| Basics of SAR Polarimetry I |
01 FEB 2007 |
41 pages |
| Authors:
Wolfgang-Martin Boerner; UIC-ECE COMMUNICATIONS CHICAGO IL COMMUNICATIONS, SENSING AND NAVIGATION LAB
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 | A comprehensive overview of the basic principles of radar polarimetry is presented. The relevant fundamental field equations are first provided. The importance of the propagation and scattering behavior in various frequency bands, the electrodynamic foundations such as Maxwell's equations, the Helmholtz vector wave equation and especially the fundamental laws of polarization will first be introduced. The fundamental terms which represent the polarization state will be introduced, defined and explained. Main ... |
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| Advanced Polarimetric Concepts - Part 1 (Polarimetric Target Description, Speckle filtering and Decomposition Theorems) |
01 FEB 2007 |
31 pages |
| Authors:
Eric Pottier; Jong-Sen Lee; Laurent Ferro-Famil; UNIVERSITE DE RENNES 1 (FRANCE) INSTITUT ELECTRONIQUE TELECOMMUNICATION DE RENNES (IETR)
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| There is currently a great deal of interest in the use of polarimetry for radar remote sensing. In this context, different and important objectives are to classify Earth terrain components within a fully polarimetric SAR image and then extract physical information from the observed scattering of microwaves by surface and volume structures. The most important observable measured by such radar systems is the 3x3-coherency matrix. This matrix accounts for local ... |
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| Advanced Polarimetric Concepts - Part 2 (Polarimetric Target Classification) |
01 FEB 2007 |
41 pages |
| Authors:
Eric Pottier; Jong-Sen Lee; Laurent Ferro-Famil; UNIVERSITE DE RENNES 1 (FRANCE) INSTITUT ELECTRONIQUE TELECOMMUNICATION DE RENNES (IETR)
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| There is currently widespread interest in the development of radar sensors for the detection of surface and buried targets and the remote sensing of land, sea and ice surfaces. An important feature of electromagnetic radiation is its state of polarization and a wide range of classification algorithms and inversion techniques have recently been developed based on the transformation of polarization state by scattering objects. There are three primary ways in ... |
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| Evolution of the Department of Defense Millimeter and Microwave Monolithic Integrated Circuit Program |
FEB 2007 |
168 pages |
| Authors:
William C. Pittman; ARMY AVIATION AND MISSILE RESEARCH DEVELOPMENT ENG CTR REDSTONE ARSENA AL APPLIED SENSORS GUIDANCE AND ELECTRONICS DIRECTORATE
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| The Millimeter and Microwave Monolithic Integrated Circuits (MIMIC) program had its origins in the concern of the smart weapons community for the affordable production of millimeter wave missile seekers, but the broad-based applicability of the technology to radar, communications, countermeasures, and counter-countermeasures was recognized in the formulation of the program. The program was initiated in the turbulent 1980s during the period of high technology trade deficits (and the defense buildup) ... |
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| Advanced Propagation Model (APM) Version 2.1.04 Computer Software Configuration Item (CSCI) Documents |
FEB 2007 |
439 pages |
| Authors:
A. E. Barrios; W. L. Patterson; R. A. Sprague; SPACE AND NAVAL WARFARE SYSTEMS COMMAND SAN DIEGO CA
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| This document provides Version 2.1.04 Computer Software Configuration Item documents for the Advanced Propagation Model (APM). The APM calculates range-dependent electromagnetic system propagation loss and propagation factor within a heterogeneous atmospheric medium over variable terrain, where the radio-frequency index of refraction is allowed to vary vertically and horizontally. The first document specifies the functional requirements that are to be met by the APM CSCI. A discussion of the input software ... |
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| Classical Method for Deriving the Electromagnetic Propagation Equations for Double Negative Materials With Application for Antenna Design |
FEB 2007 |
28 pages |
| Authors:
Ira Kohlberg; KOHLBERG ASSOCIATES INC RESTON VA
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| We derive a system of propagation equations in a Double Negative (DN) material in a way that appears to differ from previous derivations although the end result is the same. Our derivation assumes the Poynting vector theorem applies, real materials always have some loss, epsilon(omega) and mu(omega) are obtained from real materials, and wave energy traveling in a specified direction must always be accompanied by a loss of energy in ... |
