Electromagnetic and Acoustic Resonance Scattering Theory
Abstract
The excitation of the eigenfrequencies of finite radar or sonar targets, of inhomogeneities in elastic materials, of geological strata or of the entire earth by the impact of propagating waves (of electromagnetic or acoustic nature, or of ultrasonic, elastic, or seismic character, respectively) manifests itself in the appearance of poles in the resulting wave amplitudes, as described by the Resonance Scattering Theory (RST). In the complex frequency plane, these poles relate to the ringing of the scattered resonances. In the complex mode number plane, corresponding poles are connected with circumferential or creeping waves. An analytics relation between these two descriptions is indicated here, and a number of examples from the above-mentioned fields will be discussed. We introduce the concepts of "Acoustic Spectroscopy" and of "Radar Spectroscopy," respectively, by exhibiting the target's resonance frequency spectrum in a form familiar from atomic spectroscopy, in order to study the shifting and splitting of resonances "levels" under changes of target shape, and to provide us with possible solutions for the "inverse problem" (i.e. determination of target properties from echo properties - here, resonant echoes).
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1983
- Accession Number
- ADA134526
Entities
People
- A. Nagl
- D. Brill
- E. Rosario
- G. C. Gaunaurd
- G. Igiri
- H. Ueberall
- J. D. Alemar
- J. D. Murphy
- J. V. Subrahmanyam
- P. J. Moser
- P. P. Delsanto
Organizations
- University of Puerto Rico at Mayaguez