| Ambiguity Function Analysis for the Hybrid Mimo Phased-Array Radar (Postprint) |
Sep-2009 |
8 pages |
| Authors:
Muralidhar Rangaswamy; Daniel R Fuhrmann; J P Browning; MICHIGAN TECHNOLOGICAL UNIV HOUGHTON DEPT OF ELECTRICAL AND COMPUTER ENGINEERING
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 | The Hybrid MIMO Phased Array Radar, or HMPAR, is a notional concept for a multisensor radar architecture that combines elements of traditional phased-array radar with the emerging technology of Multiple-Input Multiple Output (MIMO) radar. A HMPAR comprises a large number, MP, of T/R elements, organized into M subarrays of P elements each. Within each subarray, passive element level phase shifting is used to steer transmit and receive beams in some ... |
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| Transition in Gas Turbine Engine Control System Architecture: Modular, Distributed, Embedded |
Aug-2009 |
79 pages |
| Authors:
Al Behbahani; Dennis Culley; Bill Mailander; Dewey Benson; Bruce Wood; Derek Weber; Bill Rhoden; Gary Hunter; Casey Carter; AIR FORCE RESEARCH LAB WRIGHT-PATTERSON AFB OH PROPULSION DIRECTORATE
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| Presentations from the Distributed Engine Control Working Group included: Vision and need for future turbine engine control; Implementation and technology challenges; High temperature electronics; Innovation and entry barriers. |
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| A Tutorial on EM-Based Density Estimation with Histogram Intensity Data |
01-Jun-2009 |
69 pages |
| Authors:
Phillip L Ainsleigh; NAVAL UNDERSEA WARFARE CENTER DIV NEWPORT RI DEPT OF SENSORS AND SONAR SYSTEMS
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| This report examines histogram estimation techniques in which intensity data are represented using a parameterized probability density function (PDF) model. It gives a high-level overview of histogram modeling, introducing the dominant issues and motivations, and then provides detailed mathematical developments of the histogram-based algorithms. |
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| A Method to Analyze Network-Centric Capabilities for Agile C2 for Force Sustainment Soldiers in Southwest Asia |
Jun-2009 |
43 pages |
| Authors:
Gregory A Miller; Natalie E Vanatta; Rachel E Goshorn; NAVAL POSTGRADUATE SCHOOL MONTEREY CA DEPT OF SYSTEMS ENGINEERING
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| The U.S. Army Chief Information Officer (CIO/G6) recognized potential communication and collaboration issues in performing C2 for Force Sustainment Soldiers working at Forward Operating Bases in Southwest Asia. The G6 commissioned a study to determine what network enabled capabilities would improve Logistics tasks in this area of operations. This paper outlines the methodology employed to identify and prioritize those gaps based on their impact on the efficacy of Transportation operations. ... |
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| Behavioural Indices of Central Auditory Processing |
Jun-2009 |
|
| Authors:
Sharon M van der Abel; Dan Werf; DEFENCE RESEARCH AND DEVELOPMENT TORONTO (CANADA)
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 | This research examined the effect of aging, gender, ear and practice on the outcomes of a battery of behavioural tests used in clinical practice to diagnose pathology of the central auditory system. The test battery included the Dichotic Digits Test, Duration Patterns Test, Frequency Patterns Test and Gaps-in-Noise Test. The ultimate goal was to determine whether such tests might be useful in diagnosing pathology of central origin in cases where ... |
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| Research Operations for Advanced Warfighter Interface Technologies |
Jun-2009 |
117 pages |
| Authors:
Timothy P Ryan; GENERAL DYNAMICS ADVANCED INFORMATION SYSTEMS DAYTON OH
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| Execution of the Research Operations for Advance Warfighter Interface Technologies (ROADWIT) contract required a broad range of technical expertise supporting the mission of the Human Effectiveness Directorate (711 HPW/RHC). The mission of 711 HPW/RHC is to develop science and technology that improves the effectiveness of human-human and human-machine interaction within the Air Force. General Dynamics' mission, in support of 711 HPW/RHC research, is to ensure that the human operator is ... |
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| High-Frequency Acoustic Billboard Array for High Spatial Resolution Measurements of the Ocean Sound Field |
31-Mar-2009 |
4 pages |
| Authors:
Gerald L D'Spain; SCRIPPS INSTITUTION OF OCEANOGRAPHY LA JOLLA CA MARINE PHYSICAL LAB