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| Continent-Wide Maps of Lg Coda Q Variation and Rayleigh-wave Attenuation Variation for Eurasia |
30 JAN 2007 |
50 pages |
| Authors:
Brian J. Mitchell; Lianli Cong; SAINT LOUIS UNIV MO
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| We present new maps of Lg coda Q and its frequency dependence at 1 Hz (Qo and eta, respectively) as well as Rayleigh-wave attenuation coefficients at 5, 10, 20 and 50 s across virtually all of Eurasia. Qo is relatively high, 700 or more, in most cratonic regons but is surprisingly low in the Arabian craton (300-450), the Siberian trap portion of the Siberian Platform (~450) and the Deccan trap ... |
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| Optimisation of Dallenbach Layers Using Real Materials |
JAN 2007 |
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| Authors:
P. Saville; DEFENCE RESEARCH AND DEVELOPMENT ATLANTIC DARTMOUTH (CANADA)
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 | In this paper multilayer Dallenbach absorbers were designed using the genetic algorithm optimisation routine and known material properties. The genetic algorithm was used to provide the global minimum solution to the reflectivity performance of the absorbers. The bandwidth and reflectivity of the absorber designs depend on the number of layers, layer composition and the layer order. Successful absorber designs are those that present an impedance gradient to the electromagnetic radiation. ... |
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| Detection of Frequency-Hopped Waveforms Embedded in Interference Waveforms with Noise |
Jan-2007 |
7 pages |
| Authors:
John Weber; Kyle Kowalske; Clark Robertson; Frank Kragh; Christopher Brown; NAVAL POSTGRADUATE SCHOOL MONTEREY CA DEPT OF ELECTRICAL AND COMPUTER ENGINEERING
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| Bandwidth usage has become more complex such that it is not uncommon that multiple signals of appreciable power may be present within the same bandwidth. The presence of multiple signals in addition to additive white Gaussian (AWGN) increases the difficulty of detecting frequency-hopped (FH) waveforms. This paper investigates the performance of an exponential-averaging based FH detection method in the presence of interfering signals and AWGN. The detection method provides an ... |
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| Extending Hyperspectral Capabilities with Dualband Infrared Focal Plane Arrays |
2007 |
11 pages |
| Authors:
Paul D. LeVan; John P. Hartke; Eustace L. Dereniak; Brian P. Beecken; AIR FORCE RESEARCH LAB KIRTLAND AFB NM SPACE VEHICLES DIRECTORATE
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| Dualband infrared focal plane arrays (FPA) were developed originally for multi-spectral imaging applications, where their advantages in compactness and band-to-band pixel registration, relative to conventional multispectral imagers, were recognized. As dualband FPA architecture is matured for quantum well and mercury cadmium telluride focal plane arrays, and becomes within the grasp of strained layer superlattice technology, applications in addition to multi-waveband imaging come to mind. In various hyperspectral applications that employ ... |
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| Network Beamforming Using Relays with Perfect Channel Information |
13-Dec-2006 |
35 pages |
| Authors:
Hamid Jafarkhani; Yindi Jing; CALIFORNIA UNIV IRVINE DEPT OF ELECTRICAL ENGINEERING AND COMPUTER SCIENCE
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| This paper is on beamforming in wireless relay networks with perfect channel information at relays, the receiver, and the transmitter if there is a direct link between the transmitter and receiver. It is assumed that every node in the network has its own power constraint. A two-step amplify-and-forward protocol is used, in which the transmitter and relays not only use match filters to form a beam at the receiver but ... |
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| Handheld, Broadband Electromagnetic UXO Sensor: Cost & Performance Report |
01-Dec-2006 |
38 pages |
| Authors:
Bill SanFilipo; Alex Oren; I J Won; GEOPHEX LTD RALEIGH NC
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| The broadband electromagnetic sensor improvement and demonstration undertaken in this project took the prototype GEM-3 and evolved it into an operational sensor with increased bandwidth and dynamic range, and enough memory and processing power to allow efficient data acquisition while decreasing the weight for ease of operation. Through this program, the GEM-3 has evolved from prototype into a fully operational, full-scale instrument, and the objective of this demonstration was to ... |
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| Scattering of Evanescent Acoustic Waves by Regular and Irregular Objects |
