Deployment and maintenance of scientific sensors in the oceans is costly. This has created momentum for the idea of using already installed fiber optical connections to obtain scientific data. In the EU backed SUBMERSE project (SUBMarine cablEs for ReSearch and Exploration), 24 partners are building proof-of-concept. Norwegian universities NTNU and University of Bergen are leading partners, supported by NORDUnet, Norwegian NREN Sikt, and Danish NREN DeiC.
The project was initiated in 2023 and currently has three data collection sites – in Norway, Greece, and Portugal.
One technique used is distributed acoustic sensing (DAS), which is reminiscent of a one-dimensional radar. An optical pulse is launched into the end of the fiber, and the backscattering taking place at different points through the fiber is measured. Movement of marine animals or ships in the vicinity will make the cable vibrate as will seismically noise. These vibrations translate into strain in the fiber which can be detected.
Another relevant technique is state of polarization (SOP) which is especially effective for detecting ships near submarine cables due to its sensitivity to changes in polarization caused by nearby mechanical vibrations.
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Submitted by Morten Anderson
