| Stealing the Sword: Limiting Terrorist Use of Advanced Conventional Weapons |
2007 |
|
| Authors:
James Bonomo; Giacomo Bergamo; David R. Frelinger; IV Gordon John; Brian A. Jackson; RAND CORP SANTA MONICA CA
|
 | This book examines one manifestation of the general technical competition between terrorist groups and security organizations: the balance between the potential use by terrorists of advanced conventional weapons and the responses available to deter or counter them. Use of the term "advanced conventional weapons" is inclusive and broad: any new or unusual conventional weaponry developed for ordinary military forces. All weaponry is obviously designed to do damage, but new design ... |
|
| 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. ... |
|
| Airborne Hyperspectral and Satellite Multispectral Imagery of the Mississippi Gulf Coast Region |
DEC 2006 |
93 pages |
| Authors:
Lars O. Lone; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
|
| The Compact Airborne Spectrographic Imager (CASI) and the satellite Moderate Resolution Imaging Spectroradiometer (MODIS) provide detailed information about the environment U.S. Naval forces choose to operate in. In recent years environmental conditions have been a driving factor in preventing the detection of underwater objects like mines. Suspended sediments are an environmental condition of interest. Remote sensors provide an opportunity to detect suspended sediments in a region prior to the commencement ... |
|
| 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 ... |
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| 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 ... |
|
| Australian DefenceScience. Volume 13, Number 4, Summer |
Jan-2006 |
|
| Authors:
DEFENCE SCIENCE AND TECHNOLOGY ORGANISATION CANBERRA (AUSTRALIA)
|
| CONTENTS: Giving longer life to T56 engines - An international group of research partners is carrying out fatigue testing on the turbine section of Rolls-Royce T56 engines to extend the declared safe operating lives of this component beyond previously accepted limits. Unlocking the mind of Hercules - The Hercules C-130J was created with deep-sighted powers of intelligence, like those of its godly namesake, but, as DSTO discovered, these strengths were ... |
|
| Prediction of Instantaneous Currents in San Diego Bay for Naval Applications |
JUN 2004 |
72 pages |
| Authors:
Albert E. Armstrong; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
|
| Naval operations are highly dependent upon environmental conditions that can either adversely affect successful completion or hinder the safety of personnel. Each warfare community has defined environmental thresholds and operating limits that restrict the execution of any intended maneuver. As the warfare environment continues to shift from open ocean to the littoral, environmental prediction and modeling efforts of shallow water surroundings need to be developed to support these operations. A ... |
|
| Australian DefenceScience. Volume 12, Number 3, Spring |
Jan-2004 |
|
| Authors:
DEFENCE SCIENCE AND TECHNOLOGY ORGANISATION CANBERRA (AUSTRALIA)
|
| CONTENTS: Enhancing cartography with digital mapping - DSTO is exploring the latest in digital technologies to enhance cartographic materials. Autonomous UAV flight a world first - Autonomous, Intelligent Agent-controlled flight was achieved by an unmanned aerial vehicle (UAV). This flight demonstrated both in-flight Intelligent Agent control of the aircraft and fully autonomous mission selection capabilities. Missile countermeasures from flares to lasers - Major breakthroughs in laser design have led to ... |
|
| Real-Time Characterization of Mine Scour Burial at the Martha's Vineyard Coastal Observatory |
2004 |
7 pages |
| Authors:
Michael D. Richardson; Edward F. Braithwaite III; Sean Griffin; John Bradley; Carl T. Friedrichs; NAVAL RESEARCH LAB STENNIS SPACE CENTER MS MARINE GEOSCIENCES DIV
|
| Mine burial by scour was measured in real-time using two cylindrical instrumented mines connected to a shore-based facility at the Martha's Vineyard Coastal Observatory (MVCO). Data on mine movement (heading, pitch, and roll), scour pit geometry, percent burial, and environmental processes responsible for scour burial, including significant wave height, period, and tidal height were analyzed daily and presented on the NRL web site (http://www7430.nrlssc.navy. mil/bblp/mine/realtimedata). Scour pits developed in response ... |
|
