| An Analysis of Undersea Glider Architectures and an Assessment of Undersea Glider Integration into Undersea Applications |
Sep 2012 |
91 pages |
| Authors:
William P Barker; NAVAL POSTGRADUATE SCHOOL MONTEREY CA DEPT OF SYSTEMS ENGINEERING
|
 | Currently, buoyancy driven underwater gliders are deployed globally to gather oceanographic data from across the world's oceans. This thesis examines the utility of underwater gliders within the context of providing additional U.S. Navy capabilities. An extensive survey of available underwater gliders was undertaken and the resultant survey pool of ten gliders was down selected to five gliders of fixed wing configuration. A comprehensive architectural analysis was then conducted of seven ... |
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| Clock Synchronization Through Time-Variant Underwater Acoustic Channels |
Sep 2012 |
104 pages |
| Authors:
Pascal Gagnon; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
|
| The goal of this work is to develop methodologies for synchronizing the clocks of neighboring nodes of an underwater acoustic network. Clock synchronization requires an estimate of the signaling time delay between the nodes, which is particularly challenging in the presence of multipath propagation through the acoustic communication channel. This thesis focuses on modeling the underwater acoustic communication channel, accounting for the multipath arrivals, and creating a set of signal ... |
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| Underwater Acoustic Network as a Deployable Positioning System |
Jun 2012 |
125 pages |
| Authors:
Rebecca E King; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
|
| Underwater acoustic communications networks serve to pass data between submerged nodes and a command and control center ashore. Range data recorded incident to regular transmissions between nodes afford the acoustic network an additional use as a navigational aide or tracking system for a vehicle operating in the network domain. Previous studies developed algorithms to solve for the position of the mobile node using node-to-node range data. An alternative localization algorithm ... |
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| Scoping Study on DRDC Toronto Future Research Regarding Naval Mine Countermeasures |
Jun 2012 |
50 pages |
| Authors:
Nada J Pavlovic; Geoffrey Ho; David Smith; Elaine Maceda; Simon Gowan; Neil Holden; Troy W Beechinor; Gary Bures; DEFENCE RESEARCH AND DEVELOPMENT TORONTO (CANADA)
|
| Canada currently possesses limited to modest Mine Counter Measure (MCM) capability that includes Maritime Coastal Defence Vessels (MCDVs) used for coastal surveillance and patrol, and Clearance Diving Units for identification and disposal of sea mines. In recognition of its MCM capability deficiencies, Canada has been actively involved in defining a program for integrating unmanned underwater vehicles (UUVs) in current MCM operations through collaboration with other Allied nations. In line with ... |
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| HBOI Underwater Imaging and Communication Research - Phase 1 |
19 Apr 2012 |
14 pages |
| Authors:
Fraser R Dalgleish; FLORIDA ATLANTIC UNIV FORT PIERCE FL HARBOR BRANCH OCEANOGRAPHIC INST
|
| The long term goal of this program is to advance understanding of distributed laser line scan (DLLS) imaging and networking techniques and their applicability to Navy missions which utilize multiple UUVs in support of littoral operations. The planned three year outcome of the work is to provide a validated radiative transfer simulation suite which can allow underwater laser imaging and communications system developers or operators to predict imaging or communication ... |
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| Infrastructure for Large-Scale Tests in Marine Autonomy |
Feb 2012 |
148 pages |
| Authors:
Robert A Hummel; MASSACHUSETTS INST OF TECH CAMBRIDGE DEPT OF MECHANICAL ENGINEERING
|
| This thesis focuses on the development of infrastructure for research with large-scale autonomous marine vehicle fleets and the design of sampling trajectories for compressive sensing (CS). The newly developed infrastructure includes a bare-bones acoustic modem and two types of low cost and scalable vehicles. One vehicle is a holonomic raft designed for station keeping and precise maneuvering, and the other is streamlined kayak for travelling longer distances. The acoustic modem, ... |
