Open Access. Powered by Scholars. Published by Universities.®
- Keyword
-
- Electrical Engineering (48)
- Chemical Engineering (16)
- Electric measurements (10)
- Epitaxy (8)
- Doping (7)
-
- Electrical resistivity (7)
- Heterojunctions (7)
- International Journal of Engineering Research (IJER) (7)
- Thin films (7)
- Field effect transistors (6)
- Activation energies (5)
- III-V semiconductors (5)
- Ladar (5)
- Leakage currents (5)
- MODFETs (5)
- Crystal defects (4)
- Lung cancer (4)
- Materials properties (4)
- Mechanical Engineering (4)
- Nickel (4)
- Phonons (4)
- Semiconductor surfaces (4)
- Thin film (4)
- Aliasing (3)
- Antimony compounds (3)
- Building design (3)
- Campus Sustainability (3)
- Coercive force (3)
- Contact potential (3)
- Dielectric thin films (3)
- Publication
-
- Russell C. Hardie (48)
- Bradley D. Duncan (36)
- Guru Subramanyam (33)
- Krishna C. Mandal (31)
- Mikhail Vasiliev (19)
-
- Grigory Simin (17)
- Jason R. Hattrick-Simpers (16)
- Innovative Research Publications IRP India (9)
- Faculty of Engineering University of Malaya (6)
- Mikhail Vorontsov (6)
- Nathan Ida (6)
- Marco Duarte (5)
- Almoataz Youssef Abdelaziz (4)
- Richard A. Malthaner (4)
- Ludmilla D Pavlova (3)
- Radhey Shyam Meena (3)
- U. Guler (3)
- Xingjian "Chris" Xue (3)
- Amean S Al_Safi (2)
- Carmine Vittoria (2)
- Chin-Leong Lim (2)
- Dr. Adel A. Elbaset (2)
- Hamid Bahrami (2)
- Hanz Richter (2)
- Igor Tsukerman (2)
- Kang Peng (2)
- Ronald Brown (2)
- Andrew Sarangan (1)
- Bilge Nazli Altay (1)
- David C. Brown (1)
- File Type
Articles 1 - 30 of 292
Full-Text Articles in Engineering
Constrained Biogeography-Based Optimization For Invariant Set Computation,, Arpit Shah, Daniel Simon, Hanz Richter
Constrained Biogeography-Based Optimization For Invariant Set Computation,, Arpit Shah, Daniel Simon, Hanz Richter
Hanz Richter
We discuss the application of biogeography-based optimization (BBO) to invariant set approximation. BBO is a recently developed evolutionary algorithm (EA) that is motivated by biogeography, which is the study and science of the geographical migration of biological species. Invariant sets are sets in the state space of a dynamic system such that if the state begins in the set, then it remains in the set for all time. Invariant sets have applications in many constrained control problems, and their computation amounts to a constrained optimization problem. We therefore frame the invariant set computation problem as a constrained optimization problem, and …
Characterization Of Ten Channel Electro-Optic Phase Modulator And Amplifier In Algaas/Gaas, David Brown
Characterization Of Ten Channel Electro-Optic Phase Modulator And Amplifier In Algaas/Gaas, David Brown
David C. Brown
No abstract provided.
Dynamic Modeling, Parameter Estimation And Control Of A Leg Prosthesis Test Robot, Hanz Richter, Daniel Simon, William Smith, Sergey Samorezov
Dynamic Modeling, Parameter Estimation And Control Of A Leg Prosthesis Test Robot, Hanz Richter, Daniel Simon, William Smith, Sergey Samorezov
Hanz Richter
Robotic testing can facilitate the development of new concepts, designs and control systems for prosthetic limbs. Human subject test clearances, safety and the lack of repeatability associated with human trials can be reduced or eliminated with automated testing, and test modalities are possible which are dangerous or inconvenient to attempt with patients. This paper describes the development, modeling, parameter estimation and control of a robot capable of reproducing two degree-of-freedom hip motion in the sagittal plane. Hip vertical displacement and thigh angle motion profiles are applied to a transfemoral prosthesis attached to the robot. A treadmill is used as walking …
Data And Network Optimization Effect On Web Performance, Steven Rosenberg, Surbhi Dangi, Isuru Warnakulasooriya
Data And Network Optimization Effect On Web Performance, Steven Rosenberg, Surbhi Dangi, Isuru Warnakulasooriya
Surbhi Dangi
In this study, we measure the effects of two software approaches to improving data and network performance: 1. Content optimization and compression; and 2. Optimizing network protocols. We achieve content optimization and compression by means of BoostEdge by ActivNetworks and employ the SPDY network protocol by Google to lower the round trip time for HTTP transactions. Since the data and transport layers are separate, we conclude our investigation by studying the combined effect of these two techniques on web performance. Using document mean load time as the measure, we found that with and without packet loss, both BoostEdge and SPDY …
A Platinum Nanowire Network As A Highly Effective Current Collector For Intermediate Temperature Solid Oxide Fuel Cells, Hanping Ding, Xingjian Xue
A Platinum Nanowire Network As A Highly Effective Current Collector For Intermediate Temperature Solid Oxide Fuel Cells, Hanping Ding, Xingjian Xue
Xingjian "Chris" Xue
We report the fabrication and evaluation of a platinum nanowire network as a highly efficient current collector for solid oxide fuel cells (SOFCs). The ink of carbon-black supported platinum nanoparticles was sprayed onto the cathode. After firing, the carbon black was oxidized and disappeared as carbon dioxide gas while the platinum nanoparticles connect with one another, forming a tree-branch-like nanowire network. The diameters of the nanowires range from 100 nm to 400 nm. Compared to a conventional platinum paste current collector, the polarization resistance of the PrBaCo2O5+δ (PBCO) cathode with a nanowire current collector was reduced …
A Platinum Nanowire Network As A Highly Effective Current Collector For Intermediate Temperature Solid Oxide Fuel Cells, Hanping Ding, Xingjian Xue
A Platinum Nanowire Network As A Highly Effective Current Collector For Intermediate Temperature Solid Oxide Fuel Cells, Hanping Ding, Xingjian Xue
Xingjian "Chris" Xue
We report the fabrication and evaluation of a platinum nanowire network as a highly efficient current collector for solid oxide fuel cells (SOFCs). The ink of carbon-black supported platinum nanoparticles was sprayed onto the cathode. After firing, the carbon black was oxidized and disappeared as carbon dioxide gas while the platinum nanoparticles connect with one another, forming a tree-branch-like nanowire network. The diameters of the nanowires range from 100 nm to 400 nm. Compared to a conventional platinum paste current collector, the polarization resistance of the PrBaCo2O5+δ (PBCO) cathode with a nanowire current collector was reduced by 44% at 650 …
Ba-Hexaferrite Films For Next Generation Microwave Devices, Vincent Girard Harris (1962-), Zhaohui Chen, Yajie Chen, Soack Dae Yoon, Tomokuza Sakai, Anton Geiler, Aria Fan Yang, Yongxue He, Katherine S. Ziemer, Nian X. Sun, C. Vittoria
Ba-Hexaferrite Films For Next Generation Microwave Devices, Vincent Girard Harris (1962-), Zhaohui Chen, Yajie Chen, Soack Dae Yoon, Tomokuza Sakai, Anton Geiler, Aria Fan Yang, Yongxue He, Katherine S. Ziemer, Nian X. Sun, C. Vittoria
Carmine Vittoria
Next generation magnetic microwave devices require ferrite films to be thick (>300 μm), self-biased (high remanent magnetization), and low loss in the microwave and millimeter wave bands. Here we examine recent advances in the processing of thick Ba-hexaferrite (M-type) films using pulsed laser deposition (PLD), liquid-phase epitaxy, and screen printing. These techniques are compared and contrasted as to their suitability for microwave materials processing and industrial production. Recent advances include the PLD growth of BaM on wide-band-gap semiconductor substrates and the development of thick, self-biased, low-loss BaM films by screen printing.
Ba-Hexaferrite Films For Next Generation Microwave Devices, Vincent Girard Harris (1962-), Zhaohui Chen, Yajie Chen, Soack Dae Yoon, Tomokuza Sakai, Anton Geiler, Aria Fan Yang, Yongxue He, Katherine S. Ziemer, Nian X. Sun, C. Vittoria
Ba-Hexaferrite Films For Next Generation Microwave Devices, Vincent Girard Harris (1962-), Zhaohui Chen, Yajie Chen, Soack Dae Yoon, Tomokuza Sakai, Anton Geiler, Aria Fan Yang, Yongxue He, Katherine S. Ziemer, Nian X. Sun, C. Vittoria
Carmine Vittoria
Next generation magnetic microwave devices require ferrite films to be thick (>300 μm), self-biased (high remanent magnetization), and low loss in the microwave and millimeter wave bands. Here we examine recent advances in the processing of thick Ba-hexaferrite (M-type) films using pulsed laser deposition (PLD), liquid-phase epitaxy, and screen printing. These techniques are compared and contrasted as to their suitability for microwave materials processing and industrial production. Recent advances include the PLD growth of BaM on wide-band-gap semiconductor substrates and the development of thick, self-biased, low-loss BaM films by screen printing.
Vanadium Oxide Thin-Film Variable Resistor-Based Rf Switches, Kuanchang Pan, Weisong Wang, Eunsung Shin, Kelvin Freeman, Guru Subramanyam
Vanadium Oxide Thin-Film Variable Resistor-Based Rf Switches, Kuanchang Pan, Weisong Wang, Eunsung Shin, Kelvin Freeman, Guru Subramanyam
Guru Subramanyam
Vanadium dioxide (VO2) is a unique phase change material (PCM) that possesses a metal-to-insulator transition property. Pristine VO2 has a negative temperature coefficient of resistance, and it undergoes an insulator-to-metal phase change at a transition temperature of 68°C. Such a property makes the VO2 thin-film-based variable resistor (varistor) a good candidate in reconfigurable electronics to be integrated with different RF devices such as inductors, varactors, and antennas. Series single-pole single-throw (SPST) switches with integrated VO2 thin films were designed, fabricated, and tested. The overall size of the device is 380 μm × 600 μm. The SPST switches were fabricated on …
A High Performance Ceramic-Polymer Separator For Lithium Batteries, Jitendra Kumar, Padmakar Kichambare, Amarendra K. Rai, Rabi Bhattacharya, Stanley J. Rodrigues, Guru Subramanyam
A High Performance Ceramic-Polymer Separator For Lithium Batteries, Jitendra Kumar, Padmakar Kichambare, Amarendra K. Rai, Rabi Bhattacharya, Stanley J. Rodrigues, Guru Subramanyam
Guru Subramanyam
A three-layered (ceramic-polymer-ceramic) hybrid separator was prepared by coating ceramic electrolyte [lithium aluminum germanium phosphate (LAGP)] over both sides of polyethylene (PE) polymer membrane using electron beam physical vapor deposition (EB-PVD) technique. Ionic conductivities of membranes were evaluated after soaking PE and LAGP/PE/LAGP membranes in a 1 Molar (1M) lithium hexafluroarsenate (LiAsF6) electrolyte in ethylene carbonate (EC), dimethyl carbonate (DMC) and ethylmethyl carbonate (EMC) in volume ratio (1:1:1). Scanning electron microscopy (SEM) and X-ray diffraction (XRD) techniques were employed to evaluate morphology and structure of the separators before and after cycling performance tests to better understand structure-property correlation. As compared …
Industry-University Collaboration: A University Of Dayton Model, Guru Subramanyam
Industry-University Collaboration: A University Of Dayton Model, Guru Subramanyam
Guru Subramanyam
This paper introduces industry-university collaboration activities currently in place at the University of Dayton's School of Engineering. These collaborations are important to prepare industry-ready graduates who excel in technical, entrepreneurial, and leadership skills. One of the key curricular components is the industry-sponsored multidisciplinary projects. Industry involvement in advisory committee, strategic research partnerships, and other forms are discussed.
Pv-Wind System With Fuel Cell & Electrolyzer, Deepa Sharma,, 2radhey Shyam Meena, Dr. D. K. .Birla
Pv-Wind System With Fuel Cell & Electrolyzer, Deepa Sharma,, 2radhey Shyam Meena, Dr. D. K. .Birla
Innovative Research Publications IRP India
In this paper, a detailed modeling and simulation of solar cell/ wind turbine/ fuel cell hybrid power system is developed using a novel topology to complement each other and to alleviate the effects of environmental variations. Comparing with the other sources , the renewable energy is inexhaustible and has non-pollution characteristics. The solar energy, wind power, hydraulic power and tidal energy are natural resources of the interest to generate electrical power. As the wind turbine output power varies with the wind speed and the solar cell output power varies with both the ambient temperature and radiation, a fuel cell with …
Contouring Control For A Cnc Milling Machine Driven By Direct Thrust Controlled Linear Induction Motors, Khaled N. Faris, Hala S. Khalil, Khaled S. Sakkoury
Contouring Control For A Cnc Milling Machine Driven By Direct Thrust Controlled Linear Induction Motors, Khaled N. Faris, Hala S. Khalil, Khaled S. Sakkoury
Innovative Research Publications IRP India
According to various advantages of linear induction motor (LIM), such as high starting thrust force, high speed operation and reduction of mechanical losses, more applications have utilized this type of motors. Direct Thrust Control (DTC) technique is considered as one of the most efficient techniques that can be used for LIM. DTC is preferable to give a fast and good dynamic thrust response. So, to improve the accuracy and robustness of contouring control for CNC machine tools, linear induction motors with a direct thrust control technique are introduced for driving these machines. An industry standard motion control system is applied …
A Nonasymptotic Homogenization Theory Of Electromagnetic Metamaterials, Igor Tsukerman, Vadim Markel
A Nonasymptotic Homogenization Theory Of Electromagnetic Metamaterials, Igor Tsukerman, Vadim Markel
Igor Tsukerman
We propose a new homogenization methodology for periodic electromagnetic structures (photonic crystals and metamaterials). The physical essence of this methodology is in seeking effective material parameters that provide, in some sense, the best approximation of Bloch impedances as well as dispersion relations over an ensemble of physical modes in the structure. Mathematically, the homogenization problem is solved by approximating the fields on the fine and coarse scales with the respective eigenmodes that satisfy Maxwell's equations and boundary conditions as accurately as possible.
Trefftz Absorbing Boundary Conditions In Analytical, Discontinuous Galerkin And Finite Difference Form, Fritz Kretzschmar, Farzad Ahmadi, Nabil Nowak, Sascha Schnepp, Igor Tsukerman, Herbert Egger, Thomas Weiland
Trefftz Absorbing Boundary Conditions In Analytical, Discontinuous Galerkin And Finite Difference Form, Fritz Kretzschmar, Farzad Ahmadi, Nabil Nowak, Sascha Schnepp, Igor Tsukerman, Herbert Egger, Thomas Weiland
Igor Tsukerman
We explore a novel avenue for generating absorbing boundary conditions for wave problems. The key part of our approach is Trefftz approximations of the solution, i.e. approximations by functions satisfying locally the underlying wave equation. Trefftz functions include outgoing waves only (and possibly evanescent waves), but no incoming waves. We show how this idea can be applied in three different contexts: analytical, Discontinuous Galerkin, and finite difference.
