| The Temperature-Dependent Nature of Coronal Dimmings |
Jul 2010 |
14 pages |
| Authors:
Eva Robbrecht; Yi-Ming Wang; NAVAL RESEARCH LAB WASHINGTON DC
|
 | The opening-up of the magnetic field during solar eruptive events is often accompanied by a dimming of the local coronal emission. From observations of filament eruptions recorded with the Extreme-Ultraviolet Imager on STEREO during 2008-2009, it is evident that these dimmings are much more pronounced in 19.5 nm than in the lower-temperature line 17.1 nm, as viewed either on the disk or above the limb. We conclude that most of ... |
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| Diamond Nanowire for UV Detection |
28 Feb 2010 |
20 pages |
| Authors:
Jimmy Xu; Jin H Kim; Chih-Hsun Hsu; Hongsik Park; Steven Palefsky; BROWN UNIV PROVIDENCE RI DIV OF ENGINEERING
|
| A number of important discoveries about diamond nanowires were made. First is the proof that this novel morphology of carbon can exist, and can be fabricated in a CVD process at atmospheric pressure. Raman spectroscopy, TEM, SEM, electron diffraction, and photoluminescence spectroscopy were used to characterize the NWs. These measurements showed that the nanowires are formed of diamond with high crystallinity and high uniformity, encased in a graphitic shell. DNWs ... |
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| CW UV Radiation Through Second-Harmonic Generation of Blue Diode-Laser Output |
19 Jan 2010 |
19 pages |
| Authors:
Wolfgang Rudolph; NEW MEXICO UNIV ALBUQUERQUE DEPT OF PHYSICS AND ASTRONOMY
|
| Cavity enhanced second-harmonic generation of a cw blue (440 nm) diode laser output is achieved using a nonlinear crystal BBO in an external, high finesse ring cavity. Simulations show that under ideal beam conditions the generation of 30 mW UV power is possible with 250 mW of incident power when design parameters are optimized. Output is observed at 220 nm at power levels that currently do not exceed a few ... |
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| Zinc Selenide-Based Schottky Barrier Detectors for Ultraviolet-A and Ultraviolet-B Detection |
Jan 2010 |
6 pages |
| Authors:
V Naval; C Smith; V Ryzhikov; S Naydenov; F Alves; G Karunasiri; NAVAL POSTGRADUATE SCHOOL MONTEREY CA DEPT OF PHYSICS
|
| Wide-bandgap semiconductors such as zinc selenide (ZnSe) have become popular for ultraviolet (UV) photodetectors due to their broad UV spectral response. Schottky barrier detectors made of ZnSe in particular have been shown to have both low dark current and high responsivity. This paper presents the results of electrical and optical characterization of UV sensors based on ZnSe/Ni Schottky diodes fabricated using single-crystal ZnSe substrate with integrated UV-A (320?400 nm) and ... |
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| Improving the Accuracy of the SeaUV Algorithms in Dark Marine Waters |
2010 |
8 pages |
| Authors:
William L. Miller; GEORGIA UNIV ATHENS DEPT OF MARINE SCIENCES
|
| Our long-term objective is to develop a robust set of algorithms for the global ocean to provide accurate surface UV attenuation and CDOM retrieval from remotely sensed ocean color for use in optical, photochemical, and photobiological investigation. |
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| Characterization of Zinc Selenide-Based Ultraviolet Detectors |
Dec 2009 |
56 pages |
| Authors:
Naval; Victoriano C Jr; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
|
| Wide bandgap semiconductors such as Zinc Selenide (ZnSe) have become popular for ultraviolet (UV) photodetectors. ZnSe has a higher photosensitivity compared to silicon-based detectors due to its larger bandgap. Its capability of turning optical power into valuable electrical signals makes it suitable for measurement and recording of UV exposure for military personnel. The prospect of ZnSe's unique medical and military applications has been the driving force of this study. This ... |
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| Exploring Techniques for Improving Retrievals of Bio-optical Properties of Coastal Waters |
Jan 2009 |
14 pages |
| Authors:
Samir Ahmed; Fred Moshary; Barry Gross; Alexander Gilerson; CITY COLL OF THE CITY UNIV OF NEW YORK DEPT OF ELECTRICAL ENGINEERING
|
