DETECTION OF OPTICAL SIGNATURE OF SUBMARINES BY LASER TECHNIQUES
Abstract
The investigation has been directed to the detection of the 'optical signature' of submarines. The equilibrium configuration of the sea-air interface is determined by the elastic waves propagated within the water and corresponds to a surface where the pressure equals that of the atmosphere; thus, any perturbation caused by submarines, vessels, as well as winds, etc., contributes to the resultant configuration. In particular, a submarine in motion constitutes a distinct source of such waves which produces surface 'signatures' such as wakes and modifications of the mean slopes of water waves. Visual as well as radar detection of submarine wakes have been demonstrated; however, these means of detection have not proven sufficiently practical, sensitive, or reliable. It appears that, by recourse to coherent optical techniques, a greatly enhanced sensitivity may be obtained, thus opening the way to the design of field equipment with suitable operational characteristics. In the following, two approaches to the problem of detection of the optical signature by means of lasers will be described. The first is based on the measurement of optical frequency shifts produced by doppler effects, and the second is based on the use of optical intensity scatter as well as optical matching filters and electronic systems of signal-to-noise enhancement. We precede the treatment with a review of the basic theories of hydrodynamics which provide a quantitative description of the optical-signature phenomena at the sea surface.
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 01, 1966
- Accession Number
- AD0381544
Entities
People
- L. M. Vallese
Organizations
- ITT Corporation