Image blurring of narrow laser beam transfer in ocean and through wavy sea surface

Abstract

In the detection of underwater object by air-born lidar, a narrow laser beam reflected by the sea bottom or the underwater target transfers in the ocean and refracted through the wavy sea surface, then received by the receiver carried by plane over the sea surface. Because of the scattering by the suspended particles and the effect of the wavy sea surface, the received signal will to some extent blurred, which will greatly decrease the image quality of the lidar system. Computer simulation by Monte Carlo method was employed to describe the process of narrow laser beam transferring in the ocean and refracted by the wavy sea surface. As the result, the intensity distribution on the receiver can be got as well as the property of image blurring after transferred thought the ocean water and refracted through the wavy sea surface. The relations between this property and the optical property of seawater, the wind speed above the sea surface were analyzed.