| Long-term goals: Development of algorithms for improved retrievals of inherent water optical properties (IOP) from satellite imagery of coastal waters with current and future sensors utilizing: 1) NIR and UV channels, 2) water polarization characteristics and 3) advanced atmospheric correction schemes. |
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| Sensor Performance Optimization Tool (SPOT) |
Jun 2008 |
47 pages |
| Authors:
James S Richardson; SYSTEMS PLANNING AND ANALYSIS INC ALEXANDRIA VA
|
| BACKGROUND: USCG is in the process of acquiring improved infrared (IR) sensor systems for installation on standard rotary-wing platforms. Historically, IR sensor systems have not been used for primary detection work. Question remains, How can these high-tech sensors be best employed to assist in obtaining initial detections on hard-to-find targets? |
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| Analysis of Physical and Numerical Factors for Prediction of UV Radiation from High Altitude Two-Phase Plumes |
30-May-2008 |
18 pages |
| Authors:
Natalia E Gimelshein; Robert B Lyons; James G Reuster; Sergey F Gimelshein; ENGINEERING RESEARCH AND CONSULTING INC (ERC INC) EDWARDS AFB CA
|
| Numerical study of a 5,900 lb solid propellant thruster plume at an altitude of 118 km is performed using a combined multi-step continuum/kinetic approach. The Navier-Stokes equations are solved for the flow inside the nozzle and the first several meters into the plume. The DSMC method is used to simulate the remaining plume and the plume-free stream interaction. A Monte Carlo based radiation code is applied in an overlay mode ... |
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| Exploring Techniques for Improving Retrievals of Bio-optical Properties of Coastal Waters |
Jan 2008 |
13 pages |
| Authors:
Samir Ahmed; Fred Moshary; Barry Gross; Alexander Gilerson; CITY COLL NEW YORK DEPT OF ELECTRICAL ENGINEERING
|
| Development of algorithms for improved retrievals of inherent water optical properties (IOP) from satellite imagery of coastal waters with current and future sensors utilizing: 1) NIR and UV channels, 2) water polarization characteristics and 3) advanced atmospheric correction schemes. Analysis of methodologies for the enhancement of algorithms for IOP retrieval from reflectance spectra based on additional measurements in NIR and UV through: a) the use of reflectance characteristics obtained from ... |
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| Improving the Accuracy of the SeaUV Algorithms in Dark Marine Waters |
Jan 2008 |
7 pages |
| Authors:
William L Miller; GEORGIA UNIV ATHENS DEPT OF MARINE SCIENCES
|
| Our long-term objective is to develop a robust set of algorithms for the global ocean to provide accurate surface UV attenuation and CDOM retrieval from remotely sensed ocean color for use in optical, photochemical, and photobiological investigation. The central objective of this project is to generate new, high quality optical data sets for a variety of darker coastal systems to be used in evaluating SeaUV algorithms and retraining them for ... |
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| Synthetic Aperture Ladar for Tactical Imaging (SALTI) (Briefing Charts) |
Jul 2007 |
16 pages |
| Authors:
Jennifer Ricklin; Bryce Schumm; Matt Dierking; Phil Tomlinson; Scott Fuhrer; AIR FORCE RESEARCH LAB WRIGHT-PATTERSON AFB OH SENSORS DIRECTORATE
|
| Flight demonstrations have proven the feasibility of synthetic aperture LADAR (SAL) imaging and have produced outstanding imagery of vehicles and engineering test targets. These tests were conducted under the Synthetic Aperture LADAR for Tactical Imaging (SALTI) program. SALTI is a Defense Advanced Research Project Agency program executed with the Air Force Research Laboratory, Sensors Directorate which has demonstrated practical SAL architectures. The atmospheric and target phenomenologies were investigated for both ... |
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| Pyroconvection and Climate Change |
Jan 2007 |
3 pages |
| Authors:
M Fromm; S Miller; J Turk; T Lee; NAVAL RESEARCH LAB WASHINGTON DC
|
| In March 1998, the Naval Research Laboratory (NRL) launched a satellite instrument named Polar Ozone and Aerosol Measurement (POAM) III. Just a few months after launch, POAM III started detecting mysterious clouds in the stratosphere in the sub-Arctic northern hemisphere. It was obvious that an unusual phenomenon was being recorded. We now know that these mysterious aerosol-cloud layers were smoke from forest fires that erupted like a volcano into what ... |
