The arrival time of mode one in a stochastic ocean

The travel time for end of the final finale is often used is in inversion algorithms for acoustic tomography experiments when there is impreciseness due to ship and mooring positions and/or motions. The rationale is the first mode has the maximum slowness and higher order ones must arrive earlier, so the finale must solely be composed of energy from the first mode. This places a constraint on the tomographic sections, e.g., on the summation of the ray path or mode group slownesses. In a two papers Dozier and Tappert (JASA, 1978) examined the re population of the mode space for signals propagating in a stochastic ocean described by a Garrett & Munk model for internal waves. In the limit of an energy conserving ocean, i.e. no loss through boundaries, the limit of the population goes to an equipartition population density which was verified by numerical experiments. For more realistic oceans with boundary losses, the limit is a race between loss and scattering. This complicates what can be well identified as mode one at long ranges at low SNR's. We perform a numerical experiment by spatial filtering for mode one along the range dependent path to select just its energy in the finale. Earlier NUMERICAL studies by the author, (JASA, 1998) suggests just five percent of the energy remained at one megameter ranges with a 1/2 Garrett/Munk ocean. [Work supported by ONR.]The travel time for end of the final finale is often used is in inversion algorithms for acoustic tomography experiments when there is impreciseness due to ship and mooring positions and/or motions. The rationale is the first mode has the maximum slowness and higher order ones must arrive earlier, so the finale must solely be composed of energy from the first mode. This places a constraint on the tomographic sections, e.g., on the summation of the ray path or mode group slownesses. In a two papers Dozier and Tappert (JASA, 1978) examined the re population of the mode space for signals propagating in a stochastic ocean described by a Garrett & Munk model for internal waves. In the limit of an energy conserving ocean, i.e. no loss through boundaries, the limit of the population goes to an equipartition population density which was verified by numerical experiments. For more realistic oceans with boundary losses, the limit is a race between loss and scattering. This complicates what can be well identified as...