| High-frequency Radar Cross Section (RCS) Approximation of a Thin Dielectric Spherical Shell |
Jul 2012 |
14 pages |
| Authors:
Geoffrey H Goldman; Frank J Crowne; ARMY RESEARCH LAB ADELPHI MD
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 | The high-frequency radar cross section (RCS) of a thin-filmed dielectric sphere in the far-field was approximated using a model based on two thin parallel dielectric plates. The results were compared to a solution developed by Andreasen based upon simplified boundary conditions. The models were used to estimate the RCS of a balloon with a diameter of 1 m. There was good agreement between the two methods. The RCS of the ... |
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| Remote Nondestructive Evaluation of Composite-Steel Interface by Acoustic Laser Vibrometry |
01 Jun 2012 |
74 pages |
| Authors:
II Emge Timothy J; MASSACHUSETTS INST OF TECH CAMBRIDGE
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| Composite materials are increasingly being used in both civil and ship structures. In particular, fiber reinforced polymer (FRP) composites are being utilized. FRP materials are most often employed to reinforce aging or damaged portions of civil structures. On naval vessels, FRP materials are incorporated to reduce weight, particularly up high, and to reduce radar cross section, thereby increasing stealth capability. In both cases of FRP use, it is usually in ... |
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| Nearshore Sea Clutter Measurements from a Fixed Platform |
Apr 2012 |
30 pages |
| Authors:
Erin E Hackett; Anne M Fullerton; Craig F Merrill; Thomas C Fu; NAVAL SURFACE WARFARE CENTER CARDEROCK DIV BETHESDA MD
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| This report describes a set of experiments performed in support of ONR's Environmental Sensing and Motion Forecast (ESMF) Program. The goal of the experiments was to obtaindata to evaluate the ability of low-grazing angle radars to provide near-field, nearreal time sea state data suitable for enabling a high-fidelity ship control system to control ship motion during Sea Basing ship-to-ship logistic operations in Sea State (SS) 4 and below. More specifically, ... |
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| Certified Reduced Basis Method for Electromagnetic Scattering and Radar Cross Section Estimation |
18 Nov 2011 |
33 pages |
| Authors:
Yanlai Chen; Jan S Hesthaven; Yvon Maday; Jeronimo Rodriguez; Xueyu Zhu; BROWN UNIV PROVIDENCE RI DIV OF APPLIED MATHEMATICS
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| We study nontrivial applications of the reduced basis method (RBM) for electromagnetic applications with an emphasis on scattering and the estimation of radar cross section (RCS). The method and several extensions are explained with two examples with different characteristics. Parameters that are allowed to vary within the model include frequency, incident angle and measurement angle as well as the geometry of the scatterers. With appropriate applications of the empirical interpolation ... |
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| Analysis of Transient Electromagnetic Scattering from an Overfilled Cavity Embedded in an Impedance Ground Plane |
Sep 2011 |
138 pages |
| Authors:
Robert S Callihan; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF ENGINEERING AND MANAGEMENT
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| We consider the transient, or time-domain, scattering problem of a two-dimensional overfilled cavity embedded in an impedance ground plane. This problem is a significant advancement from previous work where more simplified boundary conditions were used, which can limit the number of applications. This research supports a wide range of military applications such as the study of cavity-like structures on aircraft and vehicles. More importantly, this research helps detect the biggest ... |
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| Design Considerations for Nonlinear Scattering |
Sep 2011 |
16 pages |
| Authors:
Christian Fazi; Frank Crowne; Marc Ressler; ARMY RESEARCH LAB ADELPHI MD SENSORS AND ELECTRON DEVICES DIRECTORATE
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| Renewed interest in harmonic and multitone radar has motivated design efforts based on the standard approach found in the radar literature, i.e., the classical radar equation. In this report, we show that such approaches can be problematic in determining the correct power budget requirements for detecting a nonlinear target, and that it is necessary to examine the differences of a linear versus nonlinear target cross-section. |
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| An Approach to Minimizing Probe Array/Target Interactions for Near Field Scattering Measurements |