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| This DURIP/ONR project (N00014-04-1-0582) was to design and construct a 128-element, high-frequency (15 kHz design frequency) billboard array to be used in our High-Frequency/Mid-Frequency Passive Processing (HF/MF) program. |
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| Study of How Environmental Fluctuations Influence the Coherence of Acoustic Signals |
31-Mar-2009 |
9 pages |
| Authors:
Claire Debever; SCRIPPS INSTITUTION OF OCEANOGRAPHY LA JOLLA CA MARINE PHYSICAL LAB
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| This project supported the graduate studies and research of Claire Debever in the area of matched-field processing. The aim is to combine adaptive and coherent broadband methods to ultimately develop a robust matched-field processing technique well suited for practical applications in challenging environments. |
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| Flying Wing Autonomous Underwater Glider for Basic Research in Ocean Acoustics, Signal/Array Processing, Underwater Autonomous Vehicle Technology, Oceanography, Geophysics, and Marine Biological Studies |
31-Mar-2009 |
4 pages |
| Authors:
Gerald L D'Spain; SCRIPPS INSTITUTION OF OCEANOGRAPHY LA JOLLA CA MARINE PHYSICAL LAB
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| The objective of this specific project was to design and construct a new generation flying wing underwater glider, dubbed ZRay, based upon the experience developed over the past three years (2006-2008) of at-sea testing with XRay (under ONR grant N00014-04-1-0558). The new design developed during this project includes several innovations that significantly improve a Liberdade glider's persistence, passive sensing capability, and robustness |
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| Broadband Multichannel Source-Receive Nodes |
27-Mar-2009 |
13 pages |
| Authors:
William S Hodgkiss; SCRIPPS INSTITUTION OF OCEANOGRAPHY LA JOLLA CA MARINE PHYSICAL LAB
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| Two broadband multichannel source-receive nodes have been designed and fabricated for use in the investigation of both acoustic propagation perturbations caused by environmental fluctuations and acoustic data communications in the ocean. |
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| Exploitation of Environmental Complexity in Shallow Water Acoustic Data Communications |
27-Mar-2009 |
8 pages |
| Authors:
William S Hodgkiss; SCRIPPS INSTITUTION OF OCEANOGRAPHY LA JOLLA CA VISIBILITY LAB
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| Complexity of the channel is beneficial for time reversal communications. After multichannel combining, each user signal is processed with a single channel decision feedback equalizer (DFE) to remove any residual intersymbol interference (ISI) and compensate for channel fluctuations during the packet transmission. This same approach can be applied in a synthetic aperture context where multiple transmissions (separated spatially) substitute for multiple receive elements. As an alternative to the passive time ... |
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| Multi-Static Detection and Localization of Buried Targets using Synthetic Aperture Iterative Time-Reversal Processing |
18-Mar-2009 |
26 pages |
| Authors:
H C Song; Karim Sabra; W A Kuperman; W S Hodgkiss; SCRIPPS INSTITUTION OF OCEANOGRAPHY LA JOLLA CA MARINE PHYSICAL LAB
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| The objective of this project is to develop bi-static applications of the iterative time reversal techniques to focus along the ocean bottom. Iterative time-reversal provides a simple solution for self-adaptive focusing on strong reflectors (i.e. scattering targets) located on the ocean bottom without relying on predictive or modeling capabilities of the environment and of the target of interest. These robust focusing properties are crucial for mapping large and uncharted areas ... |
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| New Theory and Algorithms for Compressive Sensing |
06-Mar-2009 |
17 pages |
| Authors:
Richard G Baraniuk; RICE UNIV HOUSTON TX
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| In this project we expanded the field of compressive sensing in both theoretical and practical ways. We first demonstrated the information scalability of CS. We applied CS principles to analog-to-digital conversion, showing ADC can be accomplished on structured high rate signals with sub-Nyquist sampling. We introduced a smashed filter to perform statistical classification problems with a rate of measurements that corresponds to the problem structure, rather than bandwidth. Second, we ... |