| A Probabilistic Approach for Mine Burial Prediction |
2004 |
9 pages |
| Authors:
Costin Barbu; Philip Valent; Michael Richardson; Andrei Abelev; Nathaniel Plant; TULANE UNIV NEW ORLEANS LA DEPT OF COMPUTER SCIENCE
|
| Predicting the degree of burial of mines in soft sediments is one of the main concerns of Naval Mine CounterMeasures (MCM) operations This is a difficult problem to solve due to uncertainties and variability of the sediment parameters(i.e. density and shear strength) and of the mine state at contact with the seafloor (i.e. vertical and horizontal velocity, angular rotation rate and pitch angle at the mudline). A stochastic approach is ... |
|
| Underwater Weapon System Having a Rotatable Gun |
08 DEC 2003 |
14 pages |
| Authors:
Thomas J. Gieseke; DEPARTMENT OF THE NAVY WASHINGTON DC
|
| This patent application discloses an underwater weapon system having a rotating gun system mounted in a vehicle housing. The gun system includes a gun and ammunition sealed within a waterproof housing with the gun muzzle protruding from the housing. The gun system is rotatable relative to the first and second halves of the housing, while the housing can be maneuvered to rotate through a plane of rotation of the gun ... |
|
| "Sea Swat": A Littoral Combat Ship for Sea Base Defense |
DEC 2003 |
389 pages |
| Authors:
Robert Echols; Constance Fernandez; Rodrigo Cabezas; Aziz Kurultay; Wilfredo Santos; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
|
| Unlike past conflicts, which were characterized by major naval battles in the open ocean, present day threats are mostly associated with rogue nations and terrorist cells. These threats may strike at unsuspected times and locations. The United States Navy may operate from a Sea Base that protects power ashore through the use of surface and air assets. These assets must transit from the Sea Base in the blue water through ... |
|
| Motion Model Development for Very Shallow Water/Surf Zone Crawler |
11 JUN 2003 |
13 pages |
| Authors:
William C. Littlejohn; NAVAL SURFACE WARFARE CENTER PANAMA CITY FL
|
| The Very Shallow Water/Surf Zone (VSW/SZ) environment presents a challenging problem to Mine Countermeasures (MCM) operations conducted in military operations involving amphibious landings. Present tactics involve human swimmers and present a risky and time-consuming scenario. There are Unmanned Autonomous Vehicle (UAV) systems under development that will replace the human swimmers in VSW/SZ MCM operations. One of these systems is an Unmanned Ground Vehicle (UGV), commonly known as a crawler. The ... |
|
| Evaluation and Quantification of Randomness in Free-Fall Trajectory of Instrumented Cylinders |
26 MAR 2003 |
12 pages |
| Authors:
A. V. Abelev; P. J. Valent; N. G. Plant; K. T. Holland; NAVAL RESEARCH LAB STENNIS SPACE CENTER MS
|
| As a part of a field experiment designed to contribute to the Navy's effort to improve its capability to model and predict depth of burial of antiship mines in mud seafloors, the trajectory, velocity and orientation of a 1,100-kg cylinder were observed during 21 free fall trials in a field setting. Extreme values and distribution of linear and angular velocity components as well as orientation throughout the water column and, ... |
|
| The Dynamics of Cobble in and Near the Surf Zone |
SEP 2002 |
38 pages |
| Authors:
Don L. Boyer; Harindra J. Fernando; Sergey I. Voropayev; ARIZONA STATE UNIV TEMPE DEPT OF MECHANICAL AND AEROSPACE ENGINEERING
|
| This research was driven by the need of the Navy to improve mine countermeasures in support of joint littoral warfare, for which a key paradigm is to locate a clear or low mine- and obstacle-density path. To accomplish this goal, it is imperative that one be able to predict the behavior of mines in shallow water under a variety of coastal-ocean conditions. A laboratory experimental program, coupled with theoretical modeling, ... |
|
| Rim of the Pacific (RIMPAC). Programmatic Environmental Assessment |
JUN 2002 |
236 pages |
| Authors:
DEPARTMENT OF THE NAVY WASHINGTON DC
|
| RIMPAC is a multinational, sea control/power projection fleet exercise that has been performed biennially for the last 30 years. The purpose of RIMPAC is to implement a selected set of exercises that is combined into a sea control/power projection fleet training exercise in a multi-threat environment. RIMPAC exercises also demonstrate the ability of a multinational force to communicate and operate in simulated hostile scenarios. RIMPAC 2002 will be the eighteenth ... |
