The Effect of Ray Curvature on Lloyd's Mirror Fringe Estimates and Source Localisation.
Abstract
A knowledge of the interference between direct, surface and bottom reflected rays emanating from a moving underwater source can be used to determine the source detector relative positions. Using simple ray tracing, the frequency time interference patterns for a broadband frequency source arising when the propagating medium has a piecewise linear sound speed profile are considered, and are compared with those for a constant sound speed. It is found that even small deviations from a constant sound speed can lead to a noticeably different interference fringe placement and shape, and consequently to the inferred source detector geometry. Further, comparisons of model calculations to experimentally observed fringe systems demonstrate the inadequacy of the constant sound speed model, whereas tbe use of tbe simple segmented profile is capable of replicating the observed patterns.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 1994
- Accession Number
- ADA299146
Entities
People
- P. R. Lewis
Organizations
- Defence Science and Technology Group