA DEPARTMENT OF MECHANICAL AND AEROSPACE ENGINEERING
|
| In ultrasonics, image formation and detection are generally based on signal amplitude. In this paper, we describe an amplitude independent approach for image formation and detection based on the similarity of adjacent signals. Signal similarity is quantified in terms of the correlation coefficient calculated between A-scans digitized at adjacent measurement positions. Correlation coefficient images are introduced for visualizing the similarity in measured A-scans. In backscatter, the approach reveals defect signals ... |
|
| PAVAD B Design and Experimental Results Report |
30 JUN 2006 |
23 pages |
| Authors:
peter C. Herdic; Brian H. Houston; Robert D. Corsaro; NAVAL RESEARCH LAB WASHINGTON DC PHYSICAL ACOUSTICS BRANCH
|
| The application and experimental results are presented for the Passive and Advanced Vibro-Acoustic Treatments Demonstration, Part B (PAVAD-B) conducted at the Laboratory for Structural Acoustics, Naval Research Laboratory (NRL) during the winter and spring of 2001-2002. The goal of this demonstration is to utilize the most advanced treatments developed in the first part of the program (PAVAD-A), improve their design, and apply them to the Sponsor Supplied Structure. In the ... |
|
| Fulfilling the Roosevelts' Vision for American Naval Power (1923-2005) |
30 JUN 2006 |
73 pages |
| Authors:
Don DeYoung; Jill Dahlburg; Richard Bevilacqua; Gerald Borsuk; Jay Boris; Simon Chang; Richard Colton; Robert Eisenhauer; Herbert Eppert; Edward Franchi; NAVAL RESEARCH LAB WASHINGTON DC
|
| Since its establishment on July 2, 1923, the Naval Research Laboratory (NRL) has excelled in its mission of conducting a broadly based multidisciplinary program of scientific research and advanced technological development directed toward maritime applications of new and improved materials; techniques; equipment; systems; and ocean, atmospheric, and space sciences and related technologies. Products of the Laboratory include a number of innovations that have revolutionized the capabilities of the United States ... |
|
| Advanced Detection and Classification Algorithms for Acoustic-Color-Based Sonar Systems |
29 JUN 2006 |
7 pages |
| Authors:
Lawrence Carin; SIGNAL INNOVATIONS GROUP INC DURHAM NC
|
| Signal Innovations Group (SIG) has been working closely with the Naval Research Laboratory (NRL) on development of advanced algorithms for detection and classifying MCM targets, with data collected using the NRL sonar system. Over the current period of performance SIG has delivered to NRL kernel matching pursuits (KMP) software, that was employed by NRL at the most recent blind test. Details on the KMP algorithm are provided below. Additionally, NRL ... |
|
| An Optical Fiber Infrasound Sensor |
JUN 2006 |
19 pages |
| Authors:
Mark A. Zumberge; Jonathan Berger; CALIFORNIA UNIV REGENTS LA JOLLA CA SCRIPPS INST OF OCEANOGRAPHY
|
| We have designed a new type of infrasonic sensor using optical fibers as distributed sensing elements. The design addresses the limitations of the standard pipe filters currently used to average wind-generated, turbulent pressure fluctuations. In addition to maximizing the signal-to-noise ratio, the system has the capability to help estimate signal azimuth and phase velocity. The principal advantage of the Optical Fiber Infrasound Sensor (OFIS) over the standard pipe filter/microbaragraph combination ... |
|
| Characterization of the Infrasound Field in the Central Pacific |
JUN 2006 |
231 pages |
| Authors:
Milton Garces; Claus Hetzer; HAWAII UNIV KAILUA-KONA INFRASOUND LAB
|
| This document reviews the results of three years of infrasound recording and analysis at the Infrasound Laboratory (ISLA) of the University of Hawaii. ISLA is responsible for the operation and maintenance of infrasound station I59US, Kona, Hawaii. I59US entered into operations in July 2000 and was certified into the International Monitoring System (IMS) of the Comprehensive Nuclear-Test Ban Treaty (CTBT) in December 2001. The array site is in a tropical ... |
|
| Source Localization Using Wireless Sensor Networks |
JUN 2006 |
101 pages |
| Authors:
Stephen Tan Kok Sin; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
|
| Wireless sensors can be worn on soldiers or installed on vehicles to form distributed sensor networks to locate the source of sniper fire. A two-step source localization process is proposed for this sniper detection task. The time difference of arrival (TDOA) for the acoustic signals received by the sensors is first estimated using the generalized cross correlation (GCC) method. The estimated TDOA values are then used by the hybrid spherical ... |
|
| Non-Linear Acoustic Concealed Weapons Detector |
MAY 2006 |
60 pages |
| Authors:
Anjani Achanta; LUNA INNOVATIONS INC BLACKSBURG VA
|
| The major findings of this effort clearly demonstrate that Non-linear Acoustics is a low cost alternative to conventional imaging methods for concealed weapons detection. Our approach is to use ultrasonics to create a localized zone where non-linear interactions generate a lower frequency acoustic wave that is steerable and is able to penetrate clothing better than direct ultrasonics. We have been able to detect guns of various sizes, box cutters, knives ... |
|
| Time-Dependent Stochastic Inversion in Acoustic Travel-Time Tomography of the Atmosphere |
MAY 2006 |
11 pages |
| Authors:
Sergey N. Vecherin; Vladimir E. Ostashev; George H. Goedecke; D. K. Wilson; Alexander G. Voronovich; NEW MEXICO STATE UNIV LAS CRUCES DEPT OF PHYSICS
|
| Stochastic inversion is a well known technique for the solution of inverse problems in tomography. It employs the idea that the propagation medium may be represented as random with a known spatial covariance function. In this paper, a generalization of the stochastic inverse for acoustic travel-time tomography of the atmosphere is developed. The atmospheric inhomogeneities are considered to be random, not only in space but also in time. This allows ... |
|
| Environmentally Adaptive Reverberation Nulling |
15 APR 2006 |
11 pages |
| Authors:
William A. Kuperman; William S. Hodgkiss; SCRIPPS INSTITUTION OF OCEANOGRAPHY LA JOLLA CA MARINE PHYSICAL LAB
|
| This report describes the research performed on behalf of the Office of Naval Research (grant # N00014-01-D-0043 Delivery Order 0007) on the following: The feasibility of enhancing active target detection using environmentally adaptive reverberation nulling techniques has been demonstrated with experimental data and related simulations. |
|
| Regional Small-Event Identification Using Networks and Arrays of Seismic and Acoustic Sensors |
APR 2006 |
59 pages |
| Authors:
Michael A. Hedlin; SCRIPPS INSTITUTION OF OCEANOGRAPHY LA JOLLA CA
|
| Our work under this contract has had three primary objectives, but with the common theme of using seismic data to distinguish mining blasts from all other event types. We have used spectral characteristics of whole waveforms to discriminate industrial blasts from instantaneous explosions and earthquakes. We applied the automated time-frequency discriminant (AFTD) to several datasets to test transportability and robustness of the algorithm. The main conclusions of this work, described ... |
|
Acoustic Detection and Detectors