|
| Loitering Behaviors of Autonomous Underwater Vehicles |
JUN 2002 |
84 pages |
| Authors:
Douglas L. Williams; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
|
| In multi-vehicle mine hunting operations, it will be necessary at times for one vehicle to loiter at some point while gathering communications of data from other vehicles. The loitering behaviors of the ARIES Autonomous Underwater Vehicle have never been completely defined. The track that the vehicle chooses to maintain station while circling around one specific point for an extended period of time may be sometimes random and unpredictable, unless defined ... |
|
| Process for the Development of Image Quality Metrics for Underwater Electro-Optic Sensors |
APR 2002 |
9 pages |
| Authors:
Jr. Taylor James S.; Brett Cordes; Sam Osofsky; Ann Domnich; COASTAL SYSTEMS STATION PANAMA CITY FL
|
| Electro-optic identification "EOID" sensors have been demonstrated as an important tool in the identification of bottom sea mines and are transitioning to the fleet. These sensors produce two and three-dimensional images that will be used by operators to make the all-important decision regarding use of neutralization systems against sonar contacts classified as mine-like. The quality of EOID images produced can vary dramatically depending on system design, operating parameters, and ocean ... |
|
| Inferring Bottom Acoustic Properties from AN/SQQ-32 Sonar Reverberation Data in Order to Reduce False Targets in Bottom/Buried Mine Detection |
APR 2002 |
11 pages |
| Authors:
Henry H. Howell; Robert H. Bourke; James H. Wilson; J. M. Null and; Josette Fabre; FLEET NUMERICAL OCEANOGRAPHIC CENTER MONTEREY CA
|
| Bottom/sub bottom geoacoustic properties must be determined to high spatial resolution in order to reduce false targets for bottom/buried mine detection. Inversion techniques (ITs) are used to infer bottom geoacoustic properties using AN/SQQ-32 beam reverberation level (RL) time series data acquired in Rhode Island Sound in February 1993. A technique was developed wherein the deviation of the RL for an individual ping and beam from an area-wide average RL is ... |
|
| Demonstration of Surf Zone Crawlers: Results from AUV Fest 01 |
APR 2002 |
13 pages |
| Authors:
Chuck Bernstein; Mark Connolly; Mitch Gavrilash; Dan Kucik; Stan Threatt; NAVAL SURFACE WARFARE CENTER PANAMA CITY FL
|
| A key element in minimizing the risks of an amphibious assault is the ability to search and map the surf zone for mines and obstacles. The Office of Naval Research is sponsoring the development of an autonomous, bottom-crawling vehicle to investigate its applications in searching and clearing potential landing zones. In October 2001, AUV Fest 01 was held in Gulfport, Mississippi, where the current state of development of these vehicles ... |
|
| Hyperspectral Imaging for Intelligence, Surveillance, and Reconnaissance |
AUG 2001 |
10 pages |
| Authors:
David Stein; Jon Schoonmaker; Eric Coolbaugh; SPACE AND NAVAL WARFARE SYSTEMS CENTER SAN DIEGO CA
|
| This paper highlights SSC San Diego contributions to the research and development of hyperspectral technology. SSC San Diego developed the real-time, onboard hyperspectral data processor for automated cueing of high-resolution imagery as part of the Adaptive Spectral Reconnaissance Program (ASRP), which demonstrated a practical solution to broad area search by leveraging hyperspectral phenomenology. The authors explain how the DARPA ASRP successfully demonstrated the capability to detect military targets of interest ... |
|
| Naval Mine Warfare. Operational and Technical Challenges for Naval Forces |
2001 |
212 pages |
| Authors:
NATIONAL RESEARCH COUNCIL WASHINGTON DC NAVAL STUDIES BOARD
|
| U.S. naval forces are organized, trained, and equipped to engage in the full spectrum of military operations in the deep sea, the littorals, or inland. Yet today, sea mines in the hands of hostile forces are a growing threat to mobility, as evidenced in the Gulf War. To meet the threat of the proliferation and ever increasing sophistication of sea mines, the Department of the Navy has adopted an integrated ... |
|
| Creation of Dolphin-Like Spectrum Filters Through the Use of Evolutionary Programming |
SEP 2000 |
31 pages |
| Authors:
D. A. Helweg; D. S. Houser; P. W. Moore; SPACE AND NAVAL WARFARE SYSTEMS CENTER SAN DIEGO CA
|
