| Physics of the Geospace Response to Powerful HF Radio Waves |
31 Oct 2012 |
5 pages |
| Authors:
Evgeny Mishin; AIR FORCE RESEARCH LAB KIRTLAND AFB NM SPACE VEHICLES DIRECTORATE
|
 | This report describes the results of studies of the response of the Earth's space plasma to high-power HF radio waves from the High-frequency Active Auroral Research Program (HAARP) facility in Alaska under the 2010-2012 AFOSR task Physics of the Geospace Response to Powerful HF Radio Waves'. A first-principle model of a HF-created ionizing wave has been developed, quantitatively explaining the observed artificial plasma layers. The FLIP model has been adapted ... |
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| Joint Terminal Attack Controllers Sensors and Lasers Modernization |
Sep 2012 |
211 pages |
| Authors:
Daniel Barb; Bryan Freeman; Mark Jackson; Douglas Mount; William Newcomb; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
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| Inconsistencies exist among components of current ground targeting equipment because they were all fielded at different times and with different Concepts of Operations. This has caused an impractical design trade space resulting in unclear requirements that are inconsistent with either state of the art technology or a threat analysis of all possible combat situations. The Joint Terminal Attack Controller Sensors and Lasers Modernization capstone project was started to provide models, ... |
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| A Comparison of Ground Level Event e/p and Fe/O Ratios with Associated Solar Flare and CME Characteristics (Postprint) |
06 Mar 2012 |
22 pages |
| Authors:
S W Kahler; E W Cliver; A J Tylka; W F Dietrich; AIR FORCE RESEARCH LAB KIRTLAND AFB NM SPACE VEHICLES DIRECTORATE
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| Solar energetic particle (SEP) events reaching rigidities 1 GV are observed at 1 AU as ground-level events (GLEs). They are considered to be extreme cases of gradual SEP events, produced by shocks driven by wide and fast CMEs that are usually associated with long-duration (1 hour) soft X-ray (SXR) flares. However, some large gradual SEP events, including GLEs, are associated with flares of short-duration (1 hour) timescales comparable to those ... |
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| Hastily Formed Networks (HFN) As an Enabler for the Emergency Response Community |
Mar 2012 |
103 pages |
| Authors:
Oscar D Antillon; NAVAL POSTGRADUATE SCHOOL MONTEREY CA DEPT OF INFORMATION SCIENCES
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| The effects of natural or manmade disasters on communications infrastructures are usually so severe that emergency responders are unable to use them immediately after the disaster. To bridge this gap in communications, there is a need for a reliable technology that is not dependent on the existing infrastructure. This thesis identifies the problem of communications gaps during natural or manmade disasters and reviews the potential benefit of implementing a solution ... |
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| Investigation of Propagation in Foliage Using Simulation Techniques |
Dec 2011 |
115 pages |
| Authors:
Chung W Chan; NAVAL POSTGRADUATE SCHOOL MONTEREY CA DEPT OF ELECTRICAL AND COMPUTER ENGINEERING
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| In a foliage environment, radio wave propagation is subjected to fading on both large-scales and small-scales that impairs the quality and reliability of data link transmission. This has implications for many military operations. One example is the effects of foliage on the performance of communications links and unmanned aerial vehicle (UAV) radio links when ground forces are operating in foliage environments. The purpose of this research is to evaluate some ... |
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| Development of an Indium Gallium Arsenide (InGaAs) Short Wave Infrared (SWIR) Line Scan Imaging System |
Sep 2011 |
50 pages |
| Authors:
David Y Chiu; Troy Alexander; ARMY RESEARCH LAB ADELPHI MD SENSORS AND ELECTRON DEVICES DIRECTORATE
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| This report describes the design, operation, and performance of a line scan imaging system using a one-dimensional (1-D) 256 indium gallium arsenide (InGaAs) photodiode linear array sensor that operates in the short wave infrared (SWIR) (0.8 1.7um) region. The system provides temporal profile images that show the outline, shape, size, height, and grey-shades of moving objects at a distance. These profile images allow low bandwidth and low power operation for ... |
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| Characterization of Long Baseline Calibrators at 2.3 GHz |
