This item is only available for download by members of the University of Illinois community. Students, faculty, and staff at the U of I may log in with your NetID and password to view the item. If you are trying to access an Illinois-restricted dissertation or thesis, you can request a copy through your library's Inter-Library Loan office or purchase a copy directly from ProQuest.
Permalink
https://hdl.handle.net/2142/81331
Description
Title
Acoustic Coherence Imaging Through the Atmosphere
Author(s)
Benson, Jonathan William
Issue Date
2000
Doctoral Committee Chair(s)
George W. Swenson, Jr
Department of Study
Electrical Engineering
Discipline
Electrical Engineering
Degree Granting Institution
University of Illinois at Urbana-Champaign
Degree Name
Ph.D.
Degree Level
Dissertation
Keyword(s)
Physics, Acoustics
Language
eng
Abstract
"The imaging of acoustic ""scenes"" through the atmosphere is a subject with little treatment in the literature. This thesis strives to set the state of the art in this field by presenting imaging methods and their performance in the turbulent atmosphere. Both narrowband interferometry and wideband techniques that can be solved using tomographic methods are presented. An extensive series of field experiments was conducted in which multiple sensor arrays of microphones recorded the signals received from loudspeaker sources outdoors under varying atmospheric conditions. Besides providing data for characterizing the imaging performance under different conditions, the field data also allowed for measurements to be made that characterize the atmosphere itself. Methods for enhancing image quality are discussed. It is shown that the popular self-calibration family of reconstruction methods from the radio astronomy community are not applicable to the acoustic imaging case. A new method, based on estimating the intensity distribution jointly with atmospheric distortion model parameters using multiple short integration period measurements, is derived. Theoretical performance bounds in the form of the Cramer-Rao lower bound are derived, and the method is applied to both synthetic and field data. The performance of this method is encouraging."
Use this login method if you
don't
have an
@illinois.edu
email address.
(Oops, I do have one)
IDEALS migrated to a new platform on June 23, 2022. If you created
your account prior to this date, you will have to reset your password
using the forgot-password link below.