| A type of self-optimizing computer algorithm, called evolutionary programming, was used to create a number of models of the dolphin ear. The models consisted of a series of overlapping bandpass filters that varied in sensitivity and bandpass region and were distributed across the range of dolphin hearing. The evolutionary program iteratively varied the shape, number, and distribution of filters in each model and optimized the acoustic ... |
|
| Underwater Acoustic Imaging: A Simulation Program and Related Theory |
APR 2000 |
|
| Authors:
David G. Blair; Stuart D. Anstee; AERONAUTICAL AND MARITIME RESEARCH LAB MELBOURNE (AUSTRALIA)
|
| To aid in the design of a high-resolution sonar (range and transverse resolution approaching 1 mm), a program, POINTSPR, was produced. POINTSPR predicts the image obtained from an active acoustic imaging system with a spherical projector, the target being modelled by a small number of point objects. The waveforms available include chirps and short tonebursts. The receiving elements available include a point and a square piston. A wide variety of ... |
|
| Sediment Sound Speed and Critical Angle Estimations Derived from In SituAcoustic Measurements |
FEB 2000 |
40 pages |
| Authors:
A. Maguer; W. L. Fox; H. Schmidt; E. Bovio; SACLANT UNDERSEA RESEARCH CENTRE LA SPEZIA (ITALY)
|
| Understanding the basic physics of sound penetration into ocean sediments is essential to the design of sonar systems which can detect, localize, classify, and identify buried objects. The sediment sound speed is a crucial parameter as the ratio of sound speed at the water-sediment interface determines the critical angle. Sediment sound speed is typically measured from core samples using high frequency (100's of kHz) pulsed ... |
|
| Naval Strategy During the American Civil War |
APR 1999 |
54 pages |
| Authors:
David J. Murphy; AIR WAR COLL MAXWELL AFB AL
|
| The objective of the research project is to examine how the Union and Confederate naval strategies and new naval technologies affected the conduct of the American Civil War. With regard to the Union Navy's strategy, the effectiveness of the blockade, Western River Campaign, and amphibious operations were examined. Discussions on the Union blockade also touch on the effectiveness on Confederate blockade runners. The Confederate strategies of using privateers and commerce ... |
|
| HeO2 CUMA Repetitive Dive Table Trials - Series 2 and 3 |
OCT 1998 |
|
| Authors:
Ronald Y. Nishi; Mark L. Kessler; DEFENCE AND CIVIL INST OF ENVIRONMENTALMEDICINE DOWNSVIEW (ONTARIO)
|
| The Canadian Underwater Minecountermeasures (MCM) Apparatus (CUMA) is a self-contained, semi-closed circuit breathing apparatus in service with the Canadian Forces (CF) for diving on underwater mines to a depth of 81 metres of seawater (msw) using a mixture of helium and oxygen (HeO2). Decompression tables for use with the CUMA include no-decompression, surface decompression with oxygen, and in-water oxygen decompression tables. DCIEM/EDU has been tasked to develop and test repetitive ... |
|
| Coastal Benthic Boundary Layer (CBBL) Research Program |
01 SEP 1998 |
375 pages |
| Authors:
Michael D. Richardson; NAVAL RESEARCH LAB STENNIS SPACE CENTER MS SEAFLOOR SCIENCES DIRECTORATE
|
| The Coastal Benthic Boundary Layer (CBBL) Special Research Program is a 5-year Office of Naval Research study that addressed the physical characterization and modeling of benthic boundary layer processes and the impact these processes have on seafloor structure, properties and behavior. This final report is a summary of the results compiled and published from FY92 through FY98. Quantitative physical models of the benthic boundary layer were tested in a series ... |
|
| Coastal Benthic Boundary Layer (CBBL) Research Program: A review of the fourth year |
01 SEP 1998 |
175 pages |
| Authors:
Michael D. Richardson; NAVAL RESEARCH LAB STENNIS SPACE CENTER MS MARINE GEOSCIENCES DIV
|
| The Coastal Benthic Boundary Layer (CBBL) Special Research program is a 5-year Office of Naval Research study that addressed the physical characterization and modeling of benthic boundary layer processes and the impact these processes have on seafloor structure, properties and behavior. The report is a summary of the results compiled and published during the fourth year of the program. Quantitative physical models of the benthic boundary layer are being tested ... |
|
| Surface Warfare. Mainstreaming, Mine Warfare. May/June 1998, Vol. 23, No. 3 |
JUN 1998 |
48 pages |
| Authors:
DEPUTY CHIEF OF NAVAL OPERATIONS (SURFACE WARFARE) WASHINGTON DC