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| Portable Ultrasound Imaging of the Brain for Use in Forward Battlefield Areas |
Mar-2009 |
21 pages |
| Authors:
Gregory T Clement; ULTRADIAGNOSTICS INC ATTLEBORO FALLS MA
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| Using ultrasound as a detection device in the body, including the brain, has been extensively investigated. Unfortunately, previous ultrasound-based methods on the brain have suffered from the severe distortion caused by the skull bone. The authors have recently developed a technique that allows ultrasound to propagate through the skull with significantly reduced distortion using a shear mode technique. The current project will develop a device for noninvasive identification of the ... |
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| Design and Development of a Single Channel RSNS Direction Finder |
Mar-2009 |
95 pages |
| Authors:
Jessica A Benveniste; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
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| This thesis carried out the design and development of a single channel Robust Symmetrical Number System (RSNS) virtual spacing direction finding (DF) system. This was based on previous work on a three-channel RSNS virtual spacing DF system. Various moduli sets were chosen and run through MATLAB simulations. The results showed unacceptably large errors at low signal-to-noise ratios (SNRs) for all sets. Large dynamic range moduli sets yielded relatively high errors ... |
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| Utilizing Microelectromechanical Systems (MEMS) Micro-Shutter Designs for Adaptive Coded Aperture Imaging (ACAI) Technologies |
Mar-2009 |
131 pages |
| Authors:
Mary M Ledet; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH GRADUATE SCHOOL OF ENGINEERING AND MANAGEMENT
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| The Air Force has long relied on surveillance for intelligence and strategic purposes. Most surveillance systems rely on a lensing system to acquire their images, most of which are in either the visible or infrared wavelengths. Because lensing systems can be expensive, obtrusive, or hard to maintain, researchers have designed adaptive coded aperture imaging (ACAI) as a replacement system. Coded aperture imaging(CAI) has been used in both the astronomical and ... |
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| A Short-Segment Fourier Transform Methodology |
Mar-2009 |
41 pages |
| Authors:
Andrew J Noga; AIR FORCE RESEARCH LAB ROME NY INFORMATION DIRECTORATE
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| A short-segment Fourier-transform methodology is introduced. This method addresses the problem of reduced frequency resolution associated with desirable decreases in data segment lengths for accomplishing spectral analyses of sampled signals and data sequences. The method is characterized by user-defined sampling of the continuous-valued discrete-time Fourier transform, superresolution in the frequency domain and allowance of Dirac delta functions associated with pure sinusoidal input data components. |
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| An Investigation Into the Feasibility of Using a Modern Gravity Gradient Instrument for Passive Aircraft Navigation and Terrain Avoidance |
Mar-2009 |
180 pages |
| Authors:
Marshall M Rogers; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH GRADUATE SCHOOL OF ENGINEERING AND MANAGEMENT
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| Recently, Gravity Gradient Instruments (GGIs) - devices which measure the spatial derivatives of gravity, have improved remarkably due to development of accelerometer technologies. Specialized GGIs are currently flown on aircraft for geological purposes in the mining industries. As such, gravity gradient data is recorded in flight and detailed gradient maps are created after post mission processing. These maps, if stored in a database onboard an aircraft and combined with a ... |
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| Low Probability of Intercept Waveforms via Intersymbol Dither Performance Under Multipath Conditions |
Mar-2009 |
77 pages |
| Authors:
Jonathan K Keen; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH GRADUATE SCHOOL OF ENGINEERING AND MANAGEMENT
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| This thesis examines the effects of multipath interference on Low Probability of Intercept (LPI) waveforms generated using intersymbol dither. This thesis expands on prior work by examining the effects of multipath interference on cooperative and non-cooperative receiver performance to assess the above method's effectiveness using a more realistic model of the physical transmission channel. The performance of a Minimum Mean Squared Error (MMSE) cooperative equalizer and a Constant Modulus Algorithm ... |
