The Research On The Underwater Contactless Information Transmission Technology For Deep Seafloor Observatory Network

The international competition for deep sea is becoming fierce more and more. Some developed countries have invested huge funds to build the deep seafloor observatory networks for long-term observation in deep sea. China carried out the research on the deep seafloor observatory network in 2007. The object of this paper is the contactless information transmission technology for deep seafloor observatory network.In order to make various varieties of sensor systems connecting the ocean observing network independent and easy to be deployed and reclaimed, Inductively Coupled Link (ICL) was chosen to realize the wireless communication between the junction box and working tools like samplers. Meanwhile, in order to expand the observatory range of deep seafloor observatory network, Autonomous Underwater Vehicle (AUV) had been incorporated into the system. We used optical communications to realize the high-speed communications between AUV and the deep seafloor observatory network. The main content of this paper is as follows:In order to improve the range of underwater ICL communication, according to the electromagnetic theory and experiments, this paper analyzed various elements of the range of ICL communication, proposed a general method for optimal design for ICL. The communication circuits were redesigned based on the existing system. The amplifier and filter were added and the modulation and demodulation circuits were rectified relatively to improve the range.High-speed optical communication systems were designed, which was one-way information transmission system for LED. It can meet the need of the contactless communication system between AUV and deep seafloor observatory network, high-speed, wide-angle and long range. According to the characteristics of underwater optical communication and optical propagation in water, we chose suitable optical components and electronic components and designed the optical structure, the circuits and the mechanical structure of the optical systems, including the transmitter and the receiver. Finally, the performances of the two communication systems were tested and the technical specifications were measured by the experiments in and out of water. The results showed that the two communications systems had good performance and meet their own requirements well.