Near-infrared polarised light transmission characteristics in complex multilayer sea fog environments

Abstract Sea fog particles have a serious impact on light wave propagation, resulting in low contrast and unrecognisable intensity images, which adversely affect transportation, marine fishing and development projects, as well as military activities. In this paper, a T-matrix-based transmission model is established to simulate polarised light. Using the polarised transmission model and a multi-layer sea fog simulator, the effects of different polarisation states, different wavelengths and different salinities on the degree of polarisation are investigated in multi-layers of different media and 14 cases of optical thickness. The results show that it is more difficult to depolarise circularly polarised light than linearly polarised light at the same sea spray optical thickness. The DOP(Degree of polarization) of near-infrared light is always greater than that of visible light, indicating that circularly polarised light is more polarisation preserving than linearly polarised light, and that the polarisation preserving properties of near-infrared light are better than those of visible light.