|Coastal seabed tomography by inversion of drifting acoustic buoys data|
Hermand, J.-P.; Absil, F.G.J. (2001). Coastal seabed tomography by inversion of drifting acoustic buoys data. J. Acoust. Soc. Am. 110(5): 2723
In: Journal of the Acoustical Society of America. American Institute of Physics: New York, etc.. ISSN 0001-4966, more
|Authors|| || Top |
- Hermand, J.-P.
- Absil, F.G.J.
A buoy field, specifically designed for shallow-water acoustic tomography, was deployed in a complex coastal environment on the western Sicilian shelf (enverse 97, Saclant Undersea Research Centre). Eight buoys drifted away from a fixed sound source receiving its repeated, broadband transmissions on their single hydrophone at fixed depths and known positions (DGPS). The 1-day run sampled, over kilometers, the acoustic impulse response (the Green’s function) of the environment as a function of range and azimuth from the source. In this paper, the mapping of sediment properties and bottom types from the ‘‘synthetic horizontal aperture’’ measurements is investigated. Statistical analyses of the frequency-dependent, mode interference patterns associated with the buoy tracks allow to isolate range-azimuth sectors of limited acoustic variability and to define regions of similar bottom conditions. Average geoacoustic parameters of these regions are determined by maximizing the processing gain of a model-based matched filter receiver [J.-P. Hermand, IEEE J. Oceanic Eng. 24, 41–66 (1999)]. The preliminary inversion results, including P-wave speed and thickness of the sediment cover, are congruent with the ground truth of a dense grid of seismic reflection profiles and sediment cores (enverse 98).