Jan 2011 |
9 pages |
| Authors:
F Hungwe; R Ojha; R S Booth; M F Bietenholz; A Collioud; P Charlot; D Boboltz; A L Fey; NAVAL OBSERVATORY WASHINGTON DC
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| We present a detailed multi-epoch analysis of 31 potential Southern hemisphere radio calibrators that were originally observed as part of a programme to maintain the International Celestial Reference Frame. At radio wavelengths, the primary calibrators are active galactic nuclei (AGNs), powerful radio emitters which exist at the centre of most galaxies. These are known to vary at all wavelengths at which they have been observed. By determining the amount of ... |
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| Nonlinear Structuring and High-energy Electrons: Role in Ionosphere and in Thunderstorm Atmosphere Processes |
MAY 2010 |
65 pages |
| Authors:
Aleksander V. Gurevich; RUSSIAN ACADEMY OF SCIENCES MOSCOW LEBEDEV INST
|
| This report results from a contract tasking P. N. Lebedev Physical Institute as follows: The Project includes five Tasks: 1. The modification of the magnetosphere by the controllable flow of fast electrons coming upwards from the artificially modified ionosphere. Theoretical investigation and the conception of the experimental program. 2. The formation of super-narrow ionosphere structures in ionosphere artificially modified by powerful radio waves in double-resonance conditions. The super-narrow structures serve ... |
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| Creation of Artificial Ionospheric Layers Using High-Power HF Waves |
30 JAN 2010 |
5 pages |
| Authors:
T. Pedersen; B. Gustavsson; E. Mishin; E. Kendall; T. MILLS; H. C. Carlson; A. L. Snyder; AIR FORCE RESEARCH LAB HANSCOM AFB MA SPACE VEHICLES DIRECTORATE
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| We report the first evidence of artificial ionospheric plasmas reaching sufficient density to sustain interaction with a high-power HF pump beam produced by the 3.6 MW High-Frequency Active Auroral Program (HAARP) transmitter in Gakona, Alaska. The HF-driven ionization process is initiated near the 2nd electron gyroharmonic at 220 km altitude in the ionospheric F region. Once the artificial plasma reaches sufficient density to support interaction with the transmitter beam it ... |
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| Understanding and Predicting Urban Propagation Losses |
Sep-2009 |
105 pages |
| Authors:
Mark R Alexander; NAVAL POSTGRADUATE SCHOOL MONTEREY CA DEPT OF INFORMATION SCIENCES
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| Modern day warfare has presented the United States with a more technically savvy opponent in conflicts that have moved away from the traditional battlefield to the populated environment of the big city. Battle space dominance no longer refers simply to the physical nature of war, but now also encompasses a digital environment with a greater influence on Information Warfare. One of the keys to successfully maintaining open wireless lines of ... |
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| Densification of the Optical Reference Frame |
Jan-2009 |
4 pages |
| Authors:
Norbert Zacharias; Jean Souchay; Jose L Haro; David G Muinos Monet; Francois Mignard; Brian D Mason; Irina I Kumkova; Ralph A Gaume; Dafydd W Evans; Christine Ducourant; Thomas E Corbin; Beatrice Bucciarelli; William F Altena; Imants van Platais; Sean E Urban; NAVAL OBSERVATORY WASHINGTON DC
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| A continuation of this WG was voted for at the IAU GA 2006 in Prague. The International Celestial Reference Frame (ICRF) is defined by the positions of 212 distant quasars at radio wavelengths. The primary, optical reference frame is the Hipparcos Celestial Reference Frame (HCRF), which is the Hipparcos Catalog without astrometric problem stars (in: H. Rickman (ed.) 2001, Proceedings IAU XXIV General Assembly, Transactions IAU XXIVB (San Francisco: ASP), ... |
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| Interacting Coronae of Two T Tauri Stars: First Observational Evidence for Solar-Like Helmet Streamers |
2008 |
7 pages |
| Authors:
M. Massi; E. Ros; K. M. Menten; M. K Bernado; G. Torricelli-Ciamponi; J. Neidhoefer; A. Boden; D. Boboltz; A. Sargent; G. Torres; MAX-PLANCK-INSTITUT FUER RADIOASTRONOMIE BONN (GERMANY)
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| The young binary system V773 Tau A exhibits a persistent radio flaring activity that gradually increases from a level of a few mJy at apoastron to more than 100 mJy at periastron. Interbinary collisions between very large (>15 R ) magnetic structures anchored on the two rotating stars of the system have been proposed to be the origin of these periodic radio flares. Magnetic structures extended over tens of stellar ... |