|
| Contents include: Think or Sink - 21st Century Mine Warfare; The Naval Mine Threat to U.S. Surface Forces; Shaping the Battlespace: Organic Mine Countermeasures; Offensive Mining: A True Force Multiplier; The History of Mining; Mine Warfare - Enabling Power Projection in the Littorals; Maneuver Warfare and Mine Countermeasures; Surf Zone Technology: Enabling Operational Maneuver from the Sea; and, Conquering the VSW Environment. |
|
| Omnidirectional Ultrasonic Microprobe Hydrophone |
03 MAR 1998 |
|
| Authors:
Mark B. Moffett; James M. Powers; Dmitry Chizhik; Timothy B. Straw; DEPARTMENT OF THE NAVY WASHINGTON DC
|
| An omnidirectional ultrasonic microprobe hydrophone is disclosed. Applications include underwater mine detection, explosive shock testing, high wave number measurements, medical imaging, and therapeutic systems. The apparatus includes at least two lead zirconate titanate (PZT) pressure sensing elements having a plurality of columnar voids formed therein. The pressure sensing elements are deposited on a metallic or nonmetallic substrate which provides mechanical support for the microprobe hydrophone. Electrical connection to the pressure ... |
|
| The Applicability of Scaling Laws to Underwater Shock Tests |
NOV 97 |
|
| Authors:
lloyd Hammond; David Saunders; AERONAUTICAL AND MARITIME RESEARCH LAB MELBOURNE (AUSTRALIA)
|
| The applicability and limitations of classical scaling relationships are reviewed in relation to an AMRL investigation into the structural response of air backed plates to far field underwater explosions. It is intended that this investigation will determine the effects of charge size and disposition and a range of structural parameters on the structural response of submerged, air backed plates. |
|
| Air-Delivered Ordnance Explosive Mine and Obstacle Clearance Method |
26 AUG 1997 |
|
| Authors:
Felipe A. Garcia; Robert C. Woodall Jr; DEPARTMENT OF THE NAVY WASHINGTON DC
|
| A method for air delivery of ordnance and clearing of explosive mines and obstacles from a navigable sea channel includes the step of providing quantities of ordnance adapted to survive impact with land and sea and prolonged immersion in sea water and to arm in response to air flow pressure and then detonate in response to receiving a preselected signal transmitted to the ordnance from a standoff location. The method ... |
|
| A Discrete Digital Filter for Forward Prediction of Seaway Elevation Response |
MAR 1997 |
83 pages |
| Authors:
Anthony L. Simmons; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
|
| The Autonomous Underwater Vehicle (AUV) must be able to operate in various shallow water sea state conditions. In order to have a precise navigation and steering system, and efficiently place charges on underwater mines, the AUV must be able to sense and overcome hydrodynamic forces which are caused by waves. This thesis establishes a model of sea state conditions based on spectral analysis, and uses the model to predict future ... |
|
| Proceedings of the Technology and the Mine Problem Symposium, 18-21 November 1996, Naval Postgraduate School, Monterey, California. Volume I of II |
NOV 96 |
713 pages |
| Authors:
Albert M. Bottoms; Ellis A. Johnson; Barbara Honegger; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
|
| Major topics of this symposium are (1) The Challenge, (2) Operational Requirements and Perspectives, (3) Operational Environments and Threats, (4) Landmines and Humanitarian Demining, (5) Progress in Autonomous Systems for Mine Warfare, and (6) Countering Mines on Land. |
|
| Finite Difference Modelling of Scattering by Objects in the Seabed |
JUL 96 |
45 pages |
| Authors:
J. A. Fawcett; J. L. Grimbergen; SACLANT UNDERSEA RESEARCH CENTRE LA SPEZIA (ITALY)
|
| In this report we describe the theory and some implementation issues of a finite difference code used at SACLANT Centre. In particular, we consider the modelling of attenuation and the excitation of a remote incident field by using Huygen's sources. A series of comparisons of finite difference results with analytical results is performed. The report concludes with a series of computations of scattering of a generalized plane wave from a ... |
|
| Ship Survivability Enhancement Program: Management of the Program |
JUL 96 |
|
| Authors:
J. S. Howe; DEFENCE SCIENCE AND TECHNOLOGY ORGANIZATION CANBERRA (AUSTRALIA)
|
