Collaborative Research: Development of an Autonomous Ocean Observatory Node

The demand for observing the ocean beyond the coastlines has led to numerous installations of sub-sea cabled observatories in the last two decades. However, many scientifically-interesting places are too far from shore, thus, are difficult for cables to reach. The vastness of the oceans calls for new technologies to enable similar infrastructure to sense deeper oceans and enhance scientific investigations in seismology, geodesy, ocean chemistry, marine biology, etc. Recently, autonomous underwater vehicles (AUVs), gliders, and seafloor robots and sensors have been utilized to observe and understand these remote ocean regions. However, the lack of supporting infrastructures for these robots and sensor networks has been the bottleneck for sustainable development. Ultimately a versatile and highly capable Autonomous Observatory Node (AON) for the deep ocean is desired to provide power recharging, data communication, and Position, Navigation, and Time (PNT) services to deep sea sensor networks and AUVs. In this project, the investigators will design and prototype a first-phase AON consisting of two subsystems: the underwater acoustic communication subsystem and the Underwater MicroGrid (UMG) subsystem. The acoustic subsystem uses a large number of transducers to receive data from seafloor sensors and AUVs and transfer their data to a surface glider which then relays the data to the Internet. The acoustic subsystem will explore the underwater Multiple-Input-Multiple-Output (MIMO) technology to provide simultaneous communication and PNT services. The UMG subsystem takes a variety of power sources as input and converts them into electrical power to support both continuous, low-power sensor loads and brief, high-current demanding loads with the acoustic subsystem. Both subsystems will take the Pressure Tolerant Electronic (PTE) approach to design their critical components for enhanced power efficiency and pressure tolerance. The prototypes will be pressure tested at 10,000 psi and ocean tested at 500 m depth. The prototype AON will be first applied to deep ocean sensing and earthquake early detection systems. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.