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| Rotational Modulation of M/L Dwarfs Due to Magnetic Spots |
20 OCT 2007 |
5 pages |
| Authors:
C. Lane; G. Hallinan; R. T. Zavala; R. F. Butler; R. P. Boyle; S. Bourke; A. Antonova; J. G. Doyle; F. J. Vrba; A. Golden; NAVAL OBSERVATORY FLAGSTAFF AZ
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| We find periodic I-band variability in two ultracool dwarfs, TVLM 513-46546 and 2MASS J00361617+1821104, on either side of the M/L dwarf boundary. Both of these targets are short-period radio transients, with the detected I-band periods matching those found at radio wavelengths. We attribute the detected I-band periodicities to the periods of rotation of the dwarfs, supported by radius estimates and measured values for the objects. Based on the detected period ... |
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| Geospace Plasma Dynamics: Final Report (2002-2007) |
14 AUG 2007 |
30 pages |
| Authors:
Bamandas Basu; John R. Jasperse; AIR FORCE RESEARCH LAB HANSCOM AFB MA SPACE VEHICLES DIRECTORATE
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| Radar measurements of backscatter from plumes extending above the bottom side spread-F layer correlated well with observations of equatorial plasma bubbles in quiet conditions with lower correlation between scintillation and observations of plasma bubbles. DMSP satellites and the ROCSAT-1 satellite showed significantly fewer occurrences of plasma bubbles than expected near the west coast of South America and an east-west chain of GPS receivers confirms a steep longitudinal gradient in EPB ... |
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| Effects of the Rooftop Environment on GPS Time Transfer |
01 JAN 2007 |
19 pages |
| Authors:
Michael A. Lombardi; Andrew N. Novick; NATIONAL INST OF STANDARDS AND TECHNOLOGY BOULDER CO TIME AND FREQUENCY DIV
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| We examine the effects of the rooftop environment on GPS time transfer, in particular the effects of multipath reflections from nearby metallic objects. Three different antenna sites on the roof of the NIST laboratories at Boulder, Colorado, were selected, each with different multipath characteristics that we discuss. Simultaneous tests were conducted at each site with the same model of L1 band GPS receiver, but with different types of antennas. Four ... |
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| End-Pumped Monoblock Laser For Eyesafe Targeting Systems |
01 NOV 2006 |
30 pages |
| Authors:
Bradley W. Schilling; Stephen Chinn; A. D. Hays; Lew Goldberg; C. W. Trussell; ARMY BELVOIR RESEARCH DEVELOPMENT AND ENGINEERING CENTER FORT BELVOIR VA
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| We describe a next-generation monoblock laser capable of greater than 10 mJ, 1.5 8m output at 10 pulses per second (PPS) over broad ambient temperature extremes with no active temperature control. The transmitter design is based on a Nd:YAG laser with a Cr4+ passive Q-switch and intracavity KTP OPO. In order to achieve the repetition rate and efficiency goals of this effort, but still have wide temperature capability, we are ... |
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| International Seminar on The Role of Dosimetry in High-Quality EMF Risk Assessment Held in Ljubljana, Slovenia and Zagreb, Croatia on 13-15 September 2006 |
SEP 2006 |
92 pages |
| Authors:
Blaz Valic; Peter Gajsek; LJUBLJANA UNIV (SLOVENIA) INST OF NON-IONIZING RADIATION
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| Abstracts for the international seminar on The Role of dosimetry in high quality risk assessment, 13 September 2006 - 15 September 2006. In the last three decades, the use of devices that emit electromagnetic fields (EMF) has increased dramatically. The proliferation of EMF devices has been accompanied by increased concern about ensuring the safety of their use. Thus, accurate dosimetry represents an essential element of the research in determining the ... |
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| GPS Users Positioning Errors during Disturbed Near-Earth Space Conditions |
01 JUN 2006 |
15 pages |
| Authors:
E. L. Afraimovich; V. V. Demyanov; P. V. Tatarinov; E. I. Astafieva; I. V. Zhivetiev; RUSSIAN ACADEMY OF SCIENCES IRKUTSK (RUSSIA)
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| Operation quality of the Global Navigation Satellite Systems (GNSS) appreciably depends on condition of the near-Earth space environment. Afraimovich et al. (GPS Solutions, 2003, V7, N2, 109) showed, that during geomagnetic disturbances in the near space deterioration of GNSS operation quality is appeared and, as consequence, reduction of positioning accuracy and occurrence of failures in definition of ground based users coordinates are observed. Application of GNSS for the decision of ... |