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| Giant Enhancement in UV Response of ZnO Nanobelts by Polymer Surface-Functionalization |
2007 |
3 pages |
| Authors:
Chang Shi Lao; Myung-Chul Park; Qin Kuang; Yulin Deng; Ashok K. Sood; Dennis L. Polla; Zhong L. Wang; GEORGIA INST OF TECH ATLANTA SCHOOL OF MATERIALS SCIENCE AND ENGINEERING
|
| Zinc oxide (ZnO) is one of the most important nanomaterials for nano-optoelectronics, sensors, transistors, and nanopiezotronics. Because of the unique piezoelectric and semiconducting dual properties, ZnO nanowires (NWs) and nanobelts (NBs) are the fundamental material for nanogenerators, which convert mechanical energy into electricity. With a band gap of ~3.4 eV and an exciton binding energy of 60 meV, ZnO has huge promise for optical applications, such as UV detection. However, ... |
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| Exploring the Temporal and Spatial Dynamics of UV Attenuation and CDOM in the Surface Ocean using New Algorithms |
Jan 2006 |
9 pages |
| Authors:
William L Miller; GEORGIA UNIV ATHENS DEPT OF MARINE SCIENCES
|
| Our long-term objective is to develop a classification for the global ocean based on surface CDOM dynamics that identify regions by variability patterns and the ability to forecast CDOM variations with a known uncertainty. The central objective of this project is to apply and refine newly developed ocean color algorithms in the examination of the variability and predictability of UV optical properties in the ocean. This includes the following supporting ... |
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| Analysis of FOVEON Multi-Spectral Sensor for Counter-Camouflage, Concealment and Deception Applications |
DEC 2005 |
67 pages |
| Authors:
Devon C. Nugent; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
|
| The research described here addresses a technology that may be useful for the defeat of camouflage, concealment, and deception (CC&D). This research aims to study a low cost and highly portable alternative to existing counter CC&D techniques. A commercial off the shelf (COTS) imagery sensor able to distinguish near-infrared (NIR), near-ultraviolet (NUV), and visible wavelengths has been studied. The FOVEON image sensor, a multi-layer focal plane technology, was used in ... |
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| On the Origins of Solar EIT Waves |
20 SEP 2005 |
9 pages |
| Authors:
E. W. Cliver; M. Laurenza; M. Storini; B. J. Thompson; AIR FORCE RESEARCH LAB HANSCOM AFB MA SPACE VEHICLES DIRECTORATE
|
| Approximately half of the large-scale coronal waves identified in images obtained by the Extreme-Ultraviolet Imaging Telescope (EIT) on the Solar and Heliospheric Observatory from 1997 March to 1998 June were associated with small solar flares with soft X-ray intensities below C class. The probability of a given flare of this intensity having an associated EIT wave is low. For example, of ~8,000 B-class flares occurring during this 15 month period, ... |
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| Tunable High efficiency Resonant Tunneling GaN/AlGaN MQW UV Detectors |
AUG 2005 |
24 pages |
| Authors:
W. B. Wang; S. K. Zhang; R. R. Alfano; CITY COLL OF THE CITY UNIV OF NEW YORK
|
| The objective of this project is to develop tunable high efficiency resonant tunneling GaN/AlGaN multiple quantum well (MQW)-based UV photodetectors. During the grant period, more than twenty six GaN/AlGaN MQW phoptodetectors with different types of device structures and control samples have been fabricated and investigated to achieve the proposed narrow band detection, high efficiency and fast response time. The research results have been published in five refereed journals, presented at ... |
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| Detection and Diagnostics of a Coronal Shock Wave Driven by a Partial-Halo Coronal Mass Ejection on 2000 June 28 |
10 MAR 2005 |
9 pages |
| Authors:
A. Ciaravella; J. C. Raymond; S. W. Kahler; A. Vourlidas; J. Li; AIR FORCE RESEARCH LAB HANSCOM AFB MA SPACE VEHICLES DIRECTORATE
|