DEC 2006 |
19 pages |
| Authors:
Philip L. Marston; WASHINGTON STATE UNIV PULLMAN DEPT OF PHYSICS
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| Sound incident on the sea bottom at small grazing angles can produce acoustical evanescent waves in the sediment. The objective of this project was to describe the scattering by regular and irregular objects illuminated by acoustical evanescent waves in a simulated sediment. The theoretical developments were tested with laboratory scale experiments using a unique facility. The observables of interest in the scattering included (but were not limited to): (1) the ... |
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| Simulation of Organic Magnetic Resonance Force Microscopy Experiments |
DEC 2006 |
30 pages |
| Authors:
Doran D. Smith; ARMY RESEARCH LAB ABERDEEN PROVING GROUND MD
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| This report describes the numerical simulation of a series of proposed magnetic resonance force microscopy (MRFM) experiments on organic material. The simulation predicts the performance of a new MRFM system under construction at ARL for use on 2-D and 3-D proton containing samples. The SNR's and signal lineshapes of the new MRFM system are predicted using a geometry and experimental protocol well suited to the study of organic materials. The ... |
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| Total Ownership Cost Reduction Case Study: AEGIS Radar Phase Shifters |
DEC 2006 |
69 pages |
| Authors:
Wray W. Bridger; Mark D. Ruiz; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
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| The goal of this research is to provide a case study that captures the production and design processes and program management solutions used to reduce total ownership costs of AEGIS Radar Phase Shifters. Specifically, it will focus on the design and redesign of the SPY-1 radar phase shifter; a redesign that dramatically improved performance without increasing Average Procurement Unit Costs (APUC). The researchers will analyze various process-improvement projects (PIP) used ... |
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| Evaluation of ADCP Wave Measurements |
DEC 2006 |
71 pages |
| Authors:
Jeremy D. Boyd; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
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| Nearshore wave information is important to a variety of United States Navy operations in the littorals, including mine warfare, amphibious operations, small boat operations and special forces insertions. The objective of this thesis is to evaluate the accuracy of Teledyne RDI Acoustic Doppler Current Profilers (ADCP), in measuring wave height and direction spectra, so that the military can use these for routine wave measurements nearshore. This study uses ADCP data ... |
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| Low-Cost, High-Performance Analog Optical Links |
DEC 2006 |
120 pages |
| Authors:
Joelle Prince; William Burns; Edward Ackerman; Charles Cox; Harold Roussell; Frank Makrides; Michael Regan; PHOTONIC SYSTEMS INC BILLERICA MA
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| Photonic Systems, Inc. pursued the goal stated in the RF Lightwave Integrate Circuits' (RFLIC's) BAA ("...achieving a Vpi in the range of 0.1 to 0.5 Volts [to enable a link having] zero RF insertion loss with 1 - 10 mW of optical power available from conventional laser diode sources") on two parallel development paths. Collaborating with Sarnoff Corporation, Photonic Systems developed a Bipolar Cascade Laser that achieved a slope efficiency ... |
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| Cellular Automata: An Approach to Wave Propagation and Fracture Mechanics Problems |
DEC 2006 |
81 pages |
| Authors:
Selcuk Hosoglu; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
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| The Cellular Automata (CA) method is based on the idea that the macroscopic behavior of a system can be captured by using simple local rules running at a microscopic level. In other words, a system can be modeled by means of simple local rules that govern the behavior of the whole system. In this thesis a local CA rule set is introduced and a methodology is developed to model physical ... |
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| Joint Demodulation of Low-Entropy Narrowband Cochannel Signals |
DEC 2006 |
206 pages |
| Authors:
Timothy J. Meehan; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
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| Reception of one or more signals, overlapping in frequency and time with the desired signal, is commonly called cochannel interference. Joint detection is the optimal minimum probability of error decision rule for cochannel interference. This dissertation investigates the optimum approach and a number of suboptimum approaches to joint detection when a priori information based in fields, or sets of transmitted symbols, is available. In the general case the solution presents ... |