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| Electromagnetic Radiation Interface System and Method |
29 SEP 2005 |
48 pages |
| Authors:
Donald H. Steinbrecher; DEPARTMENT OF THE NAVY WASHINGTON DC
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| An electromagnetic radiation interface is provided that is suitable for use with radio wave frequencies. A surface is provided with a plurality of metallic conical bristles. A corresponding plurality of termination sections are provided so that each bristle is terminated with a termination section. The termination section may comprise an electrical resistance for capturing substantially all the electromagnetic wave energy received by each respective bristle to thereby prevent reflections from ... |
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| Development of HF Ocean Radar in Japan |
14 APR 2005 |
6 pages |
| Authors:
Yukiharu Hisaki; RYUKYUS UNIV OKINAWA (JAPAN) DEPT OF PHYSICS AND EARTH SCIENCES
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| The HF ocean radar was developed in Japan from 1987 by Okinawa Radio Observatory, Communications Research Laboratory. We measured ocean surface currents and developed the method to estimate wave spectra. The observations of ocean surface currents were conducted in various areas. The observation in the east of Okinawa, where mesoscale eddies are dominant, is presented. We can observe the convergent zone associated with the front of a mesoscale eddy. Furthermore, ... |
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| Ship Echo Discrimination in HF Radar Sea-Clutter |
14 APR 2005 |
5 pages |
| Authors:
A. Bourdillon; P. Dorey; G. Auffray; UNIVERSITE DE RENNES (FRANCE)
|
| HF radar can provide Over the Horizon detection of ships on very large oceanic areas, making use of the ionospheric refraction of radio waves. The Doppler spectrum of the sea clutter is composed of the first-order Bragg lines with a second-order continuum, as described in [1] Normally the Doppler shift produces by ships is small, of the same order of magnitude of the Doppler shift of the sea clutter. Consequently, ... |
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| The Production of Near-Relativistic Electrons by CME-Driven Shocks |
2005 |
9 pages |
| Authors:
S. W. Kahler; H. Aurass; G. Mann; A. Klassen; AIR FORCE RESEARCH LAB HANSCOM AFB MA SPACE VEHICLES DIRECTORATE
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| The solar sources of near-relativistic (E >30 keV) electron events observed at 1 AU are poorly understood. In general, the solar injection times deduced from the observed 1 AU onset times and assumed 1.2 AU travel distances yield injection times about 10 minutes after the associated flare impulsive phases and type III radio burst times. One interpretation is that the apparent delays occur in the interplanetary medium, probably due to ... |
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| Simulations of Diversity Techniques for Urban UAV Data Links |
DEC 2004 |
115 pages |
| Authors:
Seng Cheong Telly Poh; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
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| In urbanized terrain, radiowave propagation is subjected to fading on large-scales and small-scales that would impede on the quality and reliability of data link transmission. This would have implications in many military applications. One example is the performance of unmanned aerial vehicle (UAV) data and communications links in complex urban environments. The purpose of this research is to study the effectiveness of diversity techniques on the performance of urban UAV ... |
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| Frequency and Polarization Diversity Simulations for Urban UAV communication and Data Links |
SEP 2004 |
|
| Authors:
Fatih Pala; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
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 | The purpose of this research was to examine the effects of frequency, and polarization on radio wave propagation in urbanized areas for unmanned aerial vehicle (UAV) data links, and command and control. The transmission from a UAV operating over a small city was simulated using the Urbana Wireless Toolset. Parameters that were varied include frequency, antenna polarization, UAV altitude, and building materials. Multiple reflections and diffractions were included in the ... |
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| Ionospheric Measurements in the Wake of Solar Maximum |
30 APR 2004 |
145 pages |
| Authors:
Angela M. Andreasen; John Begenesich; Edward Fremouw; Elizabeth Holland; Andrew J. Mazzella Jr; NORTHWEST RESEARCH ASSOCIATES INC BELLEVUE WA