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| Synthesized Synchronous Sampling Technique for Bearing Damage Detection Preprint |
Mar-2009 |
18 pages |
| Authors:
Hai Qiu; Huageng Luo; George Ghanime; Melinda Van Der Hirz; Geo Merwe; AIR FORCE RESEARCH LAB WRIGHT-PATTERSON AFB OH MATERIALS AND MANUFACTURING DIRECTORATE
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| Differential bearing between the low-pressure turbine (LPT) shaft and high-pressure turbine (HPT) shaft is one of the most vulnerable parts in a turbo machinery engine. Yet, it is one of the most difficult parts to detect the damage signatures, because the signal to noise ratio at the regular sensor locations is usually low. In addition, the speed variations in both the LPT and the HPT can further deteriorate the damage ... |
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| Light Localization and Navigation in Optically-Induced Photonic Lattices |
25-Feb-2009 |
7 pages |
| Authors:
Zhigang Chen; SAN FRANCISCO STATE UNIV CA
|
| The primary objective of this project is to study light localization and routing in optically-induced photonic bandgap structures, and to promote education and research in optics and photonics at San Francisco State University, one of the national HBCU/MIs. We are happy to report that we made significant accomplishments on controlling light in nonlinear photonic lattices, and successfully completed this funded project. More than 30 scientific research papers have been published ... |
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| Design of Robust Adaptive Array Processors for Non-Stationary Ocean Environments |
20-Feb-2009 |
19 pages |
| Authors:
Kathleen E Wage; GEORGE MASON UNIV FAIRFAX VA
|
| The overall goal of this project is to design adaptive array processing algorithms that have good transient performance, are robust to mismatch, work with low sample support, and incorporate waveguide physics in a meaningful and robust way. To develop improved array processing algorithms for non-stationary environments, this project is investigating adaptive beam forming algorithms that can operate on a single-snapshot or a very limited number of snapshots. Spectral estimation methods, ... |
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| A Two-Dimensional Deoxyribonucleic Acid (DNA) Matrix Based Biomolecular Computing and Memory Architecture |
Feb-2009 |
25 pages |
| Authors:
Anthony Macula; Russell Deaton; Junghuei Chen; STATE UNIV OF NEW YORK AT ALBANY RESEARCH FOUNDATION
|
| The primary goal of this research was the development of an enabling technology for DNA computing. It focused on the development of two distinct DNA-based nanotechnologies, aqueous computing and DNA arrays. Once merged, these DNA-based nanotechnologies serve as a platform for a hybrid silicon-DNA computing architecture. The aqueous side is where the computing happens and the array side is where the results are preprocessed. The array information passes to an ... |
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| Advanced Conveyance Security Device System Scalability Assessment: Combined 802.15.4 and IP Network Simulation |
Feb-2009 |
22 pages |
| Authors:
Sarah M Lauff; Douglas S Hulbert; Ayax D Ramirez; Russ E Clement; Stephen L Childress; SPACE AND NAVAL WARFARE SYSTEMS CENTER PACIFIC SAN DIEGO CA ADVANCED TECHNOLOGY BRANCH (55430)
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| Space and Naval Warfare Systems Center Pacific (SSC Pacific) is conducting and documenting field tests, analysis and demonstrations with Sandia National Laboratories to investigate the capability of potential Advanced Conveyance Security Device (ACSD) technologies to meet container monitoring and communications performance thresholds needed for global implementation of the ACSD systems. This report demonstrates the capability of a commercially available network simulation package, and uses the star topology to model heterogeneous ... |
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| Embedded Meta-Material Antennas |
31-Jan-2009 |
21 pages |
| Authors:
Dennis W Prather; DELAWARE UNIV NEWARK
|
| With the dawn of the Digital Battlefield, a critical capability in the modern warfare environment is the miniaturization of electronic warfare signal and information processing systems. To realize such systems, the key is to miniaturize antennas that transmit and receive signals. In particular, by introducing reconfigurable antennas, one can combine multiple antennas operating at various frequency bands into a single aperture, which can provide significant miniaturization and flexibility to the ... |
