An acoustically controlled tetherless underwater vehicle for installation and maintenance of neutrino detectors in the deep ocean

Abstract

TECHNICALABSTRACT (Limittospace provided. Applicants MUST usetheformat provided intheinstructions onthereverseside.1 The task ofinstalling and servicing high energy neutrino detectors inthe deep ocean froma surface support vessel is problematic using conventional tethered systems.)narray ofmultiple detector strings rising 500 m from the ocean floor, and forming a grid with 50 m spacing between the strings, presents a substantial entanglement hazard for equipment cables deployed from the surface. Such tasks may be accomplished with fewer risks using a tetherless undenvater remotely operated vehicle that has a local acoustic telemetry link to send control commands and sensor. data between the vehicle and a stationary hydrophore suspended above or just outside the-. perimeter of the work site. The Phase I effort involves the development of an underwater acoustic telemetry link for vehicle control and sensor feedback, the evaluation of vidto compression methods for real-time acoustic transmission of video through the water. and the defining of local control routines on board the vehicle to allow it to perform certain basic maneuvering tasks autonomously, or to initiate a self-rescue if the acoustic control link should be lost. In Phase H, a prototype tetherless vehicle system will be designed and constructed to demonstrate the ability to install cable interconnections within a detector array at 4 km depth. The same control technology could be used with a larger more powerful vehicle to maneuver the detector strings into desired positions as they are being lowered to the ocean floor. COMMERCIAL APPLICATIONS AND OTHER BENEFITS as described by the applicant. (Limit to space provided). A tetherless ROV offers a tremendous commercial advantage over tethered systems. Elimination of the umbilical cable, with its intrinsic drag and entanglement hazards, allows much smaller. lower-powered, and less expensive vehicles to be used at greater speeds and longer excursion distances from the deployment vessel. Possible applications include mapping of the ocean floor. search and recovery operations, military mine countermeasures, and fisheries research. " KEY WORDS: tetherless umbilical cable unmanned untethered UUV remotely operated vehicle ROV neutrino deep ocean acoustic telemetry video compression 19 .