A design of the video transmission based on the underwater laser communication

Abstract

The combination of ROV and underwater camera has become a mainstream way to explore the world under water. In recent years, with the developing of underwater optics or acoustics imaging and detecting technique, it has provided a new way to explore the multidimensional information space of the ocean such as the unmanned underwater vehicles (UUV) and underwater sensor nodes. Most of these UUVs and sensors are deployed to acquire observation data such as real-time videos. Although the light can not perform the long-distance propagation like acoustic signal under water, with the high bandwidth speciality of optical communication, it is absolutely feasible to acquire a highspeed real-time video information in short rang. To achieve this goal, this paper aims to implement an underwater video transmission system based on the laser link. Because of the optical characteristic of seawater, the effect of the absorption and scattering is crucial, when applied to underwater video transmission, the signal communication distance and the bandwidth would be limited. For a color video, the visual influence of the seawater optical communication channel is mainly reflected in the video color and video resolution. In this paper the video transmission system based on the underwater laser communication link was employed. Considering of the effect of the absorption and scattering, the performance of the channel was tested through changing the tank visibility. Through the real-time video contrast and the PSNR of every frame in the video file, the communication distance measured by the visibility of different multiples was evaluated.