Abstract

Research over the last decade has led to technological advances in high frequency active and passive detection technology and signal processing. An emerging application area is the standoff detection of concealed objects such as weapons and explosives using penetrating electromagnetic radiation such as terahertz waves (THz). Here sensor arrays are employed in the near field to image the concealed objects. A new approach is investigated to improve upon methods such as Fourier inversion and sum and delay beamforming. A method based on the Minimum Variance Distortionless Response (MVDR) filter technique is developed to localize source points in the electric field coming from a subject. To pinpoint near field sources with precision, this MVDR routine calculates filter responses along a plane that has direction of arrival angle and range axes. To understand its limitations, this new method is tested for angular resolution in various directions of arrival, ranges, and SNR levels. The results show that this technique has potential to accurately detect closely spaced point sources when only a few sensors are used to collect measurements.

Library of Congress Subject Headings

Signal processing--Digital techniques--Mathematics; Imaging systems--Data processing; Sensor networks; Detectors

Publication Date

10-1-2007

Document Type

Thesis

Department, Program, or Center

Chester F. Carlson Center for Imaging Science (COS)

Advisor

Rao, Navalgund

Advisor/Committee Member

Kerekes, John

Comments

Note: imported from RIT’s Digital Media Library running on DSpace to RIT Scholar Works. Physical copy available through RIT's The Wallace Library at: TK5102.9 .H36 2007

Campus

RIT – Main Campus

Download

Share

COinS