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Presentation Title: HF Oblique Incident Sounding for Calibration of an Over-The-Horizon Radar System Discipline: Electrical Engineering School: University of Oklahoma Student Level: Masters Presentation Type: Poster Presentation Abstract: HF Oblique Incident Sounding for Calibration of an Over-The-Horizon Radar System Z. Dunn and M. Yeary University of Oklahoma, College of Electrical and Computer Engineering

Over the horizon radar (OTHR) systems have recently garnered increased attention as cost-effective surveillance systems. OTHR systems operate by transmitting a radar signal in the HF range (3 MHz - 30 MHz) which bounces off the ionosphere, encounters a target, reflects back to the ionosphere, bounces off the ionosphere again, and returns to the OTHR's receiver. Due to the continuously changing state of the ionosphere, the exact frequency that can be reliably transmitted is continually changing. To operate an OTHR reliably, calibration must take place at regular intervals during operation. The proposed method for calibration is to use HF oblique incident sounding to find the exact frequencies that are reliably being transmitted and received at the time of broadcast. HF oblique incident sounding will broadcast a stepfunction of narrowband signals throughout the HF range, and the frequency range that returns to the receiver with the greatest amplitude will be used by the OTHR as the broadcast and monitoring frequency. The University of Oklahoma College of Electrical and Computer Engineering has experience building step-function based radar transmitter and receiver circuits which have had their operation confirmed through testing for delta-function presence in the frequency domain caused by near targets, matching the mathematical derivation of this effect. A plot of measured data with explanation and a picture of the outdoor test setup will be provided. After adapting the existing OU circuit design, a circuit that can be used for HF oblique incident sounding in a low-cost OTHR system will be constructed.

Presenter: Zachary Dunn Tribe: Citizen Potawatomi Nation Primary Email: Zachary.T.Dunn-1@ou.edu Biography Zachary Dunn attained a Bachelor of Science in Engineering Physics with a focus on Aerospace Engineering from the University of Oklahoma in May 2011. Throughout his undergraduate degree, he remained active in OU AISES, serving as webmaster for 3 years and AISES Gives Back Chair for another. As of Fall 2011, Zachary is currently serving as Treasurer and AISES Give Back Chair for OU AISES while pursuing a Master of Science Degree in Electrical and Computer Engineering at the University of Oklahoma, with a focus on radar systems.

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2011 National Conference Student Research Abstracts  
2011 National Conference Student Research Abstracts  

A comprehensive list of the student research topics that will be presented at the AISES 2011 National Conference

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