Modeling of the observed image of an object situated under the sea surface and distorted by surface waves

摘要

Abstract: We propose a method of numerical simulation of an image formation in vision systems looking through the waved water surface. The simulation of radiation propagation through the waved sea surface and sea depth is realized in ray approximation. Waviness is simulated as evolving in the time random surface with given spectrum of elevations and dispersion relation. New values of angular, energy, and polarization parameters of each ray in the beam after its refraction and reflection at a given surface point are calculated by means of Fresnel formulae. Seawater medium is split in the layers with thickness chosen from the condition that water characteristics can be considered as constant and that multiple scattering of a ray can be neglected within a layer. Attenuation of beam energy corresponds to the length of the beam path in the layer, and probability of beam scattering at a random angle within a layer is determined by phase scattering function. We have obtained numerically instantaneous and averaged over different exposition times images of 2D self-luminous and located mira made up from spokes and situated at various depths for various values of wind velocities and seawater scattering coefficients. Influence of water and waviness parameters on the image quality has been analyzed.!10