Method and apparatus for acoustic sensing using multiple optical pulses
AssigneeAT&T Intellectual Property II, L.P.
InventorsJustin Hayward, Andrew B. Lewis, Stuart Russell
Life of this patent
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Abstract
An improved technique for acoustic sensing involves, in one embodiment, launching into a medium, a plurality of groups of pulse-modulated electromagnetic-waves. The frequency of electromagnetic waves in a pulse within a group differs from the frequency of the electromagnetic waves in another pulse within the group. The energy scattered by the medium is detected and, in one embodiment, may be used to determine a characteristic of the environment of the medium. For example, if the medium is a buried optical fiber into which light pulses have been launched in accordance with the invention, the presence of acoustic waves within the region of the buried fiber can be detected.
Claims20
A method comprising:
- detecting, using a system comprising a processor, a first signal in a medium;
- determining, from the first signal using the system, a plurality of complex signals, each of the plurality of complex signals corresponding to one of a plurality of fixed locations along the medium;
- extracting, using the system, phase information from each of the plurality of complex signals;
- and
- for each respective fixed location, combining, using the system, the phase information of the complex signals associated with the respective fixed location to detect a disturbance in the medium.
A system comprising:
- a plurality of detectors for detecting a first signal in a medium;
- a demodulator for determining, from the first signal, a plurality of complex signals, each of the plurality of complex signals corresponding to one of a plurality of fixed locations along the medium;
- a processor;
- and
- a memory to store computer program instructions, the computer program instructions when executed on the processor cause the processor to perform operations comprising:
- extracting phase information from each of the plurality of complex signals;
- and
- for each respective fixed location, combining the phase information of the complex signals associated with the respective fixed location to detect a disturbance in the medium.
A computer readable medium storing computer program instructions, which, when executed on a processor, cause the processor to perform operations comprising:
- detecting a first signal in a medium;
- determining, from the first signal, a plurality of complex signals, each of the plurality of complex signals corresponding to one of a plurality of fixed locations along the medium;
- extracting phase information from each of the plurality of complex signals;
- and
- for each respective fixed location, combining the phase information of the complex signals associated with the respective fixed location to detect a disturbance in the medium.
Dependencies are inferred from the claim text.