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Full-Text Articles in Engineering
Estimating Equatorial F-Region Daytime Vertical E X B Drift Velocities From Ground-Based Magnetometer Measurements In The Philippine Longitude Sector, Shauna M. Kinkela
Estimating Equatorial F-Region Daytime Vertical E X B Drift Velocities From Ground-Based Magnetometer Measurements In The Philippine Longitude Sector, Shauna M. Kinkela
Theses and Dissertations
Ionospheric disturbances can severely impact Department of Defense (DoD) systems, such as radar. satellite. and navigation technologies. Forecasting disturbances and describing the Earth's ionosphere, in turn, relies upon innovative computer-based models that gather input parameters from ground and space-borne observations and empirical models for ionospheric drivers. Equatorial E x B drift velocities are significant input parameters that go into many ionospheric models, because they help describe vertical plasma motions near the magnetic equator. Previous work by Anderson, et al 2002 has demonstrated the ability to derive Peruvian longitude sector, daytime vertical E x B drifts from ground-based magnetometer data. The …
Comparative Study On The Use Of Coherent Radar-Derived Electric Fields Vs. Statistical Electric Fields For The Initialization Of A High-Latitude Ionospheric Model, Christopher M. Hogue
Comparative Study On The Use Of Coherent Radar-Derived Electric Fields Vs. Statistical Electric Fields For The Initialization Of A High-Latitude Ionospheric Model, Christopher M. Hogue
Theses and Dissertations
The structure and time development of the magnetosphere-ionosphere system have significant impacts on the Air Force and its mission. Specifically, an accurate knowledge of ionospheric plasma densities is important for the operation of many Air Force systems. This research analyzes plasma density structure development through comparing two distinct electric field models. The two models compared here are a commonly used statistical model created by Heppner and Maynard 1987, and a more recently developed model using real-time coherent radar measurements from the SuperDARN radar network. Ionospheric simulations were run using Utah State University s Time-Dependent Ionospheric Model (TDIM) with the two …
An Analysis Of Electromagnetic Interference (Emi) Of Ultra Wideband(Uwb) And Ieee 802.11a Wireless Local Area Network (Wlan) Employing Orthogonal Frequency Division Multiplexing (Ofdm), Juan Lopez Jr.
Theses and Dissertations
Military communications require the rapid deployment of mobile, high-bandwidth systems. These systems must provide anytime, anywhere capabilities with minimal interference to existing military, private, and commercial communications. Ultra Wideband (UWB) technology is being advanced as the next generation radio technology and has the potential to revolutionize indoor wireless communications. The ability of UWB to mitigate multipath fading, provide high-throughput data rates (e.g., greater than 100 Mbps), provide excellent signal penetration (e.g., through walls), and low implementation costs makes it an ideal technology for a wide range of private and public sector applications. Preliminary UWB studies conducted by The Institute for …
Stepped Waveguide Electromagnetic Material Characterization Technique, Sean P. Dorey
Stepped Waveguide Electromagnetic Material Characterization Technique, Sean P. Dorey
Theses and Dissertations
Electromagnetic material characterization is the process of determining the complex permittivity and permeability of a material. A new waveguide material measurement technique is developed to reduce test sample size requirements for low-frequency applications. Specifically, a waveguide sample holder having a reduced aperture is utilized to decrease the time and cost spent producing large precision test samples. This type of sample holder causes a disruption in the waveguide-wall surface currents that results in the excitation of higher-order modes. This thesis will demonstrate how these higher-order modes can be accommodated using a modal-analysis technique, thus resulting in the ability to measure smaller …