Deep-Sea Fiber Optic Distributed Temperature Sensing

December 8, 2022
Deep-sea fiber optic distributed temperature sensing system deployed at 2000m depth in the Western Pacific Ocean in close proximity to a hydrothermal vent. Image credit: Roxanne Beinart

PI: Brennan Phillips, Undersea Robotics and Imaging Laboratory

Funding Sources: ONR, NIUVT

SUMMARY: Fiber optic distributed sensing (DS) is at the frontier of several ocean sensing applications, from both a distributed acoustic sensing (DAS) and distributed temperature sensing (DTS) perspective.  DS allows for high resolution spatiotemporal sensing over a continuous length of fiber optic that can be interrogated synoptically, over distances of kilometers, with a single interrogator/receiver being used at one end.  While still an emerging technology, DS can offer truly elegant sensing solutions for water column arrays, seafloor arrays, and towed cables for both DAS and DTS.  The Undersea Robotics and Imaging Laboratory (URIL) at URI has developed the world’s first deep-sea DTS units, which can operate up to 6000m deep as either standalone sensing units or as part of a larger observatory array.  These units are currently being deployed for water-column DTS sensing as well as seafloor hydrothermal vent sensing.