13 MAY 2011 |
27 pages |
| Authors:
John K. Schindler; SOLID STATE SCIENTIFIC CORP NASHUA NH
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| We describe an effort to reduce the time required for near field scattering measurements by using an array of near field probes to replace the single probe that is conventionally used. An array of near field probes introduces technical problems. Coupling between the array and the scattering body may introduce errors in the near field measurements by perturbing the plane wave induced currents on the body. Mutual coupling between the ... |
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| Monostatic and Bistatic HF Radar Cross Section Analysis of Large Vessels Using FEKO |
APR 2011 |
40 pages |
| Authors:
Symon K. Podilchak; ROYAL MILITARY COLL OF CANADA KINGSTON (ONTARIO)
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| Monostatic and bistatic Radar Cross Sections (RCS) of Canadian Coast Guard Ship Teleost and cargo-container vessel named Bonn Express are simulated using FEKO commercial electromagnetic simulation software. A good agreement is achieved between the simulated values and the measured values supplied by DRDC Ottawa, at the radar frequency of 4.1 MHz. With confidence in these FEKO models, the effect of pitch, roll and freighter loading was then investigated to account ... |
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| A Scattering Center-Based Prediction Method for Shadowing and Two-Body Interactions |
13 DEC 2010 |
7 pages |
| Authors:
Joshua L. Wilson; Brian W. Rybicki; Lea E. Johnson; Douglas M. Koltenuk; MASSACHUSETTS INST OF TECH LEXINGTON LINCOLN LAB
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| The electromagnetic interaction between two closely-spaced objects can have a significant impact on the total radar cross section. In this paper, we present a simple approximate method for modeling the two-body interaction by adjusting scattering centers to account for shadowing and diffraction phenomenon. The problem is simplified by replacing the shadowed object with discrete ideal isotropic scatterers corresponding to the object's scattering center model. By applying reciprocity, the Green's function ... |
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| A Technique for Real-Time Shadowing Adjustment of RCS Scattering Center Models |
01 DEC 2010 |
11 pages |
| Authors:
Joshua L. Wilson; Brian W. Rybicki; Lea E. Johnson; Douglas M. Koltenuk; MASSACHUSETTS INST OF TECH LEXINGTON LINCOLN LAB
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| A method has been developed to adjust Radar Cross Section (RCS) scattering models for two-body effects, particularly shadowing. The method described here involves using the near field scattering solution of one object to apply two-body corrections to another. By assuming that the second object can be represented by a known set of point scatterers, the fields at these scattering centers are used to calculate the adjusted RCS in the presence ... |
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| Alternative Methods to Standby Gain Scheduling Following Air Data System Failure |
Sep-2009 |
261 pages |
| Authors:
Matthew W Coldsnow; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH DEPT OF AERONAUTICS AND ASTRONAUTICS
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| The United States Air Force has advanced fighter aircraft that lose the ability to operate in a large portion of their operating flight envelope when an air data system failure is experienced. These aircraft are reverted to a fixed set of standby-gains that limit their maneuverability, degrade handling qualities, and increase susceptibility to departure. The purpose of this research was to determine if three alternative methods of standby-gain-scheduling could provide ... |
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| Modeling and Simulation Architecture for Studying Doppler-Based Radar with Complex Environments |
26-Mar-2009 |
78 pages |
| Authors:
Nicholas J Amato; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH GRADUATE SCHOOL OF ENGINEERING AND MANAGEMENT
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| This research effort develops a hybrid large-scale modeling and simulation framework that defines the requirements for a program to evaluate radar-aircraft-turbine-clutter interactions. Wind turbines and other moving structures can interfere with a radar's ability to detect moving aircraft because radar returns from turbines are comparable to those from slow flying aircraft. This interference can lead to aircraft collisions or crashes, reducing the safety for air traffic. Two radar applications, INSSITE ... |
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| RF Stealth (Or Low Observable) and Counter- RF Stealth Technologies: Implications of Counter- RF Stealth Solutions for Turkish Air Force |
Mar-2009 |
161 pages |
| Authors:
Serdar Cadirci; NAVAL POSTGRADUATE SCHOOL MONTEREY CA DEPT OF INFORMATION SCIENCES
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| This thesis will examine the evolution of stealth, with a focus on RF low observables, and the counter technologies to detect RF stealth or low observable aircraft, the reasons why an air force needs such technologies, advantages and disadvantages of these assets, and the latest developments in the area. While low observable technologies have been around for nearly half a century, they are still secretive in nature and sensitive. This ... |
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| Covert, Intelligent, and Spectrally-Efficient MIMO-Based Noise Radar Networks |
31-Jan-2009 |
158 pages |
| Authors:
Ram M Narayanan; Wiriyanto Darsono; Kyoung-Deuk Kim; Wei-Jen Chen; Qihe Pan; Shrawan C Surender; PENNSYLVANIA STATE UNIV UNIVERSITY PARK OFFICE OF SPONSORED PROGRAMS
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| The following tasks were accomplished: (1) Distributed adaptive beamforming using noise waveforms: The use of multiple radars for characterizing the radar cross section (RCS) of the target was investigated, and the RCS enhancement was quantified. A framework for inducing orthogonality in sequences and in polarization was developed to differentiate signals from various transmitters. Generalized Likelihood Ratio Test (GLRT) and Tapped Delay Line (TDL) beamforming were integrated. (2) RF tag approaches: ... |
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| Terahertz Backscattering Behavior of Various Absorbing Materials |
Jan-2009 |
13 pages |
| Authors:
C Wu; A J Gatesman; L DeRoeck; T Horgan; R H Giles; W E Nixon; MASSACHUSETTS UNIV LOWELL SUBMILLIMETER-WAVE TECH LAB
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| The Submillimeter-Wave Technology Laboratory (STL) at the University of Massachusetts Lowell has investigated the electromagnetic scattering behavior of various broadband absorbers. Several absorbing materials were tested in a compact radar range operating at a center frequency of 160 GHz. The polarimetric radar cross section was measured at elevation angles from 15 to 75 . In addition to the backscattering behavior, the normal incidence transmittance of the materials was evaluated. |
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| Multi-Input Multi-Output (MIMO) Radar - Diversity Means Superiority |
15-Oct-2008 |
6 pages |
| Authors:
Jian Li; FLORIDA UNIV GAINESVILLE DEPT OF ELECTRICAL AND COMPUTER ENGINEERING
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| A multiple-input multiple-output (MIMO) radar uses multiple antennas to simultaneously transmit several linearly independent waveforms. It also uses multiple antennas to receive the reflected signals. It has been shown that by exploiting this waveform diversity, MIMO radar can overcome performance degradations caused by radar cross section (RCS) fluctuations, achieve flexible spatial transmit beampattern designs, provide high-resolution spatial spectral estimates, and significantly improve the parameter identifiability. The MIMO radar can be ... |
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| Design and Implementation of an Active Calibration System for Weather Radars |
01-Sep-2008 |
177 pages |
| Authors:
Jason M Phillips; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
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| Pulsed weather radars can be used to depict meteorological conditions such as rainfall rate and wind velocity. These quantities are calculated from measurements of reflectivity, mean radial velocity and velocity spread using echo signal samples from weather targets. These radar measurements derive from modified radio frequency (RF) echo signal parameters, including amplitude, frequency and phase, returned to the radar from the weather target. RF scattering and propagation effects modily echo ... |
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| A Level Set Based Geometrical Eulerian Approach to Computing High Frequency Radar Cross Sections and Multiphase Semiclassical Limits of the Schrodinger Equation |
30-Jun-2008 |
5 pages |
| Authors:
Stanley Osher; LEVEL SET SYSTEMS INC PACIFIC PALISADES CA
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| Wave propagation in the high frequency regime can be simplified using the geometrical optics approximation. We obtained an eikonal approximation for the phase and transport equations for the amplitude. The general strategy used to find the phase is to solve for its level sets, called wave fronts. This same strategy works to compute semiclassical solutions of Schrodinger's equation, which is the main topic we studied here. Traditional obstacles faced in ... |
