ASA 128th Meeting - Austin, Texas - 1994 Nov 28 .. Dec 02

3aUW15. Broadband source localization in a shallow-water environment with a small bottom slope.

David P. Knobles

Robert A. Koch

Appl. Res. Labs., The Univ. of Texas at Austin, Austin, TX 78712

Results from an analysis of matched-field source localization in range and depth for a range-dependent shallow-water ocean environment are presented. The matched-field localization is based on a broadband cross-correlation technique. The measured data are the time series of acoustic arrivals that propagated to a bottom mounted array from small omnisources at a location 0.5--30 km downslope. Over these ranges the water depth was 125--180 m. The measured data contain many strong multipaths because the acoustic environment was a downward refracting water column and a seafloor with a thin sand-silt sediment over a thick limestone layer. Matching fields for the localization of the sources in the measured data were computed with a broadband adiabatic normal-mode model in the 100--500-Hz band. The presentation also includes a comparison of the measured and modeled time series as a validation of the environmental and propagation descriptions. [Work supported by the Office of Naval Research (Code 322). The data measurements were sponsored by ARPA.]

Standards Committee S2 on Mechanical Vibration and Shock. Working group chairs will present reports of their recent progress on writing and processing various shock and vibration standards. There will be a report on the interface of S2 activities with those of ISO/TC 108 (the Technical Advisory Group for ISO/TC 108 consists of members of S2, S3, and other persons not necessarily members of those committees) including a report on the activities of ISO/TC 108, including its September 1994 meeting in Berlin, Germany. Scope of S2: Standards, specifications, methods of measurement and test, and terminology in the fields of mechanical vibration and shock, and condition monitoring and diagnostics of machines, but excluding those aspects which pertain to biological safety, tolerance and comfort.