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... Operations and Reports, 1215 Jeflerson Davis Highway, Suite 1204, Arlington. VA 22202-4302, and to the Office of Management and Budget, Paperwork Reduction Project (0"04-0188). Washington. DC 20503 I 9. SponsoringlMonitoring Agency Name(s) and Address(es). 10. Sponsoring/Monitoring Agency Naval Oceanographic and Atmospheric Research Laboratory Report Number. Code 200 Stennis Space Center, Mississippi 39529-5004 PR 90:019:240 11. Supplementary Notes. 12a. DistributionlAvailability Statement. 12b. Distribution Code. Approved for public release; distribution is unlimited. (13. Abstract (Maximum 200 words). ,-Recent high-frequency acoustic ocean bottom scattering developments are described. A brief summary of experiments carried out in the frequency range from 5 to 180 kHz during the 1980's is presented. These experiments were performed to identify specific scattering mechanisms leading to bottom backscattering, bottom forward loss, and sound penetration into the ocean subbottom. The capability to accurately predict acoustic scattering is addressed through model and data comparisons. Pertinent unresolved issues are discussed. -.-