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| Remote Station User's Guide |
MAY 2008 |
30 pages |
| Authors:
John T. Clark; ARMY RESEARCH LAB ADELPHI MD
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| A transmitter that responds to an input signal (transponder) has been designed at the Ka Band frequency range. The transponder is further enhanced to simulate a moving target by returning a signal with an artificial Doppler frequency and power level commensurate with that of a particular Radar Cross Section (RCS). The RF architecture is described first, followed by a detailed derivation of simulated RCS and then a complete step by ... |
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| Validation of Xpatch Computer Models for Human Body Radar Signature |
MAR 2008 |
28 pages |
| Authors:
Traian Dogaru; Calvin Le; ARMY RESEARCH LAB ADELPHI MD SENSORS AND ELECTRON DEVICES DIRECTORATE
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| This technical report compares the radar signatures of a human body as computed by the Finite Difference Time Domain (FDTD) and Xpatch modeling techniques. Our main purpose is to validate the Xpatch (approximate) models with an exact electromagnetic solver (FDTD), We achieve this by comparing the radar cross section (RCS), range profiles and synthetic aperture radar (SAR) images of the human body, as computed by the two methods. This work ... |
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| Validation of Ship Signatures in Envisat ASAR AP Mode Data using AISLive: Data Acquisition, Processing, and Analysis Results |
MAR 2008 |
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| Authors:
Paris W. Vachon; John Wolfe; DEFENCE RESEARCH AND DEVELOPMENT CANADA OTTAWA (ONTARIO)
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 | Ships appear in synthetic aperture radar (SAR) ocean imagery as bright targets against the ocean clutter background. Envisat Advanced SAR (ASAR) Alternating Polarization (AP) mode data acquisitions over the Strait of Dover and the Strait of Gibraltar, two high-density shipping regions with Automatic Identification System (AIS) coverage via AISLive, have provided a large database of validated ship signatures. For each validated ship signature, several metrics were computed including the clutter ... |
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| Wind Farms and Radar |
JAN 2008 |
21 pages |
| Authors:
Michael Brenner; Shelly Cazares; Michael J. Cornwall; Freeman Dyson; Douglas Eardley; Paul Horowitz; Darrell Long; Jeremiah Sullivan; John Vesecky; Peter J. Weinberger; MITRE CORP MCLEAN VA JASON PROGRAM OFFICE
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| As part of its 2008 Winter Study, JASON was asked by the Department of Homeland Security (DHS) to review the current status of the conflict between the ever-growing number of wind-turbine farms and air-security radars that are located within some tens of miles of a turbine farm. |
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| Computer Models of the Human Body Signature for Sensing Through the Wall Radar Applications |
SEP 2007 |
56 pages |
| Authors:
Traian Dogaru; Lam Nguyen; Calvin Le; ARMY RESEARCH LAB ADELPHI MD
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| This technical report presents numerical simulations of the human body radar signature, with application to sensing through the wall (STTW) scenarios. We utilize the Finite Difference Time Domain (FDTD) modeling technique to compute the electromagnetic scattering from realistic human body models. We analyze the radar cross section (RCS) of the human body in different configurations as a function of aspect angle, frequency, and polarization, drawing important conclusions in terms of ... |
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| Wirelessly Networked Digital Phased Array: Analysis and Development of a Phase Synchronization Concept |
SEP 2007 |
88 pages |
| Authors:
Micael Grahn; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
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| The ongoing research of a wirelessly networked aperstructure digital phased array (WNADPA) at NPS has investigated the possibility of using a distributed opportunistic array for radar, where array elements are placed at any available area of the ship structure. This could give an array that is as large as the ship itself, with 360 degrees coverage. It has advantages in the areas of survivability and adaptability, and the profile of ... |
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| Technical Note on Scale Conversion for the Synchronous Impulse Reconstruction (SIRE) Radar |
JUL 2007 |
18 pages |
| Authors:
Kenneth Ranney; Lam Nguyen; Anders Sullivan; ARMY RESEARCH LAB ADELPHI MD SENSORS AND ELECTRON DEVICES DIRECTORATE
|
| This technical note describes a calibration method used to convert measurements obtained with the U.S. Army Research Laboratory synchronous impulse reconstruction (SIRE) radar from an integer scale to an absolute, radar cross section (RCS) scale. The required RCS reference point is obtained from highly accurate solutions of Maxwell's equations for a modeled reference target and scene. Electrical characteristics of this modeled target and scene are carefully selected to match those ... |
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| Technical Note on Scale Conversion for the Synchronous Impulse Reconstruction (SIRE) Radar, a Second Method |
JUL 2007 |
18 pages |
| Authors:
Kenneth Ranney; Lam Nguyen; Anders Sullivan; ARMY RESEARCH LAB ADELPHI MD SENSORS AND ELECTRON DEVICES DIRECTORATE
|
| This technical note describes a calibration method used to convert measurements obtained with the U.S. Army Research Laboratory (ARL) synchronous impulse reconstruction (SIRE) radar from an integer scale to an absolute, radar cross section (RCS) scale. The required RCS reference point is obtained from highly accurate solutions of Maxwell's equations for a modeled reference target and scene. Electrical characteristics of this modeled target and scene are carefully selected to match ... |
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| Scheduling Under Uncertainty: An Analysis of an Air Force Application |
29 JAN 2007 |
10 pages |
| Authors:
Adele Howe; L. D. Whitley; COLORADO STATE UNIV FORT COLLINS DEPT OF COMPUTER SCIENCE
|
| We investigated a new scheduling application under uncertainty: the Eglin AFB phased array radar tracks thousands of objects in space. Because of uncertainty associated with an object's location and radar cross-section, as well as the inherent power limits and weather, scheduling must trade-off maximizing the probability of detection against maximizing the total number of objects scheduled for observation; the system must also dynamically reschedule missed observations and incorporate new requests. ... |
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| Numeric Simulations for Sensing Through the Wall Radar |
NOV 2006 |
9 pages |
| Authors:
Traian Dogaru; Calvin Le; ARMY RESEARCH LAB ADELPHI MD SENSORS AND ELECTRON DEVICES DIRECTORATE
|
| This paper presents numeric simulations related to sensing through the wall radar technologies. Our computational approaches include the Finite Difference Time Domain (FDTD) algorithm and the shooting and bouncing ray technique (Xpatch). We analyze the radar signatures of the human body and other objects, in free-space and inside a room. The emphasis is on radar scattering phenomenology, with results presented as Radar Cross Section (RCS) and Synthetic Aperture Radar (SAR) ... |
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| Digital Array Radar for Ballistic Missile Defense and Counter-Stealth Systems Analysis and Parameter Tradeoff Study |
14 SEP 2006 |
304 pages |
| Authors:
Carla Bacchus; David Bedford; Paul Dailey; Stanley Hill; Ian Barford; Jack Chung; Robert Hazle; Mark Mihocka; NAVAL POSTGRADUATE SCHOOL MONTEREY CA DEPT OF SYSTEMS ENGINEERING
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| United States Navy (USN) sources indicate a need for long-range shipboard radar for the Ballistic Missile Defense (BMD) program to augment and expand the USN's current capabilities. The Naval Postgraduate School (NPS) conducted a study on radar architecture research based on a digital Opportunistic Array (OA) integrated into a ship's hull. Our research defined the operational and technical requirements for the system, called the Digital Array Radar for BMD and ... |
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| Radar Cross-Section (RCS) Measurements of a Dismount With Rocket-Propelled Grenade (RPG) Launcher at Ka-Band |
JUL 2006 |
56 pages |
| Authors:
Suzanne R. Stratton; Robert L. Bender; ARMY RESEARCH LAB ABERDEEN PROVING GROUND MD
|
| The U.S. Army Research Laboratory's (ARL's) Radio Frequency and Electronics Division sponsored and conducted a series of measurements to characterize the millimeter wave (MMW) signatures of one Soldier carrying a rocket-propelled grenade (RPG) launcher with grenade at 34 GHz over three depression angles and for three different body postures: prone, kneeling, and standing. The measurements were taken by ARL at its outdoor signature research facility at Aberdeen Proving Ground, MD, ... |
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| Current MBDA R&T Effort on Ram/Scramjet and Detonation Wave Engine |
May-2006 |
25 pages |
| Authors:
Francois Falempin; MBDA FRANCE CHATILLON