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| Unmanned Systems Integrated Roadmap FY2011-2036 |
Oct 2011 |
109 pages |
| Authors:
OFFICE OF THE UNDER SECRETARY OF DEFENSE (ACQUISITION TECHNOLOGY AND LOGISTICS) WASHINGTON DC
|
| U.S. and allied combat operations continue to highlight the value of unmanned systems in the modern combat environment. Combatant Commanders (CCDRs) and warfighters value the inherent features of unmanned systems, especially their persistence, versatility, and reduced risk to human life. The U.S. military Services are fielding these systems in rapidly increasing numbers across all domains: air, ground, and maritime. Unmanned systems provide diverse capabilities to the joint commander to conduct ... |
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| Robust High Data Rate MIMO Underwater Acoustic Communications |
30 Sep 2011 |
24 pages |
| Authors:
Jian Li; FLORIDA UNIV GAINESVILLE DEPT OF ELECTRICAL AND COMPUTER ENGINEERING
|
| Our research focuses on mobile multi-input multi-output communications over sparse acoustic channels subject to both inter-symbol interference and Doppler scaling effects. Temporal resampling is implemented to effectively convert the Doppler scaling effects to Doppler frequency shifts. We evaluate two practical channel models and compare the performance of the corresponding channel estimation algorithms, namely, the generalization of the sparse learning via iterative minimization (GoSLIM) algorithm and its variation, GoSLIM-V. For symbol ... |
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| Modeling the Acoustic Channel for Simulation Studies |
30 Sep 2011 |
11 pages |
| Authors:
Michele Zorzi; PADOVA UNIV (ITALY) DIPARTIMENTO DI INGEGNERIA DELL' INFORMAZIONE
|
| The project started on 04/01/10, and the reporting period covers from 09/01/10 to 08/31/11. The main objective for this period was to gain deep insight on the propagation phenomena that most affect underwater acoustic systems, based on the experimental data made available to us. Key behaviors have been sought and quantified, including sparsity, stationarity, and predictability. Insights on how these channel properties can be used for system design have been ... |
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| Analysis of and Techniques for Adaptive Equalization for Underwater Acoustic Communication |
Sep 2011 |
218 pages |
| Authors:
Ballard J Blair; MASSACHUSETTS INST OF TECH CAMBRIDGE
|
| Underwater wireless communication is quickly becoming a necessity for applications in ocean science, defense, and homeland security. Acoustics remains the only practical means of accomplishing long-range communication in the ocean. The acoustic communication channel is fraught with difficulties including limited available bandwidth, long delay-spread, time-variability, and Doppler spreading. These di difficulties reduce the reliability of the communication system and make high data-rate communication challenging. Adaptive decision feedback equalization is a ... |
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| Fluctuations of Broadband Acoustic Signals in Shallow Water |
Sep 2011 |
10 pages |
| Authors:
Mohsen Badiey; DELAWARE UNIV NEWARK COLL OF EARTH OCEAN AND ENVIRONMENT
|
| The scientific objective of this research is to understand acoustic wave propagation in a dynamic environment in two frequency bands: Low (50 Hz to 500 Hz) and Mid-to-High (500 Hz to 25 kHz). The goal for the low frequency band is to assess the effects of internal waves on acoustic wave propagation, with an emphasis on the mechanisms that cause significant acoustic temporal and spatial intensity fluctuations. The goal for ... |
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| Shallow Water Propagation and Surface Reverberation Modeling |
Sep 2011 |
8 pages |
| Authors:
Grant B Deane; SCRIPPS INSTITUTION OF OCEANOGRAPHY LA JOLLA CA
|
| The primary long-term goal is to measure and model high-frequency acoustic propagation in the presence of surface gravity waves and breaking waves to better understand the effects of surface reverberation on shallow water, underwater acoustic communications (ACOMS). Secondary long-term goals are to exploit measurements of breaking wave noise to infer bubble cloud populations at the sea surface and their effect on reverberation, and to model high-frequency, forward scattering from sea ... |