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| High-Cycle Life Testing of RF MEMS Switches |
DEC 2006 |
7 pages |
| Authors:
C. L. Goldsmith; D. I. Forehand; Z. Peng; J. C. Hwang; MEMTRONICS PLANO TX
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| RF MEMS capacitive switches capable of order of-magnitude impedance changes have demonstrated operating lifetimes exceeding 100 billion switching cycles without failure. In situ monitoring of switch characteristics demonstrates no significant degradation in performance and quantifies the charging properties of the switch silicon dioxide film. This demonstration lends credence to the mechanical robustness of RF MEMS switches. |
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| The Status and Future of the ICRF |
DEC 2006 |
7 pages |
| Authors:
A. L. Fey; NAVAL OBSERVATORY WASHINGTON DC
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| The International Celestial Reference Frame (ICRF) is currently defined by the radio positions of 212 extragalactic objects. Since its inception there have been two extensions to the ICRF. These extensions included revised positions of ICRF candidate and "other" sources, based on inclusion of additional observations, as well as positions of an additional 109 "new" sources. With continued applicable Very Long Baseline Interferometry (VLBI) observations and improvements in analysis a better ... |
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| Strain Mapping in Nanostructured Coatings by Synchrotron Radiation |
DEC 2006 |
12 pages |
| Authors:
Thomas Tsakalakos; Mark Croft; Rajendra Sadangi; Vijay Shukla; RUTGERS - THE STATE UNIV NEW BRUNSWICK NJ
|
| We report an Energy Dispersive X-ray Diffraction (EDXRD) method to determine the local strain field in a plasma sprayed Alumina-13% Titania ceramic coating. The measurements were carried out using high energy photons (100-300 KeV) on the X17B1 beamline at Brookhaven National Laboratory. The phase distribution of phases in the coatings produced from plasma spraying of micron size and agglomerated nanosize powder is described. |
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| Stochastic Resonance Investigation of Object Detection in Images |
DEC 2006 |
14 pages |
| Authors:
Daniel W. Repperger; Alan R. Pinkus; Julie A. Skipper; Christina D. Schrider; AIR FORCE RESEARCH LAB WRIGHT-PATTERSON AFB OH HUMAN EFFECTIVENESS DIRECTORATE
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| Object detection in images was conducted using a nonlinear means of improving signal to noise ratio termed "stochastic resonance" (SR). In a recent United States Patent application, it was shown that arbitrarily large signal to noise ratio gains could be realized when a signal detection problem is cast within the context of a SR filter. Signal-to-noise ratio measures were investigated. For a binary object recognition task (friendly versus hostile), the ... |
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| Computational Workloads for Commonly Used Signal Processing Kernels |
30 NOV 2006 |
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| Authors:
M. Arakawa; MASSACHUSETTS INST OF TECH LEXINGTON LINCOLN LAB
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| In the course of designing or evaluating signal processing algorithms, one often must determine the computational workload needed to implement the algorithms on a digital computer. The floating-point operation (flop) counts for real versions of the most common signal processing kernels are well documented. However, the flop counts for kernels operating on complex inputs are not as readily found. This report collects the flop count expressions for both real and ... |
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| Exploring Non-Thermal Radiofrequency Bioeffects for Novel Military Applications |
30 NOV 2006 |
13 pages |
| Authors:
Gale L. Craviso; Indira Chatterjee; NEVADA UNIV RENO
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| The research goal was to undertake a study to define radiofrequency/microwave (RF/MW) exposure parameters that produce non-them%al effects both on catecholamine release, using cultured adrenal chromaffin cells as an i,i vitro model system, and on skeletal muscle contraction, using intact skeletal muscle Strips. Major accomplishments included 1) implementation of experiments following completion of the design, characterization and construction both of a waveguide- based exposure system (0.75-1 GHz frequency range) and ... |
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| High-Performance Substrates for SERS Detection via Microphotonic Photopolymer Characterization and Coating With Functionalized Hydrogels |
26 NOV 2006 |
21 pages |
| Authors:
Orlin D. Velev; NORTH CAROLINA STATE UNIV AT RALEIGH
