Accession Number:

ADA609791

Title:

Numerical Studies of Rough Surface Scattering Models

Descriptive Note:

Corporate Author:

WASHINGTON STATE UNIV PULLMAN SCHOOL OF ELECTRICAL ENGINEERING AND COMPUTER SCIENCE

Personal Author(s):

Report Date:

2000-09-01

Pagination or Media Count:

4.0

Abstract:

LONG-TERM GOALS. To develop a practical set of rough surface scattering strength equations for use in real-world Navy applications. OBJECTIVES. To examine and develop theoretical surface scattering models that accurately predict acoustic wave scattering at the air-sea interface and at the ocean-bottom interface. APPROACH. We have focused our attention on the development and examination of two theoretical models, the small slope approximation SSA and the nonlocal small slope approximation NLSSA. This year development of the SSA has been for Biot theory. The initial work was done by Taiqian Yang, an assistant professor at Central Washington University and a former Ph.D. student of the PI, and recently the work has been continued by Cristina Fetche, a current Ph.D. student of the PI, under the supervision of the PI. Development of the NLSSA has been for scattering at low forward grazing angles for the airsea interface problem. This work has been done by the PI. WORK COMPLETED. Considerable work was done on the SSA for Biot theory. Since we were unable to find anything in the published literature on rough surface scattering models for Biot theory, all the underlying rough surface scattering equations had to be obtained prior to derivation of the SSA equations. This was done with the assistance of some unpublished notes by Jim Grochocinski of Corning who had worked previously with Darrell Jackson of the University of Washington Applied Physics Laboratory. These notes and Jims comments helped a great deal and allowed us to derive the underlying equations more quickly than we otherwise could have done. The rough surface scattering equations for the SSA were then derived, followed by derivation of the lowest-order SSA reflection coefficient, backscattering coefficient, and scattering strength. This past summer, code was written and numerical results were obtained for the reflection coefficient and backscattering coefficient.

Subject Categories:

  • Physical and Dynamic Oceanography
  • Test Facilities, Equipment and Methods
  • Acoustics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE