Location and monitoring of undersea cables
AssigneeOptasense Holdings Limited
InventorMagnus McEwen-King
Life of this patent
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Abstract
The present application described methods an apparatus for locating and/or monitoring subsea cables (101) having an optical fibre (105) deployed along its length. The optical fibre (105) is connected to a distributed acoustic sensing (DAS) interrogator unit to interrogate the optical fibre to provide a fibre optic DAS sensor. To locate the cable an acoustic stimulus is transmitted into the water from one or more known locations. The time of arrival of an acoustic signal matching the stimulus at the sensing portions of the DAS fibre can be detected and used to determine information about the location of those sensing portions to the known location. The DAS signals returns can also be monitored under ambient conditions to detect any signals indicative of likely damage to the cable.
Claims21
A method of locating a cable deployed within a body of water comprising:
- interrogating a first optical fibre deployed along the length of said cable to provide a distributed acoustic sensor comprising a plurality of longitudinal sensing portions of fibre;
- transmitting an acoustic stimulus into the body of water from a plurality of different known locations, and
- processing the returns from the distributed acoustic sensor from the plurality of longitudinal sensing portions of fibre to determine the location of the fibre by determining the relative time of arrival of the acoustic stimulus at the various sensing portions of the optical fibre.
Dependencies are inferred from the claim text.