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oai:www.ideals.illinois.edu:2142/72022 2023-07-11 col_2142_5131 col_2142_8888 com_2142_5130 com_2142_8887 com_2142_234

Chew, Weng C. Otto, Gregory Patrick 2014-12-16T22:23:23Z 2014-12-16T22:23:23Z 10000-01-01 1993 1993 The application of electromagnetic waves to inverse scattering problems can provide information about a distant object or allow an object to be analyzed without using invasive procedures. This dissertation develops two-dimensional theories for solving the inverse scattering problem of strong scatterers, especially metallic objects and high-contrast dielectric objects. These theories advance the solutions of nonlinear inverse problems, which are useful for practical problems. Applications requiring a full nonlinear solution include medical and geophysical settings. The work presented here uses full-wave multiple scattering solutions to completely model the wave-object interaction. This treatment allows sharp resolution capability, even though no initial guess is assumed. Both polarizations are investigated, and the solutions are found to surpass other methods for high-contrast objects. Time-harmonic data are used to reconstruct some near-resonant objects, as well as some lossy objects. Perhaps the most notable contribution of this work is the definition of a new object function, which reduces the nonlinearity between the unknown body and the scattered field it produces. To help bridge the gap between theory and application, a microwave imaging array is constructed. Then, a calibration procedure is devised to relate the measured data to the theoretical work. The successful use of experimental strong scattering data in the new algorithms reveals the benefit of the theories developed in this dissertation. Made available in DSpace on 2014-12-16T22:23:23Z (GMT). No. of bitstreams: 1 9411739.pdf: 6239805 bytes, checksum: 33331d4cfd7476a5f66926568cdbde51 (MD5) Previous issue date: 1993 Embargo set by: Seth Robbins for item 72188 Lift date: Forever Reason: Restricted to the U of I community idenfinitely during batch ingest of legacy ETDs Restricted to the U of I community idenfinitely during batch ingest of legacy ETDs U of I Only 153 p. Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1993. http://hdl.handle.net/2142/72022 (UMI)AAI9411739 Engineering, Electronics and Electrical Physics, Electricity and Magnetism Electromagnetic Inverse Scattering Problems for Strong Scatterers text Electrical Engineering Electrical Engineering University of Illinois at Urbana-Champaign Dissertation Ph.D.