A Technique of Comparative Analysis of Underwater Sound Transmission Loss Curves.
Abstract
A frequent requirement in underwater acoustic experimentation and calculation is the comparison of detailed propagational loss curves. These curves may be characterized in term of three principal components: (1) A monotonic trend, generally with an exponential decay; (2) A fluctuating component that contains a high percentage of periodic variation; and (3) A random component attributable to measurement error or unexplained environmental variation. The quantitative comparisons are required to show equivalency of a theoretic and an experimental calculation, the degree to which alternative theoretic calculations agree, or equivalency of experimental replicates taken at different times. This report discusses this analysis in terms of the three components with the aid of comparative statistics. The trend analysis is accomplished with a linear regression on the logarithmically transformed range term. The residuals are examined with a turning point test and classed as systematic or random. The systematic residuals are examined with an autoregression procedure to estimate the systematic periodic component and to provide a period measure. A final turning point procedure is used to estimate the level at which systematic components have been found at a prescribed level of probability. The entire process provides a comparative analysis which is applied to several sets of experimental and theoretic acoustic data.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 28, 1983
- Accession Number
- ADA129935
Entities
People
- B. B. Adams
- G. R. Giellis
Organizations
- United States Naval Research Laboratory