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| Ocean Variability Effects on Underwater Acoustic Communications |
Sep 2011 |
8 pages |
| Authors:
Aijun Song; Mohsen Badiey; DELAWARE UNIV NEWARK COLL OF MARINE AND EARTH STUDIES
|
| This proposed research seeks to identify, explain, and ultimately predict, the factors that significantly alter the operational effectiveness of underwater acoustic communications through experimental work and theoretical analysis. The long-term goal is to develop reliable, high rate transceivers customized for coherent underwater acoustic communications. The research objective is to investigate the relationship between environmental fluctuations and the performance of coherent underwater acoustic communications at high frequencies (8-50 kHz) through experimental ... |
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| Adaptive Reception for Underwater Communications |
JUN 2011 |
186 pages |
| Authors:
Spyridon Dessalermos; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
|
| This research concerns the development of an adaptive receiver for underwater communication. In this type of wireless link, the radio channel is replaced by an underwater acoustic channel, which is strongly dependent on the physical properties of the ocean medium and its boundaries, the link geometry and the ambient noise. Traditional acoustic communications have involved a priori matching of the signaling parameters to the expected characteristics of the channel. To ... |
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| HBOI Underwater Imaging and Communications Research - Phase I |
2010 |
12 pages |
| Authors:
Fraser R. Dalgleish; HARBOR BRANCH OCEANOGRAPHIC INST INC FORT PIERCE FL
|
| The long term goal of this program is to advance understanding of distributed laser line scan (DLLS) imaging and networking techniques and their applicability to Navy missions which utilize multiple UUVs in support of littoral operations. The planned three year outcome of the work is to provide a validated radiative transfer simulation suite which can allow underwater laser imaging and communications system developers or operators to predict imaging or communication ... |
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| Cooperative Autonomous Underwater Vehicles Used to Search Large Ocean Areas for Mines |
27-Oct-2009 |
6 pages |
| Authors:
Dean B Edwards; IDAHO UNIV MOSCOW CENTER FOR INTELLIGENT SYSTEMS RESEARCH
|
| The overall objective of the research was to develop and apply strategies for autonomous collaboration among UUVs to search for underwater mines. We successfully simulated six behavior modules including Navigation and Formation Control, Vehicle Replacement, Divert to MLO for Inspection, Leader Replacement, Deployment and Recovery, and Multi-Vehicle Sensing. All these modules were implemented and simulated on the MOOS platform except for Multi-Vehicle Sensing. We also defined and developed a mapping ... |
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| Monitoring Cetaceans in the North Pacific |
Apr-2009 |
18 pages |
| Authors:
Kathleen M Stafford; WASHINGTON UNIV SEATTLE APPLIED PHYSICS LAB
|
| Two projects were undertaken to monitor cetaceans in the North Pacific. The first was designed to obtain passive acoustic data from the U.S. Navy's Northern Edge Range. Three instruments were deployed in April 2008 to monitor both high (up to 25 kHz) and low (up to 1 kHz) frequencies for odontocetes and mysticetes, respectively. Unfortunately, these instruments did not record any data. The second project was to analyze retrospective data ... |
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| Modeling and Frequency Tracking of Marine Mammal Whistle Calls |
FEB 2009 |
108 pages |
| Authors:
Jared Severson; MASSACHUSETTS INST OF TECH CAMBRIDGE
|
| Marine mammal whistle calls present an attractive medium for covert underwater communications. High quality models of the whistle calls are needed in order to synthesize natural-sounding whistles with embedded information. Since the whistle calls are composed of frequency modulated harmonic tones, they are best modeled as a weighted superposition of harmonically related sinusoids. Previous research with bottlenose dolphin whistle calls has produced synthetic whistles that sound too "clean" for use ... |
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| Developing Fleets of Autonomous Underwater Vehicles |
