Optical Imaging Sonar
| Autor: | R. L. Johnson, R. A. Smith, P. G. Bhuta, J. H. Cole |
|---|---|
| Rok vydání: | 1975 |
| Předmět: |
Physics
Image formation geography geography.geographical_feature_category business.industry Acoustics Physics::Optics Bragg's law Sonar Sound intensity Computer Science::Computer Vision and Pattern Recognition Nondestructive testing business Sensitivity (electronics) Sound (geography) Audio frequency |
| Zdroj: | Acoustical Holography ISBN: 9781461582182 |
| Popis: | Prior work dealing with optical imaging of sound waves was devoted to nondestructive testing applications at sound frequencies of 1 MHz and higher. Bragg diffraction of light by sound waves permits one to obtain optical images of sound fields on a real time basis. This paper describes the formation of optical images of sound fields which are at frequencies of approximately 100 KHz and higher for sonar applications. A new dual frequency optical heterodyning technique, necessary for image formation at low sound intensity and low frequencies, was devised for sonar applications. Optical images of objects insonified at a distance of 5 meters from the Bragg cell are presented. Experimental results pertaining to sensitivity measurements are given and compared with sensitivity reported for other imaging systems. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|