Estimation of the Stability of Acoustic Multipath in Long-Range Propagation

We present the stability estimation results of the data collected during the sound transmission experiment performed by Japan Marine Science and Technology Center (JAMSTEC) in 1996 in the western equatorial Pacific Ocean. The combined information of the amplitude and the phase was effective for identifying a ray and observing the ocean-structure change. The phases of correlated signals were very stable within 50 s not only for the paths propagated near the sound fixing and ranging (SOFAR) axis but for ones turning at about 2500 m depth. The travel time could be estimated within an error of less than 0.3 ms.