Verification of a New Model of the Irradiance Distribution from a Unidirectional Point Source in Water Using the Monte Carlo Method

We study the spatio-angular structure of a nonstationary light field produced in seawater by a unidirectional point source. The calculation results obtained using an analytical model, which allows for the photon spread over the propagation paths, and the statistical simulation method are compared. It is shown that the analytical model provides a good description of the amplitude-frequency characteristics of irradiance in a wide range of variation in the essential parameters of the problem, namely, the distance from the source, the angle reckoned from the radiation axis, and the frequency. Disagreement of the results of the analytical model and statistical simulation is observed at high frequencies and long distances where the approximations used during the model development are inapplicable.