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| Performance Limits and Design of MIMO for Sensor and Ad Hoc Wireless and Networks |
05-Jan-2009 |
8 pages |
| Authors:
Rick S Blum; LEHIGH UNIV BETHLEHEM PA DEPT OF COMPUTER SCIENCE AND ELECTRICAL ENGINEERING
|
| We have made excellent progress on studying appropriate signal processing and communication strategies for networks of dispersed nodes where each node may be equipped with a sensor. One area of focus has been on developing appropriate signal processing and communication strategies for networks which focus on target detection or hypothesis testing problems. There are many important military and non-military applications of this paradyme. In particular, hypothesis testing, often called signal ... |
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| The N456 Navigator System |
Jan-2009 |
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| Authors:
Lane J Abrams; WOODS HOLE OCEANOGRAPHIC INSTITUTION MA
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| The N456 Navigator has been developed to assist in Long Baseline (LBL) acoustic navigation. Its two basic functions are generation of acoustic signals, and receipt and timing of returns. When combined with the new dsnav software this becomes the basic component of an LBL navigation system. The principal motivation for this development was as a replacement for the Benthos 455 Acoustic Signal Processor and the Alvin's NavBox. The N456 is ... |
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| Mathematical Analysis of Signal Processing Capabilities of Wireless Networks |
Jan-2009 |
18 pages |
| Authors:
Zhi-Quan Luo; MINNESOTA UNIV MINNEAPOLIS DEPT OF ELECTRICAL AND COMPUTER ENGINEERING
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| The problem of distributed estimation/tracking/localization in a bandwidth/power constrained wireless sensor network is studied. Significant progress has been made on several fronts: i) Introduced the concept of estimation diversity in the context of distributed sensing and established its tradeoff with energy efficiency. |
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| Design and Development of Basic Physical Layer WiMAX Network Simulation Models |
Jan-2009 |
58 pages |
| Authors:
Bob Szeker; NEW TECHNOLOGIES INC KANATA (ONTARIO)
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| This report details and summarizes the work performed in developing computer simulation models for fixed and mobile WiMAX physical layers. The development was divided into 3 phases during which various simulation models of increasing complexity were produced. The models were coded using Matlab software. Emphasis was placed on developing source code in strict accordance with WiMAX standard specifications. The initial software models simulated a fixed WiMAX physical layer during which ... |
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| Prototype Sparse Arrays for 3D Sonar Imaging System |
Jan-2009 |
8 pages |
| Authors:
John Impagliazzo; Steven Kay; Alice M Chiang; Steven R Broadstone; NAVAL UNDERSEA WARFARE CENTER DIV NEWPORT RI
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| A three dimensional sonar imaging system is under development for use by Navy divers for mine-field reconnaissance and mine-hunting systems. These divers require a small, low power, lightweight acoustic imaging system with high resolution for examining and disposing of underwater ordinance. Sparse array technology is being investigated to develop a sonar requiring the minimal number of signal processing channels while maintaining the beamwidth and sidelobe structure required for high resolution ... |
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| Statistical Signal Processing for Demining: Continuation and Field Evaluation |
22-Dec-2008 |
14 pages |
| Authors:
Leslie M Collins; Peter A Torrione; DUKE UNIV DURHAM NC
|
| In this program, we investigated basic questions of interest to NVESD regarding landmine detection phenomenology, and developed algorithms for robust landmine detection for a variety of sensors, with primary focus on NIITEK radar-based sensors. We have developed a highly effective pre-screener algorithm that has been tested on several field sites, blind tests, and several offroad sites. The performance of the algorithm on the blind tests were outstanding, and in conjunction ... |
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| Efficient Implementation of Filtering and Resampling Operations on Field Programmable Gate Arrays (FPGAs) for Software Defined Radio (SDR) |
Dec-2008 |
79 pages |
| Authors:
Georgios Giannoulis; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
|
