ACOUSTIC TRAVEL TIME COMPUTATION BASED ON PE SOLUTION

We propose the modal spectrum of the PE field (MOSPEF) method for computing modal travel time under strong mode coupling environments. Instead of dealing with the coupled equations governing the complex modal amplitudes, the coupled modal amplitudes and phases are obtained from the spectral expansion of the full wave field given by the PE solution. Consequently, the method is very efficient and is free of problems at critical coupling points. Numerical simulations for computing modal travel time perturbations caused by a mesoscale eddy are conducted. A case which illustrates the failure of the adiabatic mode theory is also presented, the result of which raises an important issue for ocean acoustic tomography schemes.