High Resolution Focusing Analysis and Inversion for Small Scatterer Detection

Abstract

LONG-TERM GOAL. The long-term goal of this project is to develop software to invert acoustic data from a towed source/receiver array for simultaneous velocity analysis, detection and material characterization of small-scale (7 to 15 cm) scatterers in the shallow ocean and seabed sediments. Detection will be achieved by providing a reflector map of the target region. Material characterization is provided through estimates of angularly dependent reflection coefficients at the surface of the target over multiple angles; angle versus offset analysis provides a basis for characterizing the internal material parameters of the target. OBJECTIVES. The immediate objective is to complete the development of a computer code for towed array data that back propagates the data with a wavespeed that varies in all three spatial variables. This software is also to be integrated with software to carry out velocity analysis so that the change in wavespeed from the water column to the seabed can be properly treated. The more long-term objectives are to continue to incorporate developments in the underlying theory into the software being developed for this application. For example, the theory is currently being extended to multi-pathing---the case in which the ray trajectories from a point scatterer at depth form caustics in the subsurface, leading to multiple arrivals at the same observation point on the receiver array.

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Document Details

Document Type
Technical Report
Publication Date
Sep 30, 1999
Accession Number
ADA633834

Entities

People

  • Norman Bleistein

Organizations

  • Colorado School of Mines

Tags

Communities of Interest

  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Amplitude
  • Computer Science
  • Data Processing
  • Detection
  • Earth Models
  • High Resolution
  • Inversion
  • Materials
  • Models
  • Ray Tracing
  • Reflectors
  • Standards
  • Three Dimensional
  • Towed Arrays
  • Wave Phenomena
  • Wave Propagation
  • Wavefronts

Readers

  • Acoustical Oceanography.
  • Mechanical Engineering/Mechanics of Materials.