| In Software Defined Radios a good portion (or even the entirety) of the modulation and demodulation processes is performed in the digital domain. The data rate of the transmitted information is very important, since efficiency is a key requirement in real time implementations and cost increases considerably with the number of samples per second to be processed. In this thesis, we address the problem of efficient design of the resampling ... |
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| Multi-Static Radar Signal Processing-Improved Interference Rejection, Tracking and Discrimination |
Dec-2008 |
11 pages |
| Authors:
Richard Schneible; Russell Brown; Michael Wicks; Yuhong Zhang; Robert McMillan; STIEFVATER CONSULTANTS MARCY NY
|
| In a multi-static radar (MSR) the transmit/receive aperture is divided into a number of sub-apertures that can be placed in various locations relative to each other. These locations can be chosen to optimize the performance of the radar in terms of some specific task. Two multi-static approaches have been investigated: 1. Closely spaced apertures distributed aperture radar (DAR) 2. Widely spaced apertures Realizing the greater capability of MSR's requires unique ... |
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| Symmetric Gain Optoelectronic Mixers for LADAR |
Dec-2008 |
7 pages |
| Authors:
Neal Bambha; Stephen Drew; Nuri W Emanetoglu; Justin R Bickford; MAINE UNIV AT ORONO DEPT OF ELECTRICAL AND COMPUTER ENGINEERING
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| We are developing a symmetric gain optoelectronic mixer for chirped-AM laser detection and ranging systems (LADAR) operating in the eye-safe 1.55 micron wavelength range. Signal processing of a chirped-AM LADAR system is simplified if the photodetector in the receiver is used as an optoelectronic mixer (OEM). Adding gain to the optoelectronic mixer allows the following transimpedance amplifier's gain to be reduced, increasing bandwidth and improving the system's noise performance. The ... |
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| Bridging the Gap in Military Robotics (Combler le Fosse Existant dans le Domaine de la Robotique Militaire) |
Nov-2008 |
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| Authors:
NATO RESEARCH AND TECHNOLOGY ORGANIZATION NEUILLY-SUR-SEINE (FRANCE)
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| There appears to exist a gap between the ideas of the military on the use of ground robotics for their purposes and the technical possibilities offered by industry and research. In many cases the military are offered robots created by industry, but to a lesser degree robots developed to explicitly meet military needs. To bridge this gap, a NATO workshop was organised September 2004 in Bonn, attended by over 70 ... |
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| Expanding Coherent Array Processing to Larger Apertures Using Empirical Matched Field Processing |
30-Sep-2008 |
8 pages |
| Authors:
Frode Ringdal; Tormod Kvaerna; David B Harris; Steven J Gibbons; NORWEGIAN SEISMIC ARRAY (NORSAR) KJELLER
|
| The objectives of this project are: (1) To investigate the limits of empirical matched field processing and other coherent array detection and parameter estimation methods as receiver aperture size increases from a few kilometers to many hundreds of kilometers. (2) To investigate techniques for extending the geographical source-region footprint over which empirical matched field processing and other coherent calibrated methods apply. Under a previous contract, we demonstrated the ability of ... |
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| Semi-Empirical Yield Estimates for the 2006 North Korean Explosion |
30-Sep-2008 |
9 pages |
| Authors:
David H Salzberg; SCIENCE APPLICATIONS INTERNATIONAL CORP SAN DIEGO CA
|
| Science Applications International Corporation (SAIC) is testing a semi-empirical signal processing approach to estimate the yield of explosions. Under Air Force Research Laboratory contract FA8718-05-C-0019, SAIC developed a technique to combine the `truth' of empirical observation with the flexibility of synthetics to generate empirical filters that can be applied to the synthetic seismogram. Specifically, our approach is to design filters that transform the synthetic waveforms to match observed referenced waveforms. ... |
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| Multi-Array Detection, Association and Location of Infrasound and Seismo-Acoustic Events in Utah |
30-Sep-2008 |
10 pages |
| Authors:
Brian Stump; Relu Burlacu; Chris Hayward; Stephen J Arrowsmith; Il-Young Che; Gurpreet Singh; LOS ALAMOS NATIONAL LAB NM
