Seabed Geoacoustic Inversion from Long-Range Broadband Sound Propagation in the Yellow Sea.

In the summer of 1996, a joint China-U.S. underwater acoustics experiment was conducted near the geographic center of the Yellow Sea with a water depth of 75 m. Hundreds of broadband explosive sources were deployed. The seabed sound speed in this experiment has been inverted using two methods based on data-derived mode depth functions and modal arrival time differences. The seabed attenuation has been estimated from three different approaches using modal attenuation coefficients, modal amplitude ratios, and transmission loss measurements [Wan, Zhou, and Rogers, J. Acoust. Soc. Am., 128(2), 2010]. The present paper analyzes the vertical coherence of the sound propagation as a function of range and frequency. The seabed sound attenuation is inferred by minimizing the difference between the theoretical and measured vertical coherence. The seabed attenuation, inverted from long-range broadband sound propagation with different methods over a frequency range of 80-1000 Hz, can be expressed as αb = (0.34±0.02)f187±004{dB/m·kHz). [ABSTRACT FROM AUTHOR]