Degree Type

Dissertation

Date of Award

1989

Degree Name

Doctor of Philosophy

Department

Engineering Science and Mechanics

First Advisor

Anna L. Pate

Abstract

Source radiation analysis frequently involves characterization or identification of sound sources and fields. In order to effectively perform source radiation analysis, an integrated acoustical imaging system including software and hardware was developed based on spatial transformation. This system utilizes measurements of the complex sound field over a two-dimensional hologram surface with the one-microphone sequential sampling method. Four spatial transformation techniques, i.e. direct convolution, two-dimensional fast Fourier transform, Gauss-Hermite decomposition, and singular value decomposition, were implemented to project the hologram data to desired locations in the three-dimensional space. In addition, four new approaches based on feedback iteration concepts, with the variations of optimization and constraints, were developed to deal particularly with the ill-posed nature encountered in the backward reconstruction of source images;The theoretical background, numerical or experimental investigations, and applicational considerations of the previously mentioned aspects are thoroughly discussed in the dissertation. The conclusions detail the significance of the research results and the future prospects for radiation analysis based on spatial transformation. The technical aspects of the experimental implementation such as a computerized data acquisition system are also included in the appendix.

DOI

https://doi.org/10.31274/rtd-180813-8903

Publisher

Digital Repository @ Iowa State University, http://lib.dr.iastate.edu/

Copyright Owner

Mingsian Robin Bai

Language

en

Proquest ID

AAI8920111

File Format

application/pdf

File Size

180 pages

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