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| The two main objectives of this work are to (1) develop an automated method for processing seismic and infrasound data from multiple seismo-acoustic arrays, and (2) to apply the method to a regional network of arrays for validation. The project involves development of automated techniques for detecting, associating, and locating infrasound signals at single and multiple arrays and then combining the processed results with similar automated procedures for seismic signals. ... |
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| Modeling and Simulation of a Non-Coherent Frequency Shift Keying Transceiver Using a Field Programmable Gate Array (FPGA) |
01-Sep-2008 |
125 pages |
| Authors:
Konstantinos Voskakis; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
|
| In this thesis, the principals of Software Defined Radio are demonstrated by implementing a Binary Frequency Shift Keying (BFSK) receiver-transmitter in a Field Programmable Gate Array (FPGA). After introducing the theory behind the Non- Coherent BFSK demodulation implemented at the receiver, the design of transmitter and receiver is illustrated. The design environment of choice is Mathworks Simulink and Xilinx System Generator, a dedicated library for Mathworks Simulink. The design is ... |
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| Advanced Beamformers |
Sep-2008 |
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| Authors:
Stergios Stergiopoulos; DEFENCE RESEARCH AND DEVELOPMENT TORONTO (CANADA)
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| The aim with this report is to bring together some of the recent theoretical developments on beamformers; and provide suggestions of how modern technology can be applied to the development of current and next generation ultrasound systems and integrated active and passive sonars. It will focus on the development of an advanced beamforming structure that allows the implementation of adaptive and synthetic aperture signal processing techniques in ultrasound systems and ... |
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| A Baum-Welch Algorithm for Noisy Vector Fields for Classification and Synthesis of Textures Using Non-Symmetric Half-Plane |
Aug-2008 |
6 pages |
| Authors:
Paul M Baggenstoss; NAVAL UNDERSEA WARFARE CENTER DIV NEWPORT RI
|
| In this paper we present a statistical model with a non-symmetric half-plane (NSHP) region of support for two-dimensional continuous-valued vector fields. It has the simplicity, efficiency, and ease of use of the well-known hidden Markov model (HMM) and associated Baum-Welch algorithms for time-series and other one-dimensional problems. At the same time, it is able to learn textures on a two-dimensional field. We describe a fast approximate forward procedure for computation ... |
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| A Comprehensive Web-Based Library of Marine Biological Sounds |
07-Jul-2008 |
6 pages |
| Authors:
Jack W Bradbury; CORNELL LAB OF ORNITHOLOGY ITHACA NY MACAULAY LIBRARY
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| This project funded the creation of the world's largest online reference collection of marine animal sounds at the Macaulay Library (Cornell Lab of Ornithology). Over a 6 year period, 5700 audio clips (1200 hours) of marine mammal and fish sound recordings were digitized, documented in an extensive metadata base, and made available for free online playback. Users can search the collection using a variety of criteria and either play back ... |
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| Classifier Design for Multi-aspect Low-Frequency Broadband Target Signatures |
25 JUN 2008 |
14 pages |
| Authors:
Lawrence Carin; Patrick Rabenold; SIGNAL INNOVATIONS GROUP INC DURHAM NC
|
| The early classification algorithms developed for the Low Frequency Broadband (LFBB) mine identification program were implemented using signal features that treat each target aspect independently. This approach results in a trained classifier that ignores any spatial correlation between sequential target responses. This motivated the design of a correlation-based kernel that combines the advantages of a discriminative approach and the sequential nature of the data. The resulting correlation kernel directly evaluates ... |
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| Wireless Cooperative Networks: Self-Configuration and Optimization |
15 JUN 2008 |
5 pages |
| Authors:
Liuqing Yang; FLORIDA UNIV GAINESVILLE DEPT OF ELECTRICAL AND COMPUTER ENGINEERING
|
| Distributed multi-input multi-output (MIMO) system is a promising architecture to provide reliable communications over spatially separated relaying nodes. In this paper, we will investigate the optimum resource allocation techniques in distributed MIMO systems, employing differential (de)modulation and various relaying protocols. Instead of limiting to energy optimization, we solve this problem via a two-dimensional energy and location optimization. Benefits of our resource optimization approaches are illustrated through extensive analysis and simulations. ... |