31-Mar-2008 |
11 pages |
| Authors:
Dean B Edwards; IDAHO UNIV MOSCOW CENTER FOR INTELLIGENT SYSTEMS RESEARCH
|
| Autonomous underwater vehicles (AUVs) have a demonstrated capability to collect valuable data for scientific and military purposes. Historically, individual vehicles have been used. To reduce the overall time and cost of acquiring data over large areas, multiple vehicles must be used. A fleet of 5 AUVs, capable of underwater commendation, were fabricated. Languages and logics were developed to enable collaborative operations among the vehicles. Experiments with a formation of 5 ... |
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| Multi-Static Detection and Localization of Buried Targets using Synthetic Aperture Iterative Time-Reversal Processing |
30 SEP 2007 |
7 pages |
| Authors:
W. A. Kuperman; Karim Sabra; SCRIPPS INSTITUTION OF OCEANOGRAPHY LA JOLLA CA MARINE PHYSICAL LAB
|
| To use an iterative time-reveral techniques to provide robust focusing along the ocean bottom, with little signal processing effort involved and a-priori information on the environment, to enhance the detection and localization of proud or buried target in shallow water. The second goal of providing undersea communications augment this program is being addressed outside the SWAMSI efort but would come together in the final demo. |
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| Waves, Bubbles, Noise, and Underwater Communications |
30 SEP 2007 |
7 pages |
| Authors:
Grant B. Deane; SCRIPPS INSTITUTION OF OCEANOGRAPHY LA JOLLA CA MARINE PHYSICAL LAB
|
| The long term goals are to (1) understand the role of wave-induced bubbles in the upper ocean boundary layer on the performance of underwater communications systems and ambient noise generation, (2) study the implications of focusing by surface gravity waves on Doppler sonar and acoustic communications systems in shallow and very shallow water, and (3) study the performance of acoustic vector sensors in very shallow water. |
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| High Frequency Acoustical Propagation and Scattering in Coastal Waters |
30 SEP 2007 |
7 pages |
| Authors:
David M. Farmer; RHODE ISLAND UNIV NARRAGANSETT GRADUATE SCHOOL OF OCEANOGRAPHY
|
| To study the physical processes controlling the propagation of high frequency acoustical signals. Of particular interest is the relationship between bubble distributions, surface gravity waves and turbulence and their effects on sound propagation as it affects underwater communication. A second long-term goal is to model these processes to improve our understanding and to enhance the predictive capabilities. |
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| Shallow Water Fluctuations and Communications |
30 SEP 2007 |
7 pages |
| Authors:
H. C. Song; W. A. Kuperman; SCRIPPS INSTITUTION OF OCEANOGRAPHY LA JOLLA CA MARINE PHYSICAL LAB
|
| The central effort of this research will be the development of robust algorithms for reliable, high data rate, acoustic communications in a dynamic ocean environment and demonstration of their use with data collected in a shallow water environment. |
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| Numerical Modeling of Acoustic Propagation in a Variable Shallow Water Waveguide |
30 Sep 2007 |
6 pages |
| Authors:
Daniel Rouseff; WASHINGTON UNIV SEATTLE APPLIED PHYSICS LAB
|
| Random variability in shallow water will induce variability in a propagating acoustic field. The long-term goal of this research is to quantify how random variability in the ocean environment translates into random variability in the acoustic field and the associated signal processing algorithms. In the present funding cycle, the emphasis is on underwater acoustic communication. |
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| Bubbles and Acoustic Communications Experiment (SPACE07): Acoustical and Physical Characteristics of Diffuse Bubble Plumes |
30 Sep 2007 |
5 pages |
| Authors:
Svein Vagle; INSTITUTE OF OCEAN SCIENCES SIDNEY (CANADA)
|
| The scientific rationale for SPACE07 is that even though reliable underwater acoustic communication is central to the Navy's vision and Concept of Operations (CONOPS) for the future, and while significant progress in communications system development has been made in the last 15 years, current techniques fall far short of what is needed in terms of the data rates, the range of environments and operating conditions, and levels of covertness at ... |