Investigation Of Real-Time Optical Scanning Holography, Bradley D. Duncan
Investigation Of Real-Time Optical Scanning Holography, Bradley D. Duncan
Bradley D. Duncan
Real-time holographic recording using an optical heterodyne scanning technique was proposed by Poon in 1985. The first part of this dissertation provides a detailed theoretical treatment of the technique, based on a Gaussian beam analysis. Topics to be addressed include the derivations of the optical transfer function (OTF) and impulse response of the scanning holographic recording system, reconstructed image resolution and magnification, methods of carrier frequency hologram generation and experimental verification of the recording technique based on careful measurements of a hologram corresponding to a simple transmissive slit. Furthermore, computer simulations are presented pertaining to the incoherent nature of the …
Imaging Diffractometer With Holographic Encoding Enhancements For Laser Sensing And Characterization, Joesph Binford, Bradley Duncan, Jack Parker, Elizabeth Beecher, Mark Delong
Imaging Diffractometer With Holographic Encoding Enhancements For Laser Sensing And Characterization, Joesph Binford, Bradley Duncan, Jack Parker, Elizabeth Beecher, Mark Delong
Bradley D. Duncan
What is believed to be a novel holographic optical encoding scheme has been developed to enhance the performance of laser sensors designed for the measurement of wavelength and angular trajectory. A prototype holographic imaging diffractometer has been created to reconstruct holographic cueing patterns superimposed in the focal plane of wide-angle scene imagery. Based on experimental pattern metric measurements at the focal plane, a theoretical model is used to compute the laser source wavelength and its apparent propagation direction within the sensor's field of view. The benefits of incorporating holographic enhancements within an imager-based sensor architecture are discussed.
Review: 'Optical Fiber Communications' (2nd Edition), By Gerd Keiser, Bradley D. Duncan
Review: 'Optical Fiber Communications' (2nd Edition), By Gerd Keiser, Bradley D. Duncan
Bradley D. Duncan
If first impressions are worth anything (and they usually are), I would have to admit that my first impression of the second edition of Gerd Keiser's now popular text Optical Fiber Communications was quite good. My compliments are hereby extended to the publisher for choosing a rather handsome cover and dust jacket. It stands in strong contrast to the text's first edition, which still ranks as probably the ugliest book I own, with color choices ranging from dull cream and "baby" blue to pale pink! I am now happy to say that this older version has been discretely·retired to the …
Optical Sparse Aperture Imaging, Nicholas Miller, Matthew Dierking, Bradley Duncan
Optical Sparse Aperture Imaging, Nicholas Miller, Matthew Dierking, Bradley Duncan
Bradley D. Duncan
The resolution of a conventional diffraction-limited imaging system is proportional to its pupil diameter. A primary goal of sparse aperture imaging is to enhance resolution while minimizing the total light collection area; the latter being desirable, in part, because of the cost of large, monolithic apertures. Performance metrics are defined and used to evaluate several sparse aperture arrays constructed from multiple, identical, circular subapertures. Subaperture piston and∕or tilt effects on image quality are also considered. We selected arrays with compact nonredundant autocorrelations first described by Golay. We vary both the number of subapertures and their relative spacings to arrive at …
Monte Carlo Simulation Of Multiple Photon Scattering In Sugar Maple Tree Canopies, Michael Greiner, Bradley Duncan, Matthew Dierking
Monte Carlo Simulation Of Multiple Photon Scattering In Sugar Maple Tree Canopies, Michael Greiner, Bradley Duncan, Matthew Dierking
Bradley D. Duncan
Detecting objects hidden beneath forest canopies is a difficult task for optical remote sensing systems. Rather than relying upon the existence of gaps between leaves, as other researchers have done, our ultimate goal is to use light scattered by leaves to image through dense foliage. Herein we describe the development of a Monte Carlo model for simulating the scattering of light as it propagates through the leaves of an extended tree canopy. We measured several parameters, including the gap fraction and maximum leaf-area density, of a nearby sugar maple tree grove and applied them to our model. We report the …
