ASA 130th Meeting - St. Louis, MO - 1995 Nov 27 .. Dec 01

3aAO8. Simulations of acoustic tomography of ocean currents in a coastal region.

Oleg A. Godin

NOAA/Atlantic Oceanographic and Meteorological Lab., 4301 Rickenbacker Cswy., Miami, FL 33149

Dmitry Yu. Mikhin

P. P. Shirshov Oceanogr. Inst. of the Russian Acad. Sci., Moscow 117851, Russia

A new, full field approach to acoustic monitoring of currents in the ocean---matched nonreciprocity tomography (MNT)---was recently put forward [Godin et al., in Full Field Inversion Methods in Ocean and Seismo-Acoustics, edited by O. Diachok et al. (Kluwer, Dordrecht, 1995), pp. 261--266]. The approach is based on inverting nonreciprocity in phase of a cw signal measured at a set of points in a given vertical plane. MNT was designed to overcome the problems with rays resolution and identification which make the traditional current tomography technique inapplicable in coastal regions. Results of numerical simulations of suggested MNT field experiments in the Strait of Florida will be presented. The possibility to increase resolution and robustness of the inversion with few transceivers by using wideband signals is considered. The amount of a priori environmental information required for an unambiguous currents inversion by MNT is evaluated. The possibility of simultaneous measurements of both horizontal components of current velocity is also addressed. Finally, the effects of surface and internal waves on the acoustic monitoring of ocean currents are analyzed. [Work supported by NRC and RBRF.] [sup a)]On leave from P. P. Shirshov Oceanography Institute, Moscow, Russia.