| A fast partial-halo coronal mass ejection (CME) was observed on 2000 June 28 by instruments on the SOHO spacecraft. The CME leading edge and filamentary cold core were detected over the northwest limb at 2.32 R(circle dot solar) by the SOHO UV Coronagraph Spectrometer (UVCS). The broad profile of the O VI lambda-1032 line gives evidence of a shock front at the leading edge, supporting the identification of white-light CME ... |
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| UV Raman Detection of Chemical Agents |
DEC 2004 |
3 pages |
| Authors:
Steven Christesen; Kristina Gonser; J. M. Lochner; Arthur Sedlacek; Thomas Chyba; Daniel Sink; Jay P. Jones; Bennett Corrado; Andrew Slaterbeck; EDGEWOOD CHEMICAL BIOLOGICAL CENTER ABERDEEN PROVING GROUND MD
|
| Optical detection techniques are attractive because they are non- intrusive and. in the case of vibrational spectroscopy. highly selective. Like infrared absorption and UV fluorescence. Raman spectroscopy has advantages and limitations as a non-contact detection and identification technique. One area where it appears to be well suited is for the detection of liquid and solid contamination on surfaces. In a effort to develop a UV Raman based surface contamination detector, ... |
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| Venturing Through the Forbidden Band |
DEC 2004 |
44 pages |
| Authors:
MISSILE DEFENSE AGENCY WASHINGTON DC
|
| Over the past three decades, industry and the U.S. Government have invested hundreds of millions of dollars in an emerging area called wide-bandgap materials. The technical significance of these materials is that they can be made into semiconductor devices capable of handling much higher voltages than silicon, while withstanding and operating at much higher temperatures. Such materials also have unique optoelectronic capabilities that allow them to emit blue and UV ... |
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| Design of a Bore Sight Camera for the Lineate Image Near Ultraviolet Spectrometer (LINUS) |
JUN 2004 |
79 pages |
| Authors:
Rodrigo Cabezas; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
|
| The Lineate Image Near Ultraviolet Spectrometer (LINUS) is a spectral imager that works in the ultraviolet region of the spectrum. This thesis describes the latest of several steps in the development of this instrument. Due to the narrow field of view of the instrument, 2.5 x 0.5 degrees, an accurate pointing method is necessary; also, a scheme of quality evaluation of the post- processed spectral image is desirable. A way ... |
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| Infrared Spectroscopy of Hyper Velocity Shock |
05 MAY 2004 |
6 pages |
| Authors:
Peter Erdman; EMBRY-RIDDLE AERONAUTICAL UNIV DAYTONA BEACH FL
|
| We have continued the investigation of hypervelocity shocks that began with the highly successful Bowshock I and II atmospheric sounding rocket experiments. Instruments aboard those vehicles performed measurements of the ultraviolet and vacuum ultraviolet emission excited in the high temperature gas produced by the shock ahead of the hypervelocity body. We have developed the experimental techniques and the instruments necessary to expand those earlier experiments into the infrared portion of ... |
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| Ultraviolet CO Chemiluminescence in CH(X2II) and CH(a4sigma-) Reactions with Atomic Oxygen at 298 K |
29 MAR 2004 |
38 pages |
| Authors:
Ghanshayam L. Vaghjiani; ENGINEERING RESEARCH AND CONSULTING INC(ERC INC) EDWARDS AFB CA
|
| Production of ultraviolet CO chemiluminescence has been observed for the first time in the gas-phase pulsed laser photolysis of a trace amount of CEBr3 vapor in an excess of O-atoms. O-atoms were produced by dissociation of O2 or N2O in 4 cw-microwave discharge cavity in 2.0 torr Heat 298 K. Temporal profiles of the excited state products that formed in the photo-produced precursor + O-atom (or O2) reaction were measured ... |
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| Deep Ultra-Violet (DUV) Light Emitting Diodes |
30 AUG 2003 |
14 pages |
| Authors:
Deepika Singh; Steve Pearton; SINMAT INC GAINESVILLE FL
|
