ASA 127th Meeting M.I.T. 1994 June 6-10

4pUW21. A ray travel time inversion scheme. Part II. Applications.

I-Tai Lu

Naval Res. Lab., Washington, DC

The inversion scheme reported in the companion paper is employed to analyze the data collected in the ICESHELF-89 experiment. Using the first SUS short data and assuming a range-independent environment, the location of the source and array and the sound-speed profiles have been obtained [J. W. Wolf, J. Acoust. Soc. Am. 94, 1769 (A) (1993)]. Here, not only the first shot is considered, but also other shots with larger separations between sources and receivers. For the first shot data, the same results are derived as reported when assuming a range-independent environment. However, the approach is two to three orders more efficient, due to the advantages discussed in the companion paper. Moreover, a better agreement is obtained between the simulated and the observed travel times if the water channel is allowed to have a sloping bottom. For other shots where the environment is strongly range dependent, this approach can still be applicable. The location of the source, the position of the array, the sound-speed profile in water, and the bathymetry are obtained. [Work supported by ONR and NRL.] [sup a)]On sabbatical leave from Polytech. Univ., Route 110, Farmingdale, NY 11735.

Standards Committee S3 on Bioacoustics. The current status of standards under preparation will be discussed. In addition to those topics of interest, include hearing conversation, noise, dosimeters, hearing aids, etc., consideration will be given to a new standards which might be needed over the next few years. Open discussion of committee reports is encouraged.The international activities in ISO/TC 43 Acoustics, and IEC/TC 29 Electroacoustics, and ISO/TC 108/SC4 Human Exposure to Mechanical Vibration and Shock, will also be discussed. The Chairs of the U.S. Technical Advisory Groups for ISO/TC 43 (H. E. von Gierke), and IEC/TC 29 (V. Nedzelnitsky), will report on current activities of these Technical Committees and Subcommittees.SCOPE OF S3: Standards, specifications, method of measurement and test, and terminology in the fields of mechanical shock and physiological acoustics, including aspects of general acoustics, shock, and vibration which pertain to biological safety, tolerance, and comfort.

Standards Committee S1 on Acoustics. Working group chairs will report on their preparation of standards on methods of measurement and testing, and terminology, in physical acoustics, electroacoustics, sonics, ultrasonics, and underwater sound. Work in progress includes measurement of noise sources, noise dosimeters, integrating sound-level meters, and revision and extension of sound level meter specifications. Open discussion of committee reports is encouraged.The international activities in ISO/TC 43 Acoustics, and IEC/TC 29 Electroacoustics, will also be discussed. The chairs of the respective U. S. Technical Advisory Groups for ISO/TC 43 (H. E. von Gierke), and IEC/TC 29 (V. Nedzelnitsky), will report on current activities of these Technical Committees.SCOPE OF S1: Standards, specifications, methods of measurement and test and terminology in the field of physical acoustics including architectural acoustics, electroacoustics, sonics and ultrasonics, and underwater sound, but excluding those aspects which pertain to biological safety, tolerance, and comfort.