Improving Mid-Frequency Contrast In Sparse Aperture Optical Imaging Systems Based Upon The Golay-9 Array, Andrew Stokes, Bradley Duncan, Matthew Dierking
Improving Mid-Frequency Contrast In Sparse Aperture Optical Imaging Systems Based Upon The Golay-9 Array, Andrew Stokes, Bradley Duncan, Matthew Dierking
Bradley D. Duncan
Sparse aperture imaging systems are capable of producing high resolution images while maintaining an overall light collection area that is small compared to a fully filled aperture yielding the same resolution. This is advantageous for applications where size, volume, weight and/or cost are important considerations. However, conventional sparse aperture systems pay the penalty of reduced contrast at midband spatial frequencies. This paper will focus on increasing the midband contrast of sparse aperture imaging systems based on the Golay-9 array. This is one of a family of two-dimensional arrays we have previously examined due to their compact, non-redundant autocorrelations. The modulation …
Periodic, Pseudo-Noise Waveforms For Multi-Function Coherent Ladar, Matthew Dierking, Bradley Duncan
Periodic, Pseudo-Noise Waveforms For Multi-Function Coherent Ladar, Matthew Dierking, Bradley Duncan
Bradley D. Duncan
We report the use of periodic, pseudonoise waveforms in a multifunction coherent ladar system. We exploit the Doppler sensitivity of these waveforms, as well as agile processing, to enable diverse ladar functions, including high range resolution imaging, macro-Doppler imaging, synthetic aperture ladar, and range-resolved micro-Doppler imaging. We present analytic expressions and simulations demonstrating the utility of pseudonoise waveforms for each of the ladar modes. We also discuss a laboratory pseudonoise ladar system that was developed to demonstrate range compression and range-resolved micro-Doppler imaging, as well as the phase recovery common to each of the coherent modes.
Holographic Aperture Ladar, Bradley Duncan, Matthew Dierking
Holographic Aperture Ladar, Bradley Duncan, Matthew Dierking
Bradley D. Duncan
Holographic aperture ladar is a variant of synthetic aperture ladar that seeks to increase cross-range scene resolution by synthesizing a large effective aperture through the motion of a smaller receiver and through the subsequent proper phasing and correlation of the detected signals in postprocessing. Unlike in conventional synthetic aperture ladar, however, holographic aperture ladar makes use of a two- dimensional translating sensor array, not simply a translating point detector. Also unlike in conventional synthetic aperture ladar, holographic aperture images will be formed in the two orthogonal cross-range dimensions parallel and perpendicular to the sensor platform’s direction of motion. The central …
Experimental Demonstration Of A Stripmap Holographic Aperture Ladar System, Jason Stafford, Bradley Duncan, Matthew Dierking
Experimental Demonstration Of A Stripmap Holographic Aperture Ladar System, Jason Stafford, Bradley Duncan, Matthew Dierking
Bradley D. Duncan
By synthesizing large effective apertures through the translation of a smaller imaging sensor and the subsequent proper phasing and correlation of detected signals in postprocessing, holographic aperture ladar (HAL) systems seek to increase the resolution of remotely imaged targets. The stripmap HAL process was demonstrated in the laboratory, for the first time to our knowledge. Our results show that the stripmap HAL transformation can precisely account for off-axis transmitter induced phase migrations. This in turn allows multiple pupil plane field segments, sequentially collected across a synthetic aperture, to be coherently mosaiced together. As a direct consequence, we have been able …
Review: 'Theory Of Dielectric Optical Waveguides,' 2nd Edition, By Dietrich Marcuse, Bradley D. Duncan
Review: 'Theory Of Dielectric Optical Waveguides,' 2nd Edition, By Dietrich Marcuse, Bradley D. Duncan
Bradley D. Duncan
I suppose I ought to say up front that while preparing this review I often found myself feeling very much like a student evaluating his teacher. After all, it was, in part, the first edition of Dietrich Marcuse's Theory of Dielectric Optical Waveguides (among a handful of other similar texts) from which I first studied the principles of optical waveguide theory under the demanding, yet patient and graceful guidance of Dr. Ahmad Safaai-Jazi. Thus with the utmost respect for a teacher whom I have never met, I shall try to faithfully share my thoughts and feelings regarding the second edition …
