Verification of the Adiabatic Invariant Approximation for Computing Effective Horizontal Sound Speeds in a Range-Dependent Environment

摘要

Use of the Adiabatic Invariant Approximation (AIA) for determining horizontal sound speeds in a range-dependent environment has been proposed recently R. C. Shockley, J. Acoust. SOC. AM. 64, 1171 (1978. Because the method provides a great savings in computer time over conventional ray-tracing techniques, it was applied to two very-long-range paths, from Perth, Australia, to Bermuda and to Fernando de Noronha (19763.0 and 14549.3 km, respectively), where measured travel times are available. Results show that the AIA method predicts effective horizontal sound speeds of 1482.3m/s and 1480.4m/s, respectively, for the two propagation paths. These results compare favorably with the measured values of 1484.7 + or - 3.7 m/s and 1480.1 + or - 0.9 m/s. (Author)