Dmitry Yu. Mikhin
Sergey V. Burenkov
Yury A. Chepurin
Valerii V. Goncharov
Vladimir M. Kurtepov
Viktor G. Selivanov
P. P. Shirshov Oceanogr. Inst. of the Russian Acad. Sci., Moscow 117851, Russia
Oleg A. Godin
NOAA/Atlantic Oceanographic and Meteorological Lab., Miami, FL 33149
A moving ship tomography experiment was carried out in the Western
Mediterranean in 1994. Broadband sound signals were emitted by six moored
transceivers deployed by IfM (Kiel, Germany), IFREMER (Brest, France), and WHOI
(Woods Hole, USA), in the framework of the THETIS--2 project and recorded at a
hydrophone deployed from a drifting research vessel. The acoustic measurements
were supplemented with a detailed CTD survey. The data processing technique used
made it possible to compensate for the Doppler shift due to vessel drift,
measure the channel pulse response and estimate the arrival angles of different
rays. The arrival pattern proved to be consistent with numerical predictions
using adiabatic normal modes and ray theory. The first results of tomographic
inversion for a single vertical slice are presented. The travel times of early
raylike arrivals and final cutoffs constitute the data set for inversion. For
distances over 300 km, late modal arrivals were resolved, identified and
incorporated into the data set. An alternative inversion approach based on
matching the overall arrival pattern is discussed and compared with traditional
schemes. [Work supported by ISF, INTAS, and RBRF.] [sup