Acoustic communication channel modeling for the Baltic Sea

A physics-based numerical propagation model which includes the effects of multipath spread and Doppler spread is currently being developed as a prediction and analysis tool for underwater acoustic communication problems. The model uses three-dimensional Gaussian beams and quadrature detection to obtain the channel response for finite-duration constant-wavelength tones. By using a very short pulse, the output of the quadrature detector represents an estimate of the band-limited channel impulse response, which may be used to determine the multipath spread. In addition, the Doppler shifts associated with source/receiver motion can be accumulated from the individual beams, providing Doppler spread. The usefulness of the model for experiment planning is demonstrated for a shallow-water Baltic Sea test site. The fidelity of the model is tested via a comparison of simulated channel responses with those measured in the Baltic Sea test