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Acoustic pulses propagating in the deep ocean undergo scattering due to internal waves. The scattering effects include temporal spreading, and time-front extension in depth. Some of the scattering effects have so far been analysed using Monte Carlo runs of the Parabolic Equation (PE) method. The PE simulations however do not offer much insights into the scattering physics, with regard to how the acoustic field interacts with the different parameters of the internal wave spectrum. This work instead decomposes the pressure field into a sum of normal modes and then uses the physics based transport theory model to predict the scattering amongst modes. The model has been previously used to predict cross modal coherences and energies at individual frequencies. This paper extends the narrowband model to predict the cross-modal cross-frequency coherences, and from that the acoustic pulses. One of the challenges in applying the model to pulses, is the computational complexity involved with the large number of modes across the different frequencies. To tackle that, the model uses a wide-sense-stationary approximation for the coherences. This reduced complexity model is then used to predict the temporal and depth spreading effects in the final 0.5 s of deep water time-fronts. The model predictions are then compared with acoustic measurements during the PhilSea 2010-2011 experiment. During the experiment acoustic transmissions were made from six broadband sources. The transmissions used a centre frequency of approximately 250 Hz and bandwidth of 100 Hz. The transmission ranges varied from 129 km to 450 km. The predictions are set up for the Philippine Sea frequencies and compared with observations at the shortest, and longest ranges.
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