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| During three years following the solar maximum of the year 2000, NorthWest Research Associates (NWRA) conducted ionospheric measurements at several Air Force research and operational locations and analyzed the data collected thereby. The measurements were performed using a variety of radiowave techniques, most involving transionospheric radio propagation, and included observations of ionospheric perturbations via high-power transmissions under the High-frequency Active Auroral Research Program (HRRRP). Notable among the instruments employed were ... |
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| A New Cyclotron Maser Mechanism Observations and Theory |
07 APR 2004 |
1 pages |
| Authors:
R. Bingham; A. Cairns; A. D. Phelps; STRATHCLYDE UNIV GLASGOW (UNITED KINGDOM)
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| We present a new cyclotron maser type instability driven by a crescent or horseshaped electron distribution function. Such distribution functions are easily created by an electron beam moving into a stronger magnetic field region, where conservation of the first adiabatic invariant causes an increase in their pitch angle. This produces a broad region on the distribution function where there is a +ve slope in the perpendicular component of the velocity ... |
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| Effects of Radio Wave Propagation in Urbanized Areas On UAV-GCS Command and Control |
DEC 2003 |
107 pages |
| Authors:
Lock W. Willy; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
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| The purpose of this research was to examine the effects of radiowave propagation in urbanized areas on unmanned aerial vehicle-ground control station (UAV-GCS) command and control. Operating at high frequency has merits of higher data rate transfer, which is crucial to support the large quantity of voice and video data to be transmitted via UAV-GCS linkage. However, high frequencies are attenuated more rapidly in lossy materials and weather. Having a ... |
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| Free-Space Imaging Technology For THz Beams |
05 SEP 2003 |
9 pages |
| Authors:
X. C. Zhang; RENSSELAER POLYTECHNIC INST TROY NY DEPT OF PHYSICS
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| Under the support from ARO (DAAD19-99-1-0333), we have obtained three major achievements, including 1 dynamic aperture for THz wave microscopic imaging (see annual report 2001), 2 using THz wave for chemical & biological sensing activities (see annual report 2002), and 3 the development of the pulsed tomographic imaging technology. In this final report, I present the recent development of our free-space THz wave imaging and its application. This report gives ... |
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| Forecasting the Nighttime Evolution of Radio Wave Ducting in Complex Terrain Using the MM5 Numerical Weather Model |
AUG 2003 |
36 pages |
| Authors:
Matthew E. Kucas; PENNSYLVANIA STATE UNIV UNIVERSITY PARK COLL OF EARTH AND MINERAL SCIENCES
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| This study tests the effectiveness of using mesoscale models to forecast operationally those atmospheric conditions that cause anomalous propagation of radio waves. Providing early warning about where and when such conditions will develop would be particularly useful for military communications. To test mesoscale models' ability to provide such early warning, the Pennsylvania State University / National Center for Atmospheric Research Fifth Generation Mesoscale Model (MM5) simulates atmospheric conditions around the ... |
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| Modified Method of Geometric Electromagnetics for the Analysis of Radio Field in Marine Tropospheric Waveguides |
11 JUN 2003 |
3 pages |
| Authors:
Anatoly Bychkov; Alexei Bychkov; SEBASTOPOL NAVY INST (UKRAINE) DEPT OFRADIO ENGINEERING
|
| The interest for practical use of tropospheric waveguides (TWG) above the sea surface is still high. This is because there are many new tools for remote sensing of the atmosphere boundary layer and efficient methods for calculation of radiowave fields. Those TWG often form over the Black Sea. |
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| Electrodynamic Model of the Receiving Antenna in Terms of a Waveguide Representation of the HF Field |
11 JUN 2003 |
3 pages |
| Authors:
Vitaly V. Khakhinov; RUSSIAN ACADEMY OF SCIENCES SIBERIAN DIV INST OF SOLAR-TERRESTRIAL PHYSICS
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| This paper is concerned with the problem of the current excitation in the receiving antenna in the HF field. The solution of the problem is performed in terms of a waveguide representation of the HF field in the spherical Earth-ionosphere waveguide. Structurally, the antenna is treated in the form of a conductor of a finite length and arbitrary configuration. |
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| Measuring Electrodynamics of the Ionosphere by Digital Ionosondes and Other HF Techniques |
20 JAN 2003 |
30 pages |
| Authors:
Bodo Reinisch; Gary Sales; MASSACHUSETTS UNIV LOWELL CENTER FOR ATMOSPHERIC RESEARCH
|
| We conducted a general investigation into radiowave propagation modeling and ionospheric structure in the equatorial region. Techniques were developed to track ionospheric bubbles that form after sunset at or near the magnetic equator. These bubbles were identified as a source of satellite scintillation at 250 MHz. Drift speeds averaging around 100 m/s were observed during the test period in South America. HF propagation on a global scale was modeled using ... |
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| Validation of the Paramaterized Real-Time Ionospheric Specification Model (PRISM) |
2003 |
101 pages |
| Authors:
Robert C. Pulliam; OHIO STATE UNIV COLUMBUS
|
| The earth's ionosphere between 60km and 1000km altitude contains a significant amount of partially ionized plasma that affects the propagation of radio waves. This plasma is created when extreme ultraviolet (EUV) light from the sun strips electrons from the neutral molecules in the Earth's atmosphere. The ionosphere's free electron density is highly variable and often unstable and can adversely affect Department of Defence systems which rely on radio wave propagation. ... |
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| HAARP Diagnostic Instruments; High Frequency Active Auroral Research Program |
DEC 2002 |
71 pages |
| Authors:
Paul A. Kossey; James C. Battis; AIR FORCE RESEARCH LAB HANSCOM AFB MA SPACE VEHICLES DIRECTORATE
|
| This report describes the suite of diagnostic instruments at a major facility for experimental radio science research, under development in Gakona, Alaska. This site is being developed as part of the High Frequency Active Auroral Research Program (HAARP). A key objective of the program is the identification and characterization of the physical processes initiated in the ionosphere and space via interactions with high power radio waves. Among these phenomena are: ... |
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| Lateral and Vertical Mixing in Marginal Seas (2001-2002). Topographic Influence on Small-Scale Oceanic Dynamics (1999-2000). Mixing, Fine-Structure and Internal Waves Near Shallow-Summit Seamounts (1997-1998) |
12 NOV 2002 |
26 pages |
| Authors:
Iossif Lozovatsky; Harindra Fernando; ARIZONA STATE UNIV TEMPE DEPT OF MECHANICAL AND AEROSPACE ENGINEERING
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| Small, fine, and meso-scale structures in deep and littoral oceans were studied using field observations, data analysis and numerical simulations. The archives of data collected by Russian oceanographers were scrutinized for data quality and posted on the web for the use of international community. Three new trans-Atlantic cruises focusing on marginal zones were organized in collaboration with Russian and Spanish scientists. The influence of topography on oceanic flows was investigated ... |
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| Applied Computational Electromagnetics Society Journal. Volume 17, Number 2 |
JUL 2002 |
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| Authors:
Atef Z. Elsherbeni; APPLIED COMPUTATIONAL ELECTROMAGNETICS SOCIETY UNIVERSITY MS
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| The Applied Computational Electromagnetics Society (ACES) Journal, hereinafter known as the ACES Journal, is devoted to the exchange of information in computational electromagnetics, to the advancement of the state-of-the art, and the promotion of related technical activities. A primary objective of the information exchange is the elimination of the need to 'reinvent the wheel' to solve a previously-solved computational problem in electrical engineering, physics, or related fields of study. The ... |
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| Upper Meter Processes: Short Wind, Waves, Surface Flow and Turbulence |
DEC 2001 |
7 pages |
| Authors:
Jochen Klinke; Xin Xhang; Bernd Jahne; SCRIPPS INSTITUTION OF OCEANOGRAPHY LA JOLLA CA VISIBILITY LAB
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| This work is an extension of the early works on measuring short wind waves that have been funded by ONR for seven years, During this seven-year period, we have collected the only available systematic set of wave slope image data from different wind/wave facilities, and built a wave-imaging buoy that extends the capability of wave imaging to the field. Our objective for this extension is to complete a detailed analysis ... |
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| Offshore Surface Surveillance with HF Radar |
16 NOV 2001 |
10 pages |
| Authors:
James M. Hendrick; NAVAL RESEARCH LAB WASHINGTON DC
|
| HF groundwave radars are routinely deployed for ocean roughness and current monitoring. These low-powered radars see ship traffic as annoyance echoes, and they employ filtering techniques to remove ship and boat echoes. A simple processor addition to such radars could provide surface target tracks out to the tens of miles distances. Neptune in the UK and the Moscow Institute of Long-Wave Radiowave Communications offer radars for harbor management and monitoring ... |
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| Passive Meteoric Synchronization of Time Scales |
01-Nov-2001 |
6 pages |
| Authors:
Ivan E Antipov; Veronika V Bavykina; Yuriy A Koval; Georgiy V Nesterenko; KHARKOV STATE UNIV (UKRAINE)
|
| A special method that allows one to get time and frequency information without radio wave transmission at the secondary point is presented. This method can be used to receive time and frequency information that is contained in the TV signal by a meteor-burst channel. |
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| Summer 2000 Student/Faculty Science Campaign, July 31-August 8, 2000 |
01 OCT 2000 |
57 pages |
| Authors:
Arnold L. Snyder Jr; NORTHWEST RESEARCH ASSOCIATES INC BELLEVUE WA
|
| The primary objective of the Summer 2000 Student/Faculty Science Campaign was to provide competitively selected university faculty and students with opportunities for upper atmospheric and space physics research involving the HAARP high frequency transmitter and associated diagnostic instrumentation located near Gakona, Alaska. This report documents the technical program and participants and includes a compilation of the Student I Faculty experiment summaries in areas ionospheric generation of ULF/ELF/VLF radiowaves, D-Region diagnostics, ... |
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| A Comparison of GPS Performance in a Scintillation Environment at Ascension Island |
SEP 2000 |
9 pages |
| Authors:
K. M. Groves; S. Basu; J. M. Quinn; T. R. Pedersen; K. Falinski; A. Brown; R. Silva; P. Ning; AIR FORCE RESEARCH LAB HANSCOM AFB MA SPACE VEHICLES DIRECTORATE
|
| Post-sunset disturbances in the equatorial ionosphere routinely cause rapid phase and amplitude fluctuations (i.e., scintillation) of radio waves propagating through the disturbed regions. The intensity of scintillations is positively correlated with the solar cycle and the associated signal fades will often exceed 20 dB at L-band frequencies during solar maximum. The effect of such an environment on the performance of GPS navigation systems is poorly understood. In March 2000 AFRL ... |
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| Throughput Maximization under Quality of Service Constraints: Determination of Optimal Offered Load in Circuit-Switched (Wireless or Nonwireless) Communication Networks (CD-ROM) |
26 JUN 2000 |
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| Authors:
Jeffrey E. Wieselthier; Gam D. Nguyen; Anthony Ephremides; NAVAL RESEARCH LAB WASHINGTON DC
|
| ELECTRONIC FILE CHARACTERISTICS: Adobe Acrobat PDF document with color. PHYSICAL DESCRIPTION: 1 computer laser optical disc (Cd-ROM); 4 3/4 in.; 13.4MB. ABSTRACT: We consider the determination of the offered load that maximizes throughput in circuit-switched multihop networks, subject to quality of service (QoS) constraints on circuit blocking probability. This problem is of interest in network design for "sizing" the service capabilities that can be provided, and thereby providing a measure ... |
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| Radio Wave Propagation in Tunnels |
15 MAR 2000 |
84 pages |
| Authors:
Jeho Lee; Henry L. Bertoni; POLYTECHNIC UNIV BROOKLYN NY
|
| This report examines the radio propagation model for narrow and long tunnels. Modal analysis is used to model the path gain in 2-D and 3-D rectangular tunnels and the coupling loss of L, T and cross tunnels. Modal attenuation is determined by the wavelength lamda and given tunnel dimension through the factor square lamda /cubic w where w is the width of tunnel, by the ... |
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| Electromagnetic Diagnostics of Atmospheric Plasmas |
MAR 2000 |
47 pages |
| Authors:
Frank T. Djuth; John H. Elder; GEOSPACE RESEARCH INC EL SEGUNDO CA
|
| This research program addresses fundamental issues related to the interaction of a high-power, high- frequency (3 - 10 MHz) radio wave with the ionosphere. Data acquired at the High-Power Auroral Stimulation (HIPAS) observatory in Fairbanks, Alaska was used to study the formation of artificial periodic inhomogeneities (API) in the lower and upper atmosphere. Quite remarkably, the API echoes are observed as low as the polar stratopause near 45 km altitude. ... |
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| Scientific and Technical Report |
MAR 2000 |
75 pages |
| Authors:
Satoru Simizu; R. T. Obermyer; S. G. Sankar; ADVANCED MATERIALS CORP PITTSBURGH PA
|
| Advanced Materials Corporation has designed and constructed a spectro-polarimetric imaging system under contract with the Department of the Army (DAAL01-98-C-0080). The unit, which we will hereafter refer to as Spectroimager II, is a versatile spectro-polarimetric video imaging system that operates in the short wave infrared region between 900 nm and 1700 nm. It is an integrated imaging system with complete electronic control and interfaced with ... |
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| Sensor and Analysis Developments for Near-Earth Plasma Density Investigations |
12 NOV 1999 |
43 pages |
| Authors:
A. M. Andreasen; E. J. Fremouw; A. J. Mazzella Jr; NORTHWEST RESEARCH ASSOCIATES INC BELLEVUE WA
|
| With the progressive increase in solar activity, effects in the near- earth space environment (space weather) are becoming more intense and variable. They are manifested as increased plasma content of the ionosphere and protonosphere and as greater variability in these regions, with impacts on Global Positioning System (GPS) navigation, radio-wave communications, and other applications. This report summarizes research performed in the second year of a contract intended to: (a) investigate ... |
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| HF-UHF Propagation Prediction Over Rough Terrain |
26 JUL 1999 |
106 pages |
| Authors:
Kamal Sarabandi; Daniel Zahn; MICHIGAN UNIV ANN ARBOR RADIATION LAB
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| In this final report a summary of our activities with regard to HF- UHF propagation prediction over rough terrain is provided. Our research activities in the HF-UHF Propagation Prediction can be categorized into three categories: (1) development of a theoretical method to predict the field propagation from a small dipole over a half-space dielectric, (2) Numerical Wavelet-based Method of Moments approach to predict the scattering ... |
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| The WIND-HAARP-HIPAS Interferometer Experiment |
22 APR 1999 |
12 pages |
| Authors:
P. Rodriguez; M. J. Keskinen; E. J. Kennedy; M. McCarrick; J. Preston; NAVAL RESEARCH LAB WASHINGTON DC PLASMA PHYSICS DIV
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| We report on the first experiment using two high power, high frequency transmitting facilities in a bistatic, interferometer mode. The HAARP and HIPAS facilities in Alaska radiated at 4525 kHz with total combined power of about 700 kW, in the direction of the WIND spacecraft. The WAVES experiment aboard WIND received the transmissions at a distance of about 25 earth radii. The experimental setup thus resembled Young's two-slit experiment. The ... |
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| Generation and Control of Artificial Large-Scale Ionospheric Turbulence |
MAR 1999 |
15 pages |
| Authors:
Lev Erukhimov; RUSSIAN ACADEMY OF SCIENCES NIZHNY NOVGOROD RADIO PHYSICAL RESEARCH INST
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| This report results from a contract tasking Radiophysical Research Institute (NTRFI) as follows: The contractor will investigate generation and control of artificial large-scale ionospheric turbulence. He shall perform threeptimary tasks as described in his proposal 1) seek to understand the generation and decay mechanisms of artificial large-scale turbulence (ALST) in the ionosphere; (2) study the relationship between ALST and artificial small-scale turbulence (ASST); and (3) investigate new methods of diagnostics ... |
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| Infrared Lasers and Millimeter Waves: The Links Between Microwaves and Laser Optics |
FEB 1999 |
457 pages |
| Authors:
Eleanor R. Adair; AIR FORCE RESEARCH LAB BROOKS AFB TX HUMAN EFFECTIVENESS DIRECTORATE
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| The goal of this project is to reconcile the guidelines for human exposure at the frequency interface (300 GHz) between millimeter waves and infrared lasers and to derive means for this reconciliation in terms of existing and proposed scientific data requirements. To this end, a two-day workshop was convened at Brooks Air Force Base on 21-22 January 1997 at which experts in the technology and biological effects of exposure to ... |
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Reports by Keyword(s)
RADIO WAVES