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| Wavelet-Based Signal Processing for Monitoring Discomfort and Fatigue |
Jun-2008 |
106 pages |
| Authors:
Cristhian Von Potes; Ricardo Borries; Cristiano J Miosso; TEXAS UNIV AT EL PASO
|
| Muscle fatigue involves both a decrease in the frequency and increase in the amplitude of a surface electromyographic (SEMG) signal. Muscle fatigue is also related to a decrease of the force impeding to reach the same initial level of the maximum voluntary contraction (MVC). To determine indices of muscle fatigue, a method is proposed to estimate both the instantaneous frequency (IF) and the instantaneous amplitude (IA) by decomposing the SEMG ... |
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| Integrated Sensor Systems for UAS |
01-Apr-2008 |
14 pages |
| Authors:
Mark C Patterson; Anthony Brescia; ADVANCED CERAMICS RESEARCH TUCSON AZ
|
| The miniaturization of sensors has in recent years led to the ability to provide multiple sensor operations from a single Unmanned Aircraft System (UAS) platform. Multiple UAS platforms can be synchronized to link devices from separate UAS platforms thus proving a powerful capability for data collection, while opening up interesting opportunities in the way data is retrieved and used. A range of new sensors being investigated will be discussed with ... |
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| Design Strategies to Mitigate Unsteady Forcing (Preprint) |
APR 2008 |
56 pages |
| Authors:
John P. Clark; AIR FORCE RESEARCH LAB WRIGHT-PATTERSON AFB OH PROPULSION DIRECTORATE
|
| The ability to predict accurately the levels of unsteady forcing on turbine blades is critical to avoid high-cycle fatigue failures. Further, a demonstrated ability to make accurate predictions leads to the possibility of controlling levels of unsteadiness through aerodynamic design. Several ingredients were essential to the success achieved in this study. First, judicious post-processing of CFD solutions was required to ensure that proper periodicity was achieved, and this was contingent ... |
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| Contrast Enhancement for Thermal Acoustic Breast Cancer Imaging via Resonant Stimulation |
01-Mar-2008 |
30 pages |
| Authors:
Jian Li; Mark Sheplak; Lou Cattafesta; Henry Zmuda; Huabei Jiang; Manuel Arreola; FLORIDA UNIV GAINESVILLE
|
| This research plans to develop enhanced contrast thermal acoustic imaging (TAI) technology for the detection of breast cancer by combining amplitude-modulated (AM) electromagnetic (EM) field excitation resonant acoustic scattering and advanced signal processing techniques. While EM-induced TAI possesses great promise, the thermal acoustic signals tend to be weak However when the tumor is excited into resonance via EM stimulation the effective acoustic scattering cross-section may increase by a factor in ... |
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| Signal Processing Technique to Remove Signature Distortion in ARL Synchronous Impulse Reconstruction (SIRE) Ultra-Wideband (UWB) Radar |
MAR 2008 |
22 pages |
| Authors:
Lam Nguyen; ARMY RESEARCH LAB ADELPHI MD SENSORS AND ELECTRON DEVICES DIRECTORATE
|
| ARL has designed and developed the SIRE UWB SAR radar in support of the U.S. Army vision for increased mobility, survivability, and lethality. The radar is based on time-domain wideband impulses. For this radar, ARL designed and implemented a data acquisition technique called Synchronous Impulse Reconstruction (SIRE) that allowed us to employ relatively slow ADC (40 MHz) to digitize wideband signals (>3000 MHz). However, the scheme assumed that the radar ... |
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| ELINT Signal Processing Using Choi-Williams Distribution on Reconfigurable Computers for Detection and Classification of LPI Emitters |
MAR 2008 |
104 pages |
| Authors:
Teresa L. O. Upperman; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
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| This thesis documents the use of the SRC-6 Reconfigurable Computer for use in analyzing low probability of intercept (LPI) signals using the Choi-Williams distribution. The SRC-6 is a reconfigurable computer manufactured by SRC Computers, Inc. which allows the user to tailor both the software and the hardware to a specific task. This increases the speed at which the task can be accomplished making it useful for applications in electronic intelligence ... |
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Reports by Keyword(s)
SIGNAL PROCESSING