|
| Since the fifties, MBDA France, in close cooperation with ONERA, has been leading a sustained effort to develop ramjet technology. This strong involvment led to the development of the Air Sol Moyenne Port?e (ASMP or Medium Range Air-to-Ground) missile which entered service in the French Air Force in 1986 and will be soon replaced by ASMP A. Beyond this development, a lot of advanced studies were performed during the nineties ... |
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| Determining the Resistivity of Resistive Sheets Using Transmission Measurements |
MAR 2006 |
126 pages |
| Authors:
IV Hyde Milo W.; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH DEPT OF ELECTRICAL AND COMPUTER ENGINEERING
|
| In September 2005, radar cross section (RCS) measurements were made of resistive sheets, or R-cards, wrapped around a polystyrene foam cylinder to compare with a newly developed theoretical RCS prediction technique. The resistivities of the R-cards were initially measured with a direct current (DC) four-point probe. When the RCS measurements were compared to the theoretical predictions, it became clear that DC resistivity alone is not sufficient to accurately predict the ... |
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| Nonlinear Suppression of Range-Ambiguous Clutter for Outdoor Radar Measurement Facilities |
MAR 2006 |
60 pages |
| Authors:
Michael C. Baumgartner; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF ENGINEERING AND MANAGEMENT
|
| In the outdoor measurement facility, a certain amount of real estate is owned by the organization, and therefore can be groomed to keep clutter contributions to a minimum. As the transmit signal travels further down range, however, returns from long-range clutter sources are inevitable and can have a significant impact on measurement accuracy. This research effort investigates the effectiveness of employing nonlinear suppression (NLS) to abate long-range ambiguous clutter in ... |
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| Airborne Radar Search for Diesel Submarines |
15 DEC 2005 |
16 pages |
| Authors:
Steven E. Pilnick; Jose Landa; NAVAL POSTGRADUATE SCHOOL MONTEREY CA DEPT OF OPERATIONS RESEARCH
|
| Aircraft search to catch diesel submarines on the sea surface or with masts exposed above the sea surface has been an anti-submarine warfare tactic for more than half a century. However, rather than analysis, operational judgment has been used to guess at good search tactics such as how large an area one aircraft can cover effectively. In this research, a detection rate model is developed to analyze the effectiveness of ... |
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| Electronically Reconfigurable Microwave Lens Antennas |
13 DEC 2005 |
54 pages |
| Authors:
Liang Xue; Vincent Fusco; QUEEN'S UNIV BELFAST (NORTHERN IRELAND)
|
| The purpose of this report is to present the results of further investigations into the operation and design of two-dimensional Luneburg Lenses at 24 GHz, with the possibility for electronic control of their behavior. Various lens design techniques are illustrated; these include a holey dielectric lens (drilled dielectric), and a holey plate lens (etched holes on the upper metal plate). Ray tracing theory is presented which shows the general properties ... |
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| Automatic Low-Visibility Trajectory Optimization for Visually Identifying a Suspected Aircraft |
28 SEP 2005 |
17 pages |
| Authors:
Leonard Wholey; Leena Singh; MASSACHUSETTS INST OF TECH CAMBRIDGE DEPT OF AERONAUTICS AND ASTRONAUTICS
|
| This paper describes two methods used for producing trajectories, which enable an interceptor aircraft to perform a visual identification on a suspected aircraft. A trajectory typically used by fighter pilots is referred to as a beam intercept. The main goal for the maneuver is to put the interceptor in a relative position and heading with respect to the target such that it is in the best configuration to view the ... |
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| Wide-Angle Multistatic Synthetic Aperture Radar: Focused Image Formation and Aliasing Artifact Mitigation |
28 SEP 2005 |
371 pages |
| Authors:
Jonathan E. Luminati; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF ENGINEERING AND MANAGEMENT
|
| Traditional monostatic Synthetic Aperture Radar (SAR) platforms force the user to choose between two image types: larger, low resolution images or smaller, high resolution images. Switching to a Wide-Angle Multistatic Synthetic Aperture Radar (WAM-SAR) approach allows formation of large high-resolution images. Unfortunately, WAM-SAR suffers from two significant implementation problems. First, wavefront curvature effects, non-linear flight paths, and warped ground planes lead to image defocusing with traditional SAR processing methods. A ... |