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| A Research Program on the Asymptotic Description of Electromagnetic Pulse Propagation in Spatially Inhomogeneous Temporally Dispersive, Attenuative Media |
SEP 2007 |
41 pages |
| Authors:
Kurt E. Oughstun; VERMONT UNIV BURLINGTON COLL OF ENGINEERING AND MATHEMATICS
|
| The results of this analysis have direct, meaningful application to the analysis and design of low-observable surfaces (for stealth airframes) and ultra-wideband radar systems (for observing stealth airframes), the remote detection of buried structures (such as land-mines and IED's), ionospheric pulse propagation (for remote sensing from an orbiting satellite), as well as the problem of ultra-wideband electromagnetic pulse exposure of biological tissues. Of further interest is the application of this ... |
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| Characterization and Modeling of Underwater Acoustic Communications Channels for Frequency-Shift-Keying Signals |
Sep-2006 |
7 pages |
| Authors:
Wen-Bin Yang; T C Yang; NAVAL RESEARCH LAB WASHINGTON DC
|
| In a fading channel, bit error rate for frequency-shift- keying signals is determined predominantly by the envelope amplitude fading statistics of the signal. The narrowband envelope amplitude distributions are measured from the TREX04 data (as a function of frequency) using M-sequence signals centered at 17 kHz with a 5 kHz bandwidth. The results do not fit the Rayleigh, Rician, Nakagami m-distributions. In contrast, we find that the data are fitted ... |
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| Support Platform and Communications to Manage Cooperative AUV Operations |
2006 |
9 pages |
| Authors:
T. R. Cuff; R. W. Wall; IDAHO UNIV MOSCOW
|
| For the testing of control and communications algorithms in cooperative behavior, a fleet of autonomous underwater vehicles (AUVs) is under development by the University of Idaho. This paper discusses one piece of the puzzle in this fleet: the communications module to manage multiple agents. The communications system provides multiple modes of operation. Different communications mediums to and from the vehicle support these modes of operation. The tools supplied by the ... |
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| Secretary of the Navy/Chief of Naval Operations Chairs of Oceanographic Sciences |
2006 |
4 pages |
| Authors:
W. A. Kuperman; SCRIPPS INSTITUTION OF OCEANOGRAPHY LA JOLLA CA MARINE PHYSICAL LAB
|
| The long term goals are: The central efforts are to conduct research in ocean acoustics and signal processing, educate graduate students and participate in the ONR research community. The objectives are to conduct long term basic research in ocean acoustics with emphasis on involving graduate students, post docs and junior researchers in the research. Concerning graduate students, goals include both exploring research ideas that may lead to thesis research and ... |
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| Allocating AUVs for Mine Map Development in MCM |
2006 |
9 pages |
| Authors:
Andrew Rajala; Dean Edwards; IDAHO UNIV MOSCOW CENTER FOR INTELLIGENT SYSTEMS RESEARCH
|
| When cooperating Autonomous Underwater Vehicles (AUVs) are used for large area mine countermeasures (MCM), it is important for each vehicle to have a map of the entire search area. If each AUV only has a map of the area it has covered, that information will be lost if the vehicle is lost. To build a complete coverage map in each AUV, a scheduling algorithm, language, and logic were developed. The ... |
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| Quantitative Side-Scan Research for Sediment Characterization |
30 Sep 2005 |
4 pages |
| Authors:
Jerald W Caruthers; UNIVERSITY OF SOUTHERN MISSISSIPPI STENNIS SPACE CENTER DEPT OF MARINE SCIENCE
|
| The long-term goals of this work are to contribute to the understanding of bottom backscatter at high frequencies, provide techniques for determining sediment characteristics based on backscatter, and to support experiments within the context of the high-frequency, underwater communications and bottom scattering experiments such as KauaiEx and SAX04. |
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| Underwater Acoustic Communications |
30 Sep 2005 |
8 pages |
| Authors:
Andrey K Morozov; Douglas C Webb; James C Preisig; Lee E Freitag; WEBB RESEARCH CORP EAST FALMOUTH MA
|
| The goal of this project is to investigate innovative methods in underwater acoustic mobile communications on the basis of OFDM, which can be applied for short-range high-rate communication and for long-range low data rate channel. |
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| Undersea Navigation via a Distributed Acoustic Communications Network |
JUN 2005 |
70 pages |
| Authors:
Matthew J. Hahn; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
|
| Acoustic modems are the basis for emerging undersea wireless communications networks. US Navy Seaweb technology offers an opportunity to perform undersea navigation and tracking by virtue of node-to-node ranging measurements acquired as a by-product of the acoustic communications protocol. A simple localization algorithm is developed and verified with synthetic data and is then tested with an Unmanned Undersea Vehicle (UUV) during an experiment at sea. |
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| Dynamic Virtual LANs for Adaptive Network Security |
01 NOV 2004 |
|
| Authors:
Diego Merani; Alessandro Berni; Michel Leonard; NATO UNDERSEA RESEARCH CENTRE LA SPEZIA (ITALY)SUPREME ALLIED
|
 | The development of Network-Enabled capabilities in support of undersea research requires architectures for the interconnection and data sharing that are flexible, scalable, and built on open standards. This is essential to ensure transparent interoperability between shore laboratories (both NATO and national) and assets located at sea (research vessels, buoys, autonomous vehicles, sensors and acquisition systems). Also, a wide range of communications media needs to be supported (e.g. SATCOM, wireless at-hoc ... |
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| Surface Wave Focusing and Acoustic Communications in the Surf Zone |
OCT 2004 |
|
| Authors:
James C. Preisig; Grant B. Deane; WOODS HOLE OCEANOGRAPHIC INSTITUTION MA DEPT OF APPLIED OCEAN PHYSICS AND ENGINEERING
|
| The forward scattering of acoustic signals off of shoaling surface gravity waves in the surf zone results in a time-varying channel impulse response that is characterized by intense, rapidly fluctuating arrivals. In some cases, the acoustic focusing by the curvature of the wave crest results in the formation of caustics at or near a receiver location. This focusing and the resulting caustics present challenges to the reliable operation of phase ... |
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| Predicting the Effects of Sea Surface Scatter on Broadband Pulse Propagation With an Ocean Acoustic Parabolic Equation Model |
JUN 2004 |
93 pages |
| Authors:
Richard M. Ead; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
|
| Littoral waters when compared to the open ocean create an environment of greater reverberation with acoustic energy scattering from the sea surface, bottom, topographic features, and regions that lack homogeneity within the volume. If the ocean surface is rough on the scale of an acoustic wavelength, considerable scattering can occur that can significantly influence coherent propagation. Because the rough surface is also evolving dynamically such scattering can introduce Doppler shifting ... |
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| "Follow the Leader" Tracking by Autonomous Underwater Vehicles (AUVs) Using Acoustic Communications and Ranging |
SEP 2003 |
208 pages |
| Authors:
Daniel P. Kucik; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
|
| With advances in computer and sensor technologies, autonomous underwater vehicles (AUVs) are now capable of reaching a level of independent action once thought impossible. Through the use of cooperative behaviors it is possible to further increase their autonomy by allowing multiple operating AUVs to simultaneously coordinate their activities to improve the efficiency and effectiveness of the overall system. This thesis research defines the algorithms and rules needed to perform 'follow ... |
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| Adaptive Oceanographic Sampling in a Coastal Environment Using Autonomous Gliding Vehicles |
AUG 2003 |
|
| Authors:
David M. Fratantoni; WOODS HOLE OCEANOGRAPHIC INSTITUTION MA DEPT OF PHYSICAL OCEANOGRAPHY
|
