CONFERENCE PROCEEDINGS
Advanced Search >
Home > Proceedings > Volume 1700 > Article
Translator Disclaimer
16 September 1992 Classification of elastic objects by active sonar in the vicinity of shallow sea boundaries
Guillermo C. Gaunaurd; Michael F. Werby
Author Affiliations +
Proceedings Volume 1700, Automatic Object Recognition II; (1992) https://doi.org/10.1117/12.138278
Event: Aerospace Sensing, 1992, Orlando, FL, United States
Abstract
Active sonar classification of submerged elastic structures becomes increasingly difficult when the structure is close to the bottom or surface of the sea. The backscattering cross-section (BSCS) of any target, which is relatively simpler to determine in deep waters, away from boundaries, becomes substantially distorted as the structure approaches either one of these environmental boundaries. Near these interfaces the classification methodology based on echo resonances that we have used in the past (viz., Appl. Mechanics Reviews 43, 171-208, (1990)) can no longer be used. By means of the examples of a spherical shell and an elastic solid sphere insonified by plane waves, we study the above mentioned degradation in BSCS in order to assess how distant the structure should be from these boundaries before the resonance features become discernible again in the echoes, and object recognition is again possible. Our approach is based on the method of images for the construction of the appropriate Green's functions, combined with a very involved two-body scattering formulation that determines the combined T-Matrix of two insonified objects, when the T-Matrix of each individual object is known. The method is extended to the time domain. We present form-functions in the frequency domain, as well as late-time responses in the time domain for both sphere and shell as they approach the mentioned boundaries. Boundary effects seem to be confined to a 'skin layer' bounded by R <EQ 4. Within this layer the resonance features fade and are washed out in both the frequency and time domains. The formulation uses translation operators borrowed from atomic physics.
© (1992) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Citation Download Citation
Guillermo C. Gaunaurd and Michael F. Werby "Classification of elastic objects by active sonar in the vicinity of shallow sea boundaries", Proc. SPIE 1700, Automatic Object Recognition II, (16 September 1992); https://doi.org/10.1117/12.138278
PROCEEDINGS
 13 PAGES
DOWNLOAD PDF SAVE TO MY LIBRARY
SHARE
GET CITATION
< Previous Article
|
Next Article >
Advertisement
Advertisement
KEYWORDS
RELATED CONTENT
Subscribe to Digital Library
Receive Erratum Email Alert
Back to Top