Modal Interference Techniques For Strain Detection In Few-Mode Optical Fibers, Bradley D. Duncan
Modal Interference Techniques For Strain Detection In Few-Mode Optical Fibers, Bradley D. Duncan
Bradley D. Duncan
Interference between the modes of an optical fiber results in specific intensity patterns which can be modulated as a function of disturbances in the optical fiber system. These modulation effects are a direct result of the difference in propagation constants of the constituent modes. In this presentation it is shown how the modulated intensity patterns created by the interference of specific mode groups in few-mode optical fibers (V < 5.0) can be used to detect strain. A detailed discussion of the modal phenomena responsible for the observed strain induced pattern modulation is given and it is shown that strain detection sensitivities …
Effects Of Spatial Modes On Ladar Vibration Signature Estimation, Douglas Jameson, Matthew Dierking, Bradley Duncan
Effects Of Spatial Modes On Ladar Vibration Signature Estimation, Douglas Jameson, Matthew Dierking, Bradley Duncan
Bradley D. Duncan
Ladar-based vibrometry has been shown to be a powerful technique in enabling the plant identification of machines. Rather than sensing the geometric shape of a target laser vibrometers sense motions of the target induced by moving parts within the system. Since the target need not be spatially resolved, vibration can be sensed reliably and provide positive identification at ranges beyond the imaging limits of the aperture. However, as the range of observation increases, the diffraction-limited beam size on the target increases as well, and may encompass multiple vibrational modes on the target's surface. As a result, vibration estimates formed from …
Bidirectional Scattering Distribution Functions Of Maple And Cottonwood Leaves, Michael Greiner, Bradley Duncan, Matthew Dierking
Bidirectional Scattering Distribution Functions Of Maple And Cottonwood Leaves, Michael Greiner, Bradley Duncan, Matthew Dierking
Bradley D. Duncan
We present our investigations into the optical scattering properties of both sugar maple (Acer saccarum) and eastern cottonwood (Populus deltoides) leaves in the near-IR wavelength regime. The bidirectional scattering distribution function (BSDF) describes the fractions of light reflected by and transmitted through a leaf for a given set of illumination and observation angles. Experiments were performed to measure the BSDF of each species at a discrete set of illumination and observation angles. We then modeled the BSDFs in such a way that other researchers may interpolate their values for scattering in any direction under illumination at any angle.
Demonstrated Resolution Enhancement Capability Of A Stripmap Holographic Aperture Ladar System, Samuel Venable, Bradley Duncan, Matthew Dierking, David Rabb
Demonstrated Resolution Enhancement Capability Of A Stripmap Holographic Aperture Ladar System, Samuel Venable, Bradley Duncan, Matthew Dierking, David Rabb
Bradley D. Duncan
Holographic aperture ladar (HAL) is a variant of synthetic aperture ladar (SAL). The two processes are related in that they both seek to increase cross-range (i.e., the direction of the receiver translation) image resolution through the synthesis of a large effective aperture. This is in turn achieved via the translation of a receiver aperture and the subsequent coherent phasing and correlation of multiple received signals. However, while SAL imaging incorporates a translating point detector, HAL takes advantage of a two-dimensional translating sensor array. For the research presented in this article, a side-looking stripmap HAL geometry was used to sequentially image …
Saturated Semiconductor Optical Amplifier Phase Modulation For Long Range Laser Radar Applications, Jennifer Carns, Bradley Duncan, Matthew Dierking
Saturated Semiconductor Optical Amplifier Phase Modulation For Long Range Laser Radar Applications, Jennifer Carns, Bradley Duncan, Matthew Dierking
Bradley D. Duncan
We investigate the use of a semiconductor optical amplifier operated in the saturation regime as a phase modulator for long range laser radar applications. The nature of the phase and amplitude modulation resulting from a high peak power Gaussian pulse, and the impact this has on the ideal pulse response of a laser radar system, is explored. We also present results of a proof-of-concept laboratory demonstration using phase-modulated pulses to interrogate a stationary target.