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| Launching of Electromagnetic Surface Waves on Axial Cylindrical Reactive Surface with Negative Permittivity |
SEP 2005 |
31 pages |
| Authors:
Ivor L. Morrow; CRANFIELD UNIV (UNITED KINGDOM) ROYAL MILITARY COLLEGE OF SCIENCE
|
| This report results from a contract tasking Royal Military College of Science (RMCS), Cranfield University as follows: The Grantee will investigate methods for reducing radar cross section of antennas. Specifically: 1.) Formulation of the antenna and waveguide launcher problem: (i) Define intra- and exterior-field forms on the antenna, (ii) define negative permittivity expressions appropriate to the medium composing the cylindrical radiator, for e.g., plasma or other electronic resonant media (meta-materials), ... |
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| Environmental Assessment for the Proposed F/A-22 Maintenance Facilities, Hill AFB, Utah |
SEP 2005 |
54 pages |
| Authors:
Kay Winn; URS CORPORATION SALT LAKE CITY UT
|
| Under the proposed action, new facilities would be constructed to accommodate the F/A-22 workload of up to 54 aircraft per year. Included would be the construction of a nondestructive inspection (NDI) facility and the relocation of the existing FPS-117 radar tower. Under the no-action alternative, the proposed F/A-22 complex would not be constructed. The no-action would result in insufficient facilities to adequately sustain Hill AFB s F/A-22 mission. Based on ... |
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| Determination of Interrogating Frequencies to Maximize Electromagnetic Backscatter from Objects with Material Coatings |
27 AUG 2005 |
28 pages |
| Authors:
H. T. Banks; K. Ito; J. Toivanen; NORTH CAROLINA STATE UNIV AT RALEIGH CENTER FOR RESEARCH IN SCIENTIFIC COMPUTATION
|
| The electromagnetic backscattering of a crosscut of a cruise missile coated by a thin homogeneous layer made of radar absorbent material is modeled using a finite element method. Based on the radar cross section and a reflection coefficient, optimization problems are formulated for evaders and interrogators leading to optimal material parameters for the coating and optimal monostatic radar operating frequencies, respectively. Optimal coating materials are constructed for several radar frequencies. ... |
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| The Effects of Target Location Uncertainty in Game Theoretic Solutions to Optimal Trajectory Formulations |
17 AUG 2005 |
234 pages |
| Authors:
Daniel M. Morales; MASSACHUSETTS INST OF TECH CAMBRIDGE DEPT OF AERONAUTICS AND ASTRONAUTICS
|
| The integration of a variety of Intelligence, Surveillance, and Reconnaissance (ISR) assets is vital to the acquisition of knowledge critical to battlefield success. Missions performed by a penetrating Unmanned Aerial Vehicle (UAV) are of particular interest. The environment in which UAVs must operate includes Surface-to-Air Missile (SAM) sites with extended ranges, among other threats. SAM location uncertainty, terrain obscuration, and radar/sensor capabilities all contribute to the complexity of the situation. ... |
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| Wavenumber Spectrum of Intermediate-Scale Ocean Surface Waves |
10 AUG 2005 |
5 pages |
| Authors:
Paul A. Hwang; NAVAL RESEARCH LAB STENNIS SPACE CENTER MS OCEANOGRAPHY DIV
|
| This paper presents an analysis of the wavenumber spectra of intermediate-scale waves (wavelengths between 0.02 and 6 meters) under various sea-state conditions. The main result of the analysis is that the dependence of the dimensionless wave spectrum on the dimensionless wind-friction velocity follows a power-law function. The coefficient and exponent of the power-law function vary systematically with the wavenumber. The wavenumber dependence of the coefficient and exponent serves as an ... |
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| Exploration of the Lower Atmosphere with Millimeter-Wave Radar |
25 JUL 2005 |
5 pages |
| Authors:
Mai T. Ngo; George J. Linde; WinJou J. Cheung; NAVAL RESEARCH LAB WASHINGTON DC RADAR DIV
|
| With the high peak power and large antenna gain of the WARLOC W-band (94 GHz) radar, clear-air radar returns from the lower atmosphere, which have no visible underlying scattering mechanism, have been observed. Due to their close resemblance to classical sea spikes from the sea surface scatter, the unknown phenomena are being referred to as air spikes. In this paper, a brief description of the high power WARLOC radar and ... |
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| New Methods for Landslide Identification and Mapping Using SAR Polarimetry Obtained During the PacRim 2000 Mission in Taiwan |