| Problems to Overcome: The main problem to overcome is to develop a commercially and economically viable method to synthesize and process high crystalline quality diamond films for applications such as DUV LEDs and solar- blind detectors. Scientific Approach: The scientific approach is the homoepitaxial deposition on diamond films on large area (50 - 100 sq mm) synthetic Type Ib diamond substrates. Although type Ib diamond substrates have a high nitrogen ... |
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| Contacts to AlGaN for UV Detectors |
31 MAR 2003 |
30 pages |
| Authors:
Suzanne E. Mohney; PENNSYLVANIA STATE UNIV UNIVERSITY PARK OFFICE OF SPONSORED PROGRAMS
|
| Electrical contacts to AlGaN were investigated at The Pennsylvania State University. |
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| Ultraviolet-spectrum Light-emitting Diodes with Omnidirectional Reflectors for High Extraction Efficiency |
10 FEB 2003 |
4 pages |
| Authors:
E. F. Schubert; BOSTON UNIV MA
|
| This report covers the period August 1st to August 31st 2002 while I was working for Boston University (BU). On September 1st I transferred to Rensselaer Polytechnic Institute (RPI). It is my understanding that this report is required for the transfer of the contract from BU to RPI. The reflective properties of a triple-layer omni-directional reflector have been investigated. The reflector has a two-fold purpose namely it serves as ohmic ... |
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| Remotely Sensed Density Measurements of Volcanic Sulfur Dioxide Plumes Using a Spectral Long Wave Infrared Imager |
SEP 2002 |
146 pages |
| Authors:
Aimee G. Mares; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
|
| This thesis examines the process of detecting and quantifying volcanic SO2 plumes using the Airborne Hyperspectral Infrared Imager (AHI) developed by the University of Hawaii, AHI was flown over Pu'u'O'o Vent of Kilauea Volcano in Hawaii to collect data on 502 plumes. In conjunction with these observations, data were taken with the Hawaii Volcano Observatory's Correlation Spectrometer (COSPEC) and University of Hawaii's FLYSPEC. These are ultraviolet remote sensors with a ... |
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| Experimental and Analytical Development of Kinetic Rate Data for Radiating Rocket Plume Species |
01 JUL 2002 |
86 pages |
| Authors:
E. Ploenjes; P. Palm; I. Adamovich; W. Lempert; V. Subramaniam; OHIO STATE UNIV COLUMBUS DEPT OF MECHANICAL ENGINEERING
|
| The report presents results of experimental and analytical studies of certain energy transfer mechanisms and rates in high-energy gas flows. The immediate application is to generate kinetic data to aid in the prediction of the radiation emitted by hypervelocity vehicle flowfields, radiation from high altitude rocket plumes, how shocks, and shock layers around the vehicles. The present report gives data on a newly discovered vibration-to-electronic (V-E) energy transfer process in ... |
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| Predicting the UV Exposure at Philadelphia, PA |
JUL 2002 |
14 pages |
| Authors:
James R. Slusser; COLORADO STATE UNIV FORT COLLINS COLL OF FORESTRY AND NATURAL RESOURCES
|
| The Naval Surface Warfare Center has materials exposed for outdoor weathering and exposure at three sites: Philadelphia, PA; Miami, FL; and Wittman, AZ. The Miami, FL and Wittman, AZ test sites are run by Atlas Weathering Service and are instrumented to measure UV-A plus UV-B solar radiation using the Eppley TUVR. Since there is no Eppley TUVR at Philadelphia, PA, an estimate is made of the radiation a TUVR would ... |
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| III-Nitride UV Detector Arrays Fabricated by Combining HVPE Lateral Epitaxial Overgrowth and MBE Methods |
15 MAY 2002 |
36 pages |
| Authors:
Theodore D. Moustakas; BOSTON UNIV MA DEPT OF ELECTRICAL AND COMPUTER ENGINEERING
|
| The work focused on the fabrication of GaN and AlGaN detectors. Material studies of AlGaN alloys have been undertaken to improve the absorption characteristics and to develop films free of cracks. The devices were fabricated in the form of Schottky barriers, p-n and p-i-n junctions. To reduce the dark current in these devices, a number of approaches were investigated (use of thick GaN templates grown by the HVPE and the ... |
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| Absolute Calibration Techniques for UV Spectroscopy Based Upon Platinum Emission Line Spectra |