| The Ship Survivability Enhancement Program (SSEP) was devised to generate scientific data in research areas related to the survivability of ships and crews against attack from modern weapons. The experiments were concerned with electronic radiation, fire, smoke, exploding missile warheads, and limpet mines. Damage control and fire fighting methods were also studied. This report describes the considerable planning and management measures required to satisfy all of the constraints imposed by ... |
|
| Omnidirectional Ultrasonic Microprobe Hydrophone. |
29 MAY 1996 |
24 pages |
| Authors:
Mark B. Moffett; DEPARTMENT OF THE NAVY WASHINGTON DC
|
| An omnidirectional ultrasonic microprobe hydrophone is disclosed. Applications include underwater mine detection, explosive shock testing, high wave number measurements, medical imaging, and therapeutic systems. The apparatus includes at least two lead zirconate titanate (PZT) pressure sensing elements having a plurality of columnar voids formed therein. The pressure sensing elements are deposited on a metallic or nonmetallic substrate which provides mechanical support for the microprobe hydrophone. Electrical connection to the pressure ... |
|
| Short Range Lateral Variability of Seabed Properties (With Some Notes on Larger Scale Features) Near Port Hedland, W.A |
MAY 96 |
|
| Authors:
P. J. Mulhearn; DEFENCE SCIENCE AND TECHNOLOGY ORGANIZATION CANBERRA (AUSTRALIA)
|
| The spatial variability of seabed sediment properties over short ranges is investigated, and it is found that, at least for sands, sediment grain size varies within a factor of square root of 2 over distances of order 100 m. Evidence is then presented that this sediment variability, found off Port Hedland, is similar to that at many other locations around the world. Hence for acoustic backscatter and mine burial models ... |
|
| Experimental Investigation of a High Resolution Sonar |
MAR 96 |
|
| Authors:
Lim C. Huat; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
|
| This thesis investigated a laboratory synthetic aperture sonar designed to test the algorithms and techniques needed to detect, classify and identify minelike objects. Previous synthetic aperture sonar work at NPS achieved 5 cm range resolution and 1 cm azimuth resolution. This thesis developed a pulsed, frequency modulated, synthetic aperture sonar that achieved range and azimuth resolutions of about 1 cm. The processed images clearly reveal targets with a high degree ... |
|
| Selected Geotechnical Properties of a Calibration Test. Buried Explosives Against Shallow Targets. |
15 DEC 1995 |
86 pages |
| Authors:
William B. Sawyer; Kingsley H. McCrocklin; Michael W. Lambert; Conrad S. Kennedy; Lafayette G. Maynard; NAVAL RESEARCH LAB STENNIS SPACE CENTER MS
|
| This report characterizes the geotechnical properties of a grout material used as a testbed for the Defense Nuclear Agency sponsored project, Buried Explosives Against Shallow Water Targets (BEAST), a calibration test. The BEAST research program was designed to model the behavior of explosion shock waves in gassy littoral marine sediments and the effects on a ship passing over an exploding mine buried in such sediments. The grout material was chosen ... |
|
| NPS High Resolution Synthetic Aperture Sonar |
DEC 95 |
114 pages |
| Authors:
Joseph D. Welter; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
|
| This thesis investigated the use of synthetic aperture techniques to achieve a long effective aperture, high resolution, imaging sonar. The approach included a full simulation of the system using the MATLAB programming environment that provided a model for developing six data processing algorithms and a working 25KHz, 1 m baseline, air medium synthetic aperture sonar. The six azimuthal processing techniques included: (1) a normal, real aperture, (2) an unfocussed synthetic ... |
|
| Buried Object Detection Using Surface Waves |
SEP 95 |
64 pages |
| Authors:
William F. Stewart; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
|
| The goal of this thesis is to evaluate the use of surface waves to detect buried objects. The source used to generate the surface waves was a three element phased array controlled by LabVIEW visual instruments. This research included developing a source and receiver, evaluating attenuation and azimuthal dependence of the surface wave propagation, detection using scattering within a tank of sand, and using the three element array to beamform ... |
|
| Determination of Naval Medium Speed Diesel Engine Air Exhaust Emissions and Validation of a Proposed Estimation Model |
