Preliminary results of an acoustic tomography experiment (ATE-93) in the eastern Arabian Sea

Abstract

An acoustic transmission experiment was conducted in the eastern Arabian Sea by deploying two transceiver systems on deep sea moorings separatEd. by 270 km. The experiment lasted for a duration of ten days (2-12 May 1993). The acoustic transmissions took place at hourly intervals in both forward and reciprocal directions. The reception time of TR2 was slected to match the transmission time of TR1 at 00 minutes of every hour, and vice versa at 30 minutes of each hour. The transmitted signal consisted of 511 digit phase coded shift register sequences. From the measured acoustic multipath arrivals, significant peaks were identified. This information was utilised to derive the layer-wise sound speed perturbation field following generalized inverse SVD. Results from preliminary analysis showed that inversion with six energetic modes and eight eigen rays can adequately reconstruct the perturbation in six pre-set layers