DEC 2001 |
83 pages |
| Authors:
Daniel W. Kuriger; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
|
| Imaging Spectrometry requires precise knowledge or wavelength in order to perform various spectral analyses. This thesis project was tasked with performing wavelength calibration as part or the ongoing development or the Naval Postgraduate School's Lineate Imaging Near Ultraviolet Spectrometer (LINUS). This calibration was necessary for the ability or LINUS to detect, to classify, sod to quantify several different chemical species by observation over the near-ultraviolet wavelength band or 200 to ... |
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| Investigation of III-Nitride Alloys for Ultraviolet Photodetectors and Blue-Green Lasers |
AUG 2001 |
29 pages |
| Authors:
NORTHWESTERN UNIV EVANSTON IL CENTER FOR QUANTUM DEVICES
|
| This AASERT contract was intended to support one graduate and one undergraduate students for three years, with the objective of conducting research work on the growth and characterization of wide bandgap GaN based semiconductors for ultraviolet photodetectors and visible light emitters. The research was directed toward optimizing the metalorganic chemical vapor deposition (MOCVD) growth and characterization of undoped, n-type and p-type doped wide bandgap GaN and AlxGa1-xN semiconductors, for x ... |
|
| Electronic Warfare (EW) Receiver and Processing Concepts Evaluation Program (RAPCEval 2) |
MAY 2001 |
182 pages |
| Authors:
W. T. Bass; MERCER ENGINEERING RESEARCH CENTER WARNER ROBINS GA
|
| The EW Receiver and Processing Concepts Evaluation Program (RAPCEval2) tasks have provided analytical support for current research for the Electronic signal Measurement (ESM) group at Air Force Research Laboratory (AFRL). Tasks initiated under OPTION 3 of the contract of this program provided analysis for inputs and countermeasures for electronic receivers of radar, electro-optic, infrared, and ultraviolet systems. Research has been performed under the direction of the Joint Program Research Standards ... |
|
| Electronic Warfare (EW) Receiver and Processing Concepts Evaluation Program (RAPCEval 2) |
JUL 2000 |
327 pages |
| Authors:
W. T. Bass; MERCER ENGINEERING RESEARCH CENTER WARNER ROBINS GA
|
| EW Receiver and Processing Concepts Evaluation Program (RAPCEval 2) tasks have provided analytical support for current research for the Electronic Signal Measurement (ESM) group at Air Force Research Laboratory. Tasks initiated under OPTION 3 of the contract of this program provided analysis for inputs and countermeasures for electronic receivers of radar, electro-optic, infrared, and ultraviolet systems. Research has been performed under the direction of the Joint Program Research Standards Committee, ... |
|
| Regional Mapping of the Coastal Zone with Airborne LIDAR |
Jan-2000 |
3 pages |
| Authors:
Jennifer M Wozencraft; Jennifer L Irish; CORP OF ENGINEERS MOBILE AL JOINT AIRBORNE LIDAR BATHYMETRY TECHNICAL CENTER OF EXPERTISE
|
| Recent advancements in lidar sensors now allow for near-synoptic, regional-scale mapping of the coastal zone. One such sensor is the U.S. Army Corps of Engineers SHOALS (Scanning Hydrographic Operational Airborne Lidar Survey) system. SHOALS is unique in that it is the only lidar sensor, worldwide, that simultaneously collects bathymetry and adjacent topography. Because of SHOALS' high collection rate, data density, and system accuracy, it is now cost effective to quantify ... |
|
| ISTEF Passive Imaging Programs |
22 JUL 1999 |
25 pages |
| Authors:
Alan Tietjen; Jodean Wendt; Jonathan Emery; Don Dawson; Rolf Ahlgreen; NICHOLS RESEARCH CORP ORLANDO FL
|
|
| Electronic Warfare (EW) Receiver and Processing Concepts Evaluation Program (RAPCEval 2) |
JUL 1999 |
341 pages |
| Authors:
W. T. Bass; MERCER ENGINEERING RESEARCH CENTER WARNER ROBINS GA
|
| EW Receiver and Processing Concepts Evaluation Program (RAPCEval 2) tasks have provided analytical support for current research at the ESM group at Air Force Research Laboratory. Tasks initiated under OPTION 1 of the contract of this program provided analysis for inputs and countermeasures for electronic receivers of radar, electro-optic, infrared, and ultraviolet systems. Research has been performed under the direction of the Joint Program Research Standards ... |