| The long-term goal of this program is to develop an efficient, mobile, infrastructure-free, ocean-observing system composed of high-endurance, low-cost autonomous vehicles with near-global range and modular sensor payload. Particular emphasis is placed on the development of adaptive sampling strategies and the intelligent control of large glider fleets operating within the framework of an autonomous oceanographic sampling network. The primary objective of the program is to develop and demonstrate moderate-term (weeks) ... |
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| Efficient Protocols for Integrated Communication and Formation Control in UUV Task Forces |
21 JUL 2003 |
7 pages |
| Authors:
Rajgopal Kannan; Brian S. Bourgeois; NAVAL RESEARCH LAB STENNIS SPACE CENTER MS MARINE GEOSCIENCES DIV
|
| We propose a new message-efficient communication protocol for maintaining ranging and positional formation in a dynamically moving UUV task force. The protocol offers several attractive features including implementation simplicity, low message overhead and robustness. The proposed protocol is not stand-alone, the formational aspects of the protocol are integrated with other aspects of inter-vessel communication, including data transfer and control. Medium access control, data communication and ranging are implemented via an ... |
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| Link-Layer and Network-Layer Performance of an Undersea Acoustic Network at Fleet Battle Experiment-India |
JUN 2003 |
53 pages |
| Authors:
Grant I. Hartfield; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
|
| This thesis is an analysis of the link-layer and network-layer performance of an experimental Seaweb undersea acoustic network. The objective is to statistically determine RTS/CTS handshaking and ARQ retransmission performance during the Fleet Battle Experiment-India, executed in June 2001. Many factors constrain or impair undersea acoustic communications. Analysis of a sample portion of the data reveals insights about the overall throughput, latency, and reliability of the Seaweb network. Seaweb is ... |
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| Detection of Binary Phase-Shift Keying Signal in Multipath Propagation |
JUN 2002 |
|
| Authors:
Du S. Jung; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
|
| Time-varying dispersion and multipath propagation in a shallow underwater environment causes intersymbol interference in underwater communication. This thesis investigates a mitigation procedure for communication using a Binary Phase-Shift Keying (BPSK) signal. The method employed uses the time-reversed ocean impulse response to mitigate the degradation of the bit error rate performance. All results were achieved by the use of computer simulation of typical shallow water environments. |
|
| UUV Teams For Deep Water Operations |
11 DEC 2001 |
8 pages |
| Authors:
Brian S. Bourgeois; Patrick M. McDowell; NAVAL RESEARCH LAB STENNIS SPACE CENTER MS MARINE GEOSCIENCES DIV
|
| This paper presents the Unmanned Underwater Vessel (UUV) team concept, and discusses the goals of a new research effort at the Naval Research Laboratory (NRL) to develop the technologies required to implement this concept. The UUV team concept is essential to rapid and covert near-shore military operations where a communication and navigation infrastructure is not available. The UUV team concept also has the potential for lowering the cost of deepwater ... |
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| Underwater Acoustic Data Communications for Autonomous Platform Command, Control and Communications |
12 FEB 2001 |
140 pages |
| Authors:
Michael Shinego; Geoff Edelson; Francine Menas; Michael Richman; Robert Nation; BAE SYSTEMS AND TECHNOLOGY NASHUA NH
|
| The purpose of this study is to provide an analysis and assessment of the state-of-the-art of underwater acoustic (UWA) data communications technology with application to multiple vehicle operation in support of shallow-water mine countermeasures (MCM) operations. This study is intended to provide system architects with a reference to what the current state of acoustic communications technology can provide and to support the execution of system architecture trades. Included are discussions ... |
|
| UUV Master Plan: A Vision for Navy UUV Development |
SEP 2000 |
8 pages |
| Authors:
B. Fletcher; SPACE AND NAVAL WARFARE SYSTEMS CENTER SAN DIEGO CA
|
