Contents I. Introduction
Oceanography is entering a new stage in which the research and development activity has been extended from coast to deep-ocean. Therefore, it is desirable to deploy long term underwater observatory with multi sensors to monitor the physical, chemical, geological and biological progress with many spatial and temporal time scales. To gather data from these facilities is a crucial task. Although radio frequencies have enjoyed large success in free space, they experience high attenuation in water and typically not used for underwater communication. Acoustic technology has advantage to transmit data over a long distance in water. However, the attenuation of the acoustic carrier and the effects of multi-path reflection will ultimately limit the data rate and bandwidth for a large amount data communication and even at the short range the bandwidth is limited to sub-Mbps. This brings a “bottleneck” problem for a large amount of data collection (such as multi-sensor data, image information, etc.). Wireless optical communication have shown promise of supporting large bandwidths, high data transfer rate, small in size, low power consumption, immune to electromagnetic interference. Thus, underwater wireless optical communication can be an alternative method for fast data transmission. By incorporating optical wireless system into autonomous underwater vehicle (AUV), we can make use of AUV to approach to the location of seabed observatories or mooring systems to gather logged data and then to transport the data package to research ships within short range. It provides an alternative solution for real time data passing and monitoring mission coordination wirelessly with free swimming underwater vehicle in a expand distance.