|
| Multi-Spectral Shocklayer Radiance from a Hypersonic Slender |
1999 |
15 pages |
| Authors:
Deborah A. Levin; David M. Mann; Clifton B. Phillips; Mike Lovern; Carl Howlett; GEORGE WASHINGTON UNIV WASHINGTON DC
|
| The Science and Technology Directorate of the Ballistic Missile Defense Organization is conducting programs to characterize and measure the radiation emitted by the flows about hypersonic vehicles. In addition to understanding the basic physics of high temperature plasmas, ongoing analyses are establishing how such emissions are useful for the detection of theater missile targets using the mid-wave infra-red (MWIR) spectral region (3 - 5 ... |
|
| Modeling Infrared Glow Above Thunderstorms |
23 DEC 1998 |
10 pages |
| Authors:
Peter P. Wintersteiner; ARCON CORP WALTHAM MA
|
| An investigation of the effect of thundercloud charging on electric fields in the middle atmosphere has led to the prediction that heating of electrons in the D-region should occur over time scales of minutes or longer. We have studied the effect of this heating on the excitation of vibrational states of N2 and CO2. Because of the quasi-steady nature of the excitation, it is possible to perform radiative-transfer calculations and ... |
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| Research Related to the Development, Fabrication and Characterization of UV Detectors and Cold Cathode Devices |
DEC 1998 |
25 pages |
| Authors:
R. F. Davis; E. Carlson; T. Gehrke; A. D. Hanser; P. Hartlieb; NORTH CAROLINA STATE UNIV AT RALEIGH DEPT OF MATERIALS SCIENCE AND ENGINEERING
|
| Pendeo-epitaxial growth of GaN films has been investigated as a function of growth temperature on etched, elongated GaN seed columns grown on AlN/6H-SiC (0001) substrates via metalorganic vapor phase epitaxy (MOVPE). Silicon nitride mask layers atop the GaN seed columns forced growth from the sidewalls of the columns. Higher growth temperatures resulted in improved coalescence due to greater lateral-to-vertical growth ratios. Thin films of AlN and GaN were also deposited ... |
|
| Correlated UV Through IR Signature Modeling of Targets and Backgrounds |
NOV 1998 |
11 pages |
| Authors:
John M. Stewart; Robert W. Goodwin; Melinda K. Higgins; Ed M. Patterson; GEORGIA INST OF TECH ATLANTA
|
| Simulations of the performance of multi-spectral sensors or multiple sensors with data fusion require phenomenological consistency in the target and background signatures presented to the sensors. This paper describes the incorporation of ultraviolet signatures of targets and backgrounds into an engagement simulation framework. This paper emphasizes ultraviolet phenomenology and the signatures of aircraft compared to fires, lights, industrial sources and other high energy sources. In particular, variation of the sources ... |
|
| Solid-State Laser Source of Tunable Narrow-Bandwidth Ultraviolet Radiation |
28 APR 1998 |
|
| Authors:
Lew Goldberg; Dahv A. Kliner; Jeffrey P. Koplow; HARVARD COLL CAMBRIDGE MA PRESIDENT AND FELLOWS
|
 | A solid-state laser source of tunable and narrow-bandwidth UV light is disclosed. The system relies on light from a diode laser that preferably generates light at infrared frequencies. The light from the seed diode laser is pulse amplified in a light amplifier, and converted into the ultraviolet by frequency tripling, quadrupling, or quintupling the infrared light. The narrow bandwidth, or relatively pure light, of the seed laser is preserved, and ... |
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| Research Related to the Development, Fabrication and Characterization of UV Detectors and Cold Cathode Devices |
DEC 1997 |
48 pages |
| Authors:
R. F. Davis; NORTH CAROLINA STATE UNIV AT RALEIGH
|
| The microstructure and the mechanism of lateral epitaxy overgrowth (LEO) of homoepitaxially and selectively grown GaN pyramid structures on GaN/ AlN/6H-SiC(0001) substrates and within windows in SiO2 masks have been investigated by transmission electron microscopy (TEM) and scanning electron microscopy (SEM). The structures were produced by organometallic vapor phase epitaxy (OMVPE) for field emission studies. The SiO2 film provided an amorphous stage on which lateral growth of the GaN occurred. ... |
|
| Design, Construction, and Operation of the Naval Postgraduate School's Ultraviolet Imaging Spectrometer (NUVIS) |