| At the request of the Assistance Secretary of the Navy for Research, Development and Acquisition (ASN-RDA). The Navy Unmanned Undersea Vehicle (UUV) Master Plan was prepared, outlining recommended development pathways for UUV systems and technologies for the next decade and beyond. An overall vision of UUVs as integral parts of the battle force is portrayed, with four signature capabilities seen as critical to both near term and long term goals. ... |
|
| Communication, Feedback and Decentralized Control for Platoons of Underwater Vehicles |
11 AUG 2000 |
38 pages |
| Authors:
Daniel J. Stilwell; Bradley D. Bishop; NAVAL ACADEMY ANNAPOLIS MD DIV OF ENGINEERING AND WEAPONS
|
| Since communications bandwidth underwater is severely limited, platoons of underwater vehicles must cooperate with a minimum of direct communication. We present a control strategy for a platoon of underwater vehicles that requires broadcast-only communications from a single vehicle within the platoon. Even as the size of the platoon increases, the bandwidth of required communication remains constant. Our emphasis is on the mathematical developments necessary ... |
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| Spatial Modulation in the Underwater Acoustic Communication Channel |
JUN 2000 |
|
| Authors:
Daniel B. Kilfoyle; WOODS HOLE OCEANOGRAPHIC INSTITUTION MA
|
| A modulation technique for increasing the reliable data rate achievable by an underwater acoustic communication system is presented and demonstrated. The technique, termed spatial modulation, seeks to control the spatial distribution of signal energy such that multiple parallel communication channels are supported by the single, physical ocean channel. Results from several experiments successfully demonstrate higher obtainable data rates and power throughput. Given a signal ... |
|
| SSC San Diego - The World Is Our Platform |
MAY 2000 |
7 pages |
| Authors:
Robert L. Wernli; SPACE AND NAVAL WARFARE SYSTEMS CENTER SAN DIEGO CA
|
| Technology is changing the future for the U.S. Navy, and Ocean Engineering will play a major role. In the past, navy research concentrated on platforms such as surface ships and submarines, but the future will be driven by communications between bases and platforms whether on shore, afloat, submerged, or in the air. Immediate access to tactical information will be critical for successful mission planning and execution, and much of this ... |
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| Multiple Tube Plasma Antenna |
05 OCT 1999 |
|
| Authors:
Theodore R. Anderson; Victor K. Choo; DEPARTMENT OF THE NAVY WASHINGTON DC
|
| An antenna is provided in which electromagnetic signals in the High Frequency and Super High Frequency hands are propagated utilizing ionized gas, or plasma. Energized electrodes ionize the gas and the plasma is confined within non-metallic coaxial tubes contained within a non-metallic pressure vessel. Electric field gradients are used to change the shape and density of the plasma to affect the gain and directivity of the antenna. The inner plasma ... |
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| Examination of Time-Reversal Acoustics in Shallow Water and Applications to Underwater Communications |
JUN 1999 |
|
| Authors:
Antonio A. Abrantes; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
|
| Time-varying multipath propagation is considered the most important difficulty in shallow underwater acoustic (UWA) communications. To compensate for the time variability of the channel, the receiver must use an adaptive algorithm for adjusting its parameters. At high symbol rates, intersymbol interference caused by multipath propagation requires large adaptive filters, increasing the computational complexity at the receiver end. This thesis presents a time-reversal acoustic technique (implemented with a phase-conjugated array of ... |
|
| Magellan II LFAl5 |
MAR 1999 |
6 pages |
| Authors:
Christopher W. Clark; CORNELL UNIV ITHACA NY
|
| Acoustic data from a horizontal line array deployed from the R/V Cory Chouest were analyzed for marine mammal sounds in order to assess the accuracy of Navy personnel in detecting and identifying whale vocalizations, and to determine whether there was any evidence of potential impact on whales from SURTASS LFA transmissions. Results were based on an analysis of 386 hours from the LFA-15 exercise, February and ... |
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Reports by Keyword(s)
UNDERWATER COMMUNICATIONS