25 JUL 2005 |
5 pages |
| Authors:
Kristina R. Czuchlewski; Jeffrey K. Weissel; Jong-Sen Lee; COLUMBIA UNIV NEW YORK
|
| We reanalyze PacRim 2000 L-band AIRSAR polarimetry collected over the western foothills of central Taiwan a year after the September 20, 1999 ChiChi earthquake, which produced more than 10,000 landslides. The objective is to explore the utility of SAR data, particularly polarimetry, for identifying and mapping natural hazards like landslides that essentially resurface landscapes. An overall goal of this research is to exploit the operational advantages of radars over optical ... |
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| Airborne Radar Search for Diesel Submarines (ARSDS) |
23 JUN 2005 |
35 pages |
| Authors:
Steven E. Pilnick; Jose Landa; NAVAL POSTGRADUATE SCHOOL MONTEREY CA DEPT OF OPERATIONS RESEARCH
|
| Aircraft search to catch diesel submarines on the sea surface or with masts exposed above the sea surface has been an anti-submarine warfare tactic for more than half a century. However, rather than analysis, operational judgment has been used to guess at good search tactics such as how large an area can one aircraft cover effectively. In this research, a detection rate model is developed to analyze the effectiveness of ... |
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| Electronic Attack and Sensor Fusion Techniques for Boost-phase Defense Against Multiple Ballistic Threat Missiles |
JUN 2005 |
|
| Authors:
Kursad Yildiz; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
|
| The first objective of this thesis is to investigate the effect of several forms of electronic attack (EA) on the radio frequency (RF) sensors used within a boost-phase ballistic missile intercept system. The EA types examined include noise jamming, chaff, radar cross section (RCS) reduction, and expendable decoys. Effects of the EA methods are evaluated by examining the track position error at the sensor fusion output. Sensor fusion architectures investigated ... |
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| RCS Measurements and High-Range Resolution Profiles of Three RPGs at Ka-Band |
JUN 2005 |
18 pages |
| Authors:
Thomas J. Pizzillo; ARMY RESEARCH LAB ADELPHI MD
|
| Static radar cross section and high range resolution profile measurements of 3 rocket-propelled grenades (RPG) at Ka- band are reported. Measurements are from 32.4 to 35.6 GHz with vertically polarized transmit and receive stepped frequency waveforms providing 4.7 cm resolution in range for each of the following: Yugoslavian M57 grenade, Chinese Type 69 grenade, and a Romanian PG7M grenade. Measurements include azimuth aspect angles between -3 deg and +3 deg ... |
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| Fabrication of Organic Radar Absorbing Materials: A Report on the TIF Project |
MAY 2005 |
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| Authors:
Paul Saville; Trisha Huber; Darren Makeiff; DEFENCE RESEARCH AND DEVELOPMENT ATLANTIC DARTMOUTH (CANADA)
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| The fabrication of microwave absorbing materials requires the ability to make materials with well-controlled properties such as shape, thickness, permittivity and permeability. The ability to measure the permittivity and permeability is an essential requirement for designing an optimised absorber. And good optimisations codes are required in order to achieve the best possible absorber designs. In this report, the results from a Technology Investment Funded project on the fabrication of organic ... |
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| RF Signature Modeling and Analysis - Lessons Learned |
MAY 2005 |
29 pages |
| Authors:
W. Coburn; C. Le; C. Kenyon; E. Burke; ARMY RESEARCH LAB ADELPHI MD RF ELECTRONICS DIV
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| Discusses lessons learned in modelling radar signatures in the Ka, W, and X bands. |
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| Clutter Characterization and Propagation Measurements During Adverse Weather Conditions |
14 APR 2005 |
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| Authors:
J. A. Bruder; M. C. Brinkmann; G. R. Whitley; T. L. Lane; Paul Granger; GEORGIA TECH RESEARCH INST ATLANTA
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| The evaluation of sensor performance under adverse weather conditions is critical for the determination of usability during all weather conditions. The Precisions Armaments Laboratory (PAL) located at the US Army Picatinny Arsenal, New Jersey, USA development will enable automated measurement of propagation effects and clutter characterization under adverse conditions. |
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