MAY 95 |
196 pages |
| Authors:
Agnes M. Mayeaux; NAVAL ACADEMY ANNAPOLIS MD
|
| Steady state marine diesel engine exhaust emissions are being reviewed by the Environmental Protection Agency for possible regulation. In anticipation of future regulation, the United States Navy is developing appropriate emissions models for naval vessels. Actual emissions data from a U. S. Navy ship is necessary to provide checkpoints for the models. A procedure for collecting this data from an U. S. Navy ship with medium speed main propulsion diesels ... |
|
| Detection of Buried Nitrogen Rich Materials. |
25 APR 1995 |
|
| Authors:
Han S. Uhm; DEPARTMENT OF THE NAVY WASHINGTON DC
|
| Fast neutrons from a moving source are thermalized by travel through water to a soil embedded body of nitro- gen-rich material causing emission of gamma rays there- from Emitted gamma rays are detected at a location adjacent the neutron source for measurement of radiation energy from which location of nitrogen-rich materials in the soil is mapped, based on a predetermined signature energy level of the measured radiation. (AN) ... |
|
| Effects of Case Thickness on the Performance of Underwater Mines |
JAN 95 |
|
| Authors:
D. A. Jones; E. D. Northeast; DEFENCE SCIENCE AND TECHNOLOGY ORGANIZATION CANBERRA (AUSTRALIA)
|
| The effect of case thickness on the performance of underwater mines was investigated both experimentally and computationally using 10 kg charges of H6. The charges were cylindrical in shape and surrounded by either 6 mm or 12 mm thick steel casing. Two bare charges were also fired. Analysis of the experimental pressure transducer records showed that casing thickness had no effect on peak pressure in the far field, but resulted ... |
|
| A Mine Search Algorithm for the Naval Postgraduate School Autonomous Underwater Vehicle |
DEC 94 |
102 pages |
| Authors:
Rodrigues Neto; Jose Augusto; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
|
| This thesis develops, implements and tests a mine search algorithm for the Naval Postgraduate School Autonomous Underwater Vehicle (Phoenix). The vehicle is 72 inches long and displaces 400 pounds. Its maneuvers are performed using two propellers and four thrustem. It contains two embedded computer systems. The algorithm directs the autonomous search of a specified area mapping all obstacles and computing an estimate of the cumulative probability of detection. The algorithm ... |
|
| Mines in the Surf Zone: A Proposed Breaching Concept |
SEP 94 |
72 pages |
| Authors:
Matthew M. Aylward; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
|
| This thesis addresses the threat that mines in the surf zone (ten foot curve to the high water mark) pose to Operational Maneuver From The Sea. Additionally, problems presented by minefields beginning at the high water mark and extending inland are reviewed. Effectiveness of notional minefields consisting of tilt rod and pressure fused anti-tank mines are modeled as a planar Poisson process. The delivery of the assault echelon (a Marine ... |
|
| Experimental Investigation into the Dynamic Response of Two DOF Tuned Deck Simulator for Shock Qualification of Shipboard Systems |
JUN 94 |
94 pages |
| Authors:
Timothy V. Flynn III; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
|
| The explosive shock created by the underwater explosion of a mine or torpedo in close proximity to a surface ship can severely threaten the combat capability and survivability of the ship. MEL-S-901D specifics the shock test procedures and acceptance criteria for all shipboard systems that must resist high impact mechanical shock. While the U.S. Navy's Medium-weight Shock Machine with its standard equipment mounting fixture can subject a combat systems component ... |
|
| Iran's Security Dilemma |
JUN 94 |
128 pages |
| Authors:
Dale R. Davis; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
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| Since the fall of Mohammed Reza Shah in 1979, the Islamic Republic of Iran has remained politically isolated from the United States and the West. After eight years of brutal war with Iraq, Iran has embarked on a major effort to rebuild its devastated military. A major element of its military reconstruction has been the acquisition of advanced weapons systems with strategic applications, such as long-range bombers, submarines, advanced underwater ... |
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UNDERWATER MINES