DEC 97 |
91 pages |
| Authors:
Todd A. Hooks; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
|
| Hyperspectral imaging spectrometers produce an image, comprised of the standard two dimensional spatial scene and the corresponding spectra of each scene. Hyperspectral imaging is a relatively new and fast growing field with both commercial and military applications. Commercial applications vary from vegetation identification and mapping, surface geological identification and mapping to atmospheric composition and mapping. Military applications include target identification and classification, airborne chemical identification and mapping, and rocket plume ... |
|
| Ionospheric Profiles from Far Ultraviolet Remote Sensing: The Forward Model |
OCT 97 |
11 pages |
| Authors:
A. Tan; ALABAMA A AND M UNIV NORMAL
|
| Ultraviolet remote sensing of the ionosphere - The goal of this project is to faithfully reconstruct ionospheric profiles from O+ - e- recombination emissions in the far ultraviolet region of the electromagnetic spectrum as observed from polar orbitting space platforms. The nighttiine ionsophere - Remote sensing of the nighttime ionosphere is a more straightforward process because of the absence of the complications brought about by daytime solar ultraviolet radiation. This, ... |
|
| Semiconductor Ultraviolet Detectors |
25 APR 97 |
33 pages |
| Authors:
P. I. Cohen; M. I. Nathan; MINNESOTA UNIV MINNEAPOLIS DEPT OF ELECTRICAL ENGINEERING
|
| Materials and structures crucial to the development of semiconducting ultraviolet detectors were examined. The chemical beam epitaxy of GaN was compared to the growth of GaN using supersonic jet sources. The main characterization techniques employed were reflection high energy electron diffraction (RHEED) and desorption mass spectroscopy (DMS). It was found that a supersonic jet of molecular nitrogen seeded in molecular hydrogen would react at the surface to form GaN at ... |
|
| Installation Restoration Research Program: Simplified Concepts in Spectroscopy and Photochemistry |
APR 97 |
86 pages |
| Authors:
Mohammed Qasim; ARMY ENGINEER WATERWAYS EXPERIMENT STATION VICKSBURG MS
|
| Spectrophotometric techniques are powerful tools for determining both qualitative (including structural) and quantitative changes in organic and inorganic compounds, and these techniques are particularly useful for studying: concentration changes; solvent effects; the excited states of certain molecules; trends in ultraviolet (UV) and visible (VIS) spectral changes (due to such structural changes as the addition of electron donating or withdrawing groups to aromatic compounds or to the extension of pi system ... |
|
| Influence of the STS-78 Space Shuttle Exhaust Plume on Column Ozone Abundance Inferred from Ground-level Solar UV Spectra |
15 FEB 97 |
19 pages |
| Authors:
D. J. McKenzie; D. J. Gutierrez; J. H. Hecht; AEROSPACE CORP EL SEGUNDO CA EL SEGUNDO TECHNICAL OPERATIONS
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| The ground-based prototype of the High Resolution Ozone Imager (HIROIG), an imaging spectrograph that was operated in the wavelength range 275- 360 nm, was deployed at Kennedy Space Center on June 19-21, 1996 to make observations before, during, and after the launch of the STS-78 space shuttle mission. The instrument measured the ultraviolet (UV) spectrum of direct sunlight at the ground every 74 s for several hours during each of ... |
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| Active Remote Sensing Using Ultra Broadband Radiation |
31 JAN 97 |
30 pages |
| Authors:
P. Sprangle; A. Ting; E. Esarey; R. Hubbard; B. Hafizi; NAVAL RESEARCH LAB WASHINGTON DC BEAM PHYSICS BRANCH
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| Active remote sensing using ultra broadband (UB) radiation has the potential to achieve identification of hazardous air pollutants (HAPs) at extended distances. The objective of this report is to propose and analyze the use of UB radiation for active remote sensing of HAPs. The UB source can provide day-night illumination of the pollution site with simultaneous multi-wavelength (continuum) radiation in the ultraviolet, visible or infrared regime. In addition, the UB ... |
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Ultraviolet Detection and Detectors
