This EAGER proposal seeks funding to extend the Sensorbot network design, range and coverage by incorporating multi-hop functionality. Sensorbot developed by the PIs with internal ASU funding is a miniaturized, low-cost, underwater, autonomous sensor platform. A single Sensorbot constitutes a network node, capable of measuring and reporting the properties of the fluid in which it is located. With EAGER funding, short-range communicating Sensorbots will be intelligently link together to extend their coverage over long distances in a multi-hop networking approach, thus overcoming the range limitation of standard underwater optical communication.
If successful, once deployed, the network of Sensorbots is expected to not only achieve continuous, autonomous, long term monitoring campaigns but to sustain two-way communication within the network. The goal of this project is to significantly extend the spatial range and coverage of a network of optically-communicating, deep ocean sensors.
The Sensorbots were created to measure a wide range of low-temperature hydrothermal fluid properties. Sensors for pH, dissolved oxygen, trace metals, and temperature are now in operation, and several others are in the early stages of development. Currently under development are fluorescent polymers that respond to methane, sulfate, CO2, and other critical analytes in areas of diffuse flow in hydrothermal regions of the deep ocean. With improved communications, optical multi-hop networked Sensorbots will have broad and immediate application to a diverse array of ocean sensing fields. This potentially transformative proposal is expected to yield solutions to previously intractable questions about the extent of biogeochemical flux on the ocean floor. This project will include one post doc and two undergraduate students.
Unlike underwater acoustic communication technology, underwater optical communication technology is poised to carry wireless video data and support very large numbers (potentially many thousands) of nodes in high-density networks. The challenge is that light is highly attenuated by seawater and has a limited point-to-point range. By introducing multi-hop capability, sensor nodes are able to transfer data to adjacent nodes and throughout the entire network, thus overcoming the otherwise inherent range limitation of underwater optical communication. Multi-hop optical networks open up possibilities for ocean sensor deployments. Underwater sensor networks employ a spatially distributed array of communicating nodes, in which each node collects or transmits data that is temporally and geographically referenced to a broader context. Having an accurate understanding of the position and time of each network node is required to correlate measurement data within the network and with other available data sets when integrated as part of a broader observatory. Dense underwater optical networks are expected to achieve continuous, autonomous, long term monitoring campaigns, to geospatially localize, and to sustain high-speed two-way communication over areas of critical interest. Underwater optical networks have high-bandwidth applications in science, security, and industry in the areas of environmental monitoring, accident remediation, defense surveillance, oil and gas industries, aquaculture, geological and oceanographic science, and marine biology.