Patent ID: 8