Wireless data harvesting using the AUV Sentry and WHOI optical modem

The optical communications group at Woods Hole Oceanographic Institution has demonstrated wireless optical transmission of data from a seafloor node to the Sentry AUV. This effort is based on the latest version of the optical modem under continual development at WHOI, and it builds on fieldwork conducted in 2012 and 2013 during which we successfully transferred data from seafloor-deployed optical modem systems using a wire-lowered optical modem from a ship. While our previous work used a high-bandwidth optical modem for the data uplink and an acoustic modem “backlink” to control the file transfer, the optical modem described in this paper supports fully bidirectional optical communication-essentially subsea WiFi. A subordinate objective of our work was to literally map the operational space for an AUV-bottom node optical link. Armed with this spatial map, we can plan for future “connected” AUV operations in support of data mule, inspection, manipulation, and other underwater semi-autonomous tasks.