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| The goal of this research project in collaboration with ARL-Edgewood was to design, characterize and fabricate a new generation of stable and highly enhancing SERS substrates for sensors with continuous detection of chemical agents in water streams. We completed a detailed systematic study of hierarchically templated SERS substrates in thin films. In this task, convective assembly at high volume fractions was used to assemble gold nanoparticles into structured porous films ... |
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| Low-Profile Radiators in Non-Periodic Wideband Arrays |
22 NOV 2006 |
28 pages |
| Authors:
Jennifer T. Bernhard; Kiersten C. Kerby; Paul E. Mayes; Eric Michielssen; Garvin Cung; ILLINOIS UNIV AT URBANA-CHAMPAIGN MICRO AND NANOTECHNOLOGY LAB
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| This report details our research progress during the course of this grant. This report includes development of new wideband antenna elements, strategies for cost-effective random arrays using these elements, and supporting computational codes. First, a summary of the development and analysis of the new antenna element developed under this project is provided. Measured and simulated results show that this new element can provide a 3:1 bandwidth (using VSWR = 3 ... |
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| Polyomino Shaped Subarrays for Limited Field of View and Time Delay Control of Planar Arrays |
03 NOV 2006 |
10 pages |
| Authors:
R. J. Mailloux; S. G. Santarelli; T. M. Roberts; AIR FORCE RESEARCH LAB HANSCOM AFB MA
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| Phased array elements are often grouped into contiguous rectangular subarrays to reduce cost. This is done for two types of array applications. The first is for arrays that scan over only a limited sector, called limited field of view (LFOV) arrays. These use one phase shifter for each group of elements (subarray), and no phase shifters within the subarray. The second application is for arrays that scan over wide angles ... |
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| Artificial Ionospheric Turbulence and Radio Wave Propagation (Sura - HAARP) |
01 NOV 2006 |
164 pages |
| Authors:
Vladimir L. Frolov; RUSSIAN ACADEMY OF SCIENCES NIZHNY NOVGOROD RADIO PHYSICAL RESEARCH INST
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| This report results from a contract tasking Radio Physical Research Institute (NIRFI) as follows: The objectives of the project were: (i) integrated experimental, theoretical and computer simulation studies of non-linear plasma phenomena, produced in the upper ionosphere by powerful HF radiation and giving rise to plasma density irregularities with a wide range of cross-field (relatively to geomagnetic field lines) scales from centimeters to tens of kilometers, (ii) investigation of an ... |
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| Random Generation of Coherent Spin Wave Solitons From Incoherent Spin Waves |
01-Nov-2006 |
6 pages |
| Authors:
Mingzhong Wu; Pavol Krivosik; Carl E Patton; COLORADO STATE UNIV FORT COLLINS DEPT OF PHYSICS
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| This paper reports on the random generation of coherent envelope solitons from incoherent waves in a medium with an instantaneous nonlinearity, and specifically, in a magnetic thin film strip. One excites a propagating incoherent spin wave packet and observes the random appearance of spin wave envelope solitons from the propagating packet. The random solitons are as coherent as traditional envelope solitons, but both the peak amplitude and timing are random. ... |
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| Implementing a GPS Waveform Under the Software Communication Architecture |
NOV 2006 |
13 pages |
| Authors:
Alison Brown; Lynn Stricklan; David Babich; NAVSYS CORP COLORADO SPRINGS CO
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| SCA governs the structure and operation of software defined radios, enabling programmable radios to load waveforms, run applications, and network into an integrated system. Adherence to standards detailed in the SCA definition document allows hardware and software designers to know what equipment and programs to design. The SCA Hardware (HW) Framework tells the designer what minimum design specifications must be met by hardware devices. These specifications assure software written to ... |
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| Calibration and Verification Procedures at ARL for the Focus Microwaves Load Pull System |
NOV 2006 |
28 pages |
| Authors:
Benjamin D. Huebschman; ARMY RESEARCH LAB ADELPHI MD SENSORS AND ELECTRON DEVICES DIRECTORATE
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| When evaluating the performance of technologically innovative microwave devices, it is important to be able to validate the performance of the system performing the measurements. The theory behind the measurements used in recent Army Research Laboratory testing of the Gallium Nitride high electron mobility transistor devices is described. The verification of calibration used in the measurement is outlined in detail, including a metric by which the accuracy of the validation ... |
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| Comparison of Electromagnetic Simulation Results with Experimental Data for an Aperture-Coupled C-Band Patch Antenna |
NOV 2006 |
24 pages |
| Authors:
Steven Keller; William Coburn; Theodore Anthony; Chad Patterson; ARMY RESEARCH LAB ADELPHI MD SENSORS AND ELECTRON DEVICES DIRECTORATE
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| The Method of Moments, implemented in 2.5-dimensions (2.5-D) with the multilayer Green's Function, and the Finite Element Method, a fully three-dimensional (3-D) solution of Maxwell's equations, are two popular methods for antenna simulations. Commercial software implementing these two methods was used to simulate a single aperture-coupled patch antenna element. This effort was time limited so that a simple antenna was selected for which the antenna design, fabrication, and measurements could ... |
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| KOJAK: Scalable Semantic Link Discovery Via Integrated Knowledge-Based and Statistical Reasoning |
NOV 2006 |
53 pages |
| Authors:
Hans Chalupsky; UNIVERSITY OF SOUTHERN CALIFORNIA MARINA DEL REY INFORMATION SCIENCES INST
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| Link discovery (LD) is a new challenge in data mining whose primary concern is to identify strong links and discover hidden relationships among entities and organizations based on low-level, incomplete and noisy evidence data. Within this effort, USC/ISI addressed this challenge by developing a hybrid link discovery system called KOJAK that combines state-of-the-art knowledge representation and reasoning (KR&R) technology with statistical clustering analysis techniques from the area of data mining. ... |
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| A Simple Signal Processing Architecture for Instantaneous Radar Polarimetry |
NOV 2006 |
9 pages |
| Authors:
Stephen D. Howard; A. R. Calderbank; William Moran; PRINCETON UNIV NJ PROGRAM IN APPLIED AND COMPUTATIONAL MATHEMATICS
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| This paper describes a new radar primitive that enables instantaneous radar polarimetry at essentially no increase in signal processing complexity. This primitive coordinates transmission of distinct waveforms on orthogonal polarizations and applies a unitary matched filter bank on receive. This avoids the information loss inherent in single-channel matched filters. A further advantage of this scheme is the elimination of range sidelobes. |
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| Passive Synthetic Aperture Array Imaging at Millimeter Wave Frequencies using Novel Electro-optical Detection and Processing |
31 OCT 2006 |
39 pages |
| Authors:
Dennis W. Prather; Mark Mirotznik; DELAWARE UNIV NEWARK
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| In this effort we have designed, fabricated, and demonstrated a one-dimensional synthetic aperture imaging system for the passive imaging of millimeter waves (MMWs) using optical upconversion and correlation techniques. The advantage of this approach over alternate techniques is that the proposed system does not require expensive high-speed electronic detection and read out circuits and it is light enough to be used on UAV platforms. This technique eliminates the need for ... |
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| SHIMCAD Breadboard: Design and Characterization |
16 OCT 2006 |
35 pages |
| Authors:
Christoph R. Englert; David D. Babcock; John M. Harlander; NAVAL RESEARCH LAB WASHINGTON DC
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| This report covers the first phase of the Spatial Heterodyne Imager for Chemicals and Atmospheric Detection (SHIMCAD) project. The two goals of this phase were (1) to design and build a non-field-widened LWIR SHS breadboard interferometer with primarily off-the-shelf parts and using fixed angles and distances within the interferometer so that no post integration alignment is required and (2) to characterize the interferometer's wavelength calibration, phase distortion, and zero path ... |
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| Beam Divergence from an SMF-28 Optical Fiber |
06 OCT 2006 |
17 pages |
| Authors:
Jr. Kowalevicz Andrew M.; Frank Bucholtz; NAVAL RESEARCH LAB WASHINGTON DC
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| We present a calculation and experimental results using three different approaches for the spatial divergence of an optical beam exiting a standard, single-mode telecommunications-grade optical fiber (SMF-28) operating near 1550 nm wavelength. The analysis shows some pitfalls for a common imaging technique for determining beam width and shows good agreement with theory when the beam width measurement is performed using either a knife-edge or pinhole approaches. These results are important ... |
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| Empirical Corrections to Dipole Model |
OCT 2006 |
23 pages |
| Authors:
Jonathan Miller; SCIENCE APPLICATIONS INTERNATIONAL CORP (SAIC) ARLINGTON VA CENTER FOR SEISMIC STUDIES
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| We successfully demonstrated an empirical approach for correcting errors in the standard Dipole Model of EMI response. The Dipole Model is accurate for small targets at relatively deep burial depths but it breaks down for larger targets at shallower depths because of the interaction between the target body and the spatially non-uniform primary field. Our approach was to calculate this interaction numerically for a large set of specific target-sensor geometries ... |
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| Impulse Noise: Measurement Techniques and Hearing Protector Performance. Report on Scientific Exchange at the French-German Research Institute of Saint-Louis |
OCT 2006 |
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| Authors:
Ann Nakashima; Karl Buck; Pascal Hamery; Sebastien De Mezzo; Gilbert Brom; DEFENCE RESEARCH AND DEVELOPMENT TORONTO (CANADA)
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| Measurements of impulse noise and the performance of several hearing protection devices were done in Saint-Louis and Baldersheim, France at the French-German Research Institute of Saint- Louis (ISL) in August 2006. Hearing protector performance was evaluated using an acoustic test fixture that was designed by ISL. Impulse noises of peak levels from 110 to 190 dB were produced by detonation of explosives. The noise attenuation achieved by a Peltor communications ... |
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| BASE 04 Transmission Loss Measurement and Modelling |
OCT 2006 |
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| Authors:
C. Calnan; DEFENCE RESEARCH AND DEVELOPMENT ATLANTIC DARTMOUTH (CANADA)
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| A previous contract resulted in the addition of the ray theory program Bellhop to the reverberation inversion program BREVER. This was done to allow inversion of reverberation results calculated from acoustic data recorded during the BASE 04 trials. However tests with Bellhop using parameters from the BASE 04 site indicated shortcomings in that program. The current contract began with test runs of CASS, a potential Bellhop replacement for reverberation inversions. ... |
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| Differential Space-Time Modulation for Wideband Wireless Networks |
30 SEP 2006 |
7 pages |
| Authors:
Hongbin Li; STEVENS INST OF TECH HOBOKEN NJ
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| This project investigated differential modulation for broadband wireless communication systems equipped with multiple transmit antennas operating in frequency-selective channels. The objective was to provide full spatio-spectral diversity and coding gain at affordable decoding complexity without the burden of estimating the underlying space-time frequency-selective channel. The authors have developed two differential space-time modulation schemes tailored to frequency-selective channels. These schemes offer different trade-offs in dealing with time-selective versus frequency-selective fading channels. ... |
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| Remarks on the New 100-200 Mhz Receiver of the Solar Radio Observatory of the AIP at Tremsdorf Near Potsdam, Germany |
30 SEP 2006 |
9 pages |
| Authors:
Gottfried J. Mann; ASTROPHYSIKALISCHES INST (AIP) POTSDAM (GERMANY)
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| This report results from a contract tasking Astrophysical Institute Potsdam as follows: Grantee will upgrade radio spectrometers allow collection of CME signature data it the 693-741 MHz and 316-337 MHz frequency ranges. This data will then be analyzed and compared to CME data from satellite collection systems. Known CME data from the satellite systems will help researchers determine if CME signatures can be detected from radio astronomical methods alone, without ... |
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| Co-channel Interference Mitigation for Robust Coexistence of Frequency Hopped Networks |
30-Sep-2006 |
35 pages |
| Authors:
Xiangqian Liu; LOUISVILLE UNIV KY DEPT OF ELECTRICAL AND COMPUTER ENGINEERING
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| To meet the military's increased need for rapidly deployable communication solutions, wireless networks are becoming increasingly common within tactical environments. Frequency hopping (FH) is widely used for radio transmission in such networks due to its low probability of detection/interception. With the increasing deployment, multiple networks occupying overlapping frequency bands are likely to coexist in a physical environment, especially in tactical operations, emergency situations, or dense-populated areas. Consequently co-channel interference due ... |
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| Delta-Sigma UHF Digital Waveform Generator |
26 SEP 2006 |
19 pages |
| Authors:
Sukomal Talapatra; Jimmy O. Alatishe; Lawrence M. Leibowitz; NAVAL RESEARCH LAB WASHINGTON DC RADAR DIV
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| The Naval Research Laboratory (NRL) has developed and built a prototype UHF Digital Waveform Generator (DWG) based on the Delta-Sigma algorithm, which allows arbitrary waveform generation. It provides predicted low phase and spurious noise. Much of the design uses field programmable gate arrays (FPGAs) for single-bit digital waveform generation. Four filter topologies were initially considered, including cascade, hybrid, parallel, and transposed. The cascade and parallel forms were eliminated because they ... |
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| A 6-Port 60 GHz Coupler for an RN2 Beam Former |
15 SEP 2006 |
5 pages |
| Authors:
J. R. Reid; Richard T. Webster; AIR FORCE RESEARCH LAB HANSCOM AFB MA SENSORS DIRECTORATE
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| A 6-port coupler has been implemented for use in an RN2 beam former at 60 GHz. The coupler was synthesized to provide the appropriate magnitude and phase division and then realized using micro-machined TEM transmission lines. At 60 GHz. all signal paths of the coupler have a measured insertion loss less than 1.14 dB and a phase error of less than 3.8 degrees. |
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| Enhanced Vibrational Echo Correlation Spectrometer for the Study of Molecular Dynamics, Structures, and Analytical Applications |
10 SEP 2006 |
4 pages |
| Authors:
Michael D. Fayer; STANFORD UNIV CA
|
| Funds from a DURIP equipment grant were used to augment the ultrafast IR 2D vibrational echo spectrometer. The major improvement involved a new dual MOT array detector composed of two 32 x 1 element MCT IR detector arrays. The dual array makes it possible to improve signal-to-noise ratio in the heterodyne detection of the vibrational echo signal. To implement the revamping of the system, new optics to implement the two ... |
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| High-Order Accurate Particle-In-Cell (PIC) Methods on Unstructured Grids with Applications to Microwave Generation and Accelerator Modeling |
01 SEP 2006 |
8 pages |
| Authors:
Jan S. Hesthaven; BROWN UNIV PROVIDENCE RI DIV OF APPLIED MATHEMATICS
|
| A thoroughly validated, robust, and efficiently solver for the electromagnetics problem continues to be extended to provide a basic field solver for the EM-PIC problem. This has resulted in a first generation of a DG-FEM based PIC method on unstructured grids. The particle mover relies on high-order interpolation, efficient local search algorithms to locate the particles, and a level set approach to implement elastic/inelastic interactions with boundaries. Charge and current, ... |
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| Quantitative Robust Control Engineering: Theory and Applications |
01 SEP 2006 |
45 pages |
| Authors:
Mario Garcia-Sanz; UNIVERSIDAD PUBLICA DE NAVARRA PAMPLONA (SPAIN) DEPT DE AUTOMATICA Y COMPUTACION
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| This paper presents a summary of the main concepts and references of the Quantitative Feedback Theory (QFT). It is a frequency domain engineering method to design robust controllers. It explicitly emphasizes the use of feedback to simultaneously reduce the effects of model plant uncertainty and to satisfy performance specifications. QFT highlights the trade-off (quantification) among the simplicity of the controller structure, the minimization of the cost of feedback, the existing ... |
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| Fundamentals of Signal Processing for Phased Array Radar |
01 SEP 2006 |
23 pages |
| Authors:
Ulrich Nickel; FGAN-FHR RESEARCH INST FOR HIGH FREQUENCY PHYSICS AND RADAR TECHNIQUES WACHTBERG (GERMANY)
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| This section gives a short survey of the principles and the terminology of phased array radar. Beamforming, radar detection and parameter estimation are described. The concept of subarrays and monopulse estimation with arbitrary subarrays is developed. As a preparation to adaptive beam forming, which is treated in several other sections, the topic of pattern shaping by deterministic weighting is presented in more detail. |
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Radiofrequency Wave Propagation
