Detection and Exploitation of Vibration Induced Optical Amplitude Modulation
Abstract
The remote sensing of surface vibrations on an object via optical methods has many applications. Current techniques use phase coherent methods which are difficult to apply against a noncooperative target, or one at great distances. A simple method of exploiting the apparent amplitude modulation imposed on a light beam reflecting from a vibrating surface is explored. This method requires no phase reference between source and detector, and can use reflected sunlight as its sensor beam. The design and construction of an experimental receiver is presented, and its sensitivity against targets of varying reflectivity, specularity, and mechanical compliance is tested. Impact detection at a distance using this technique is demonstrated, as is identification of the impacted object from its recovered acoustic spectrum. Theoretical range curves are developed, and suggestions for additional uses of the technology are discussed.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 1985
- Accession Number
- ADA164179
Entities
People
- George R. Scott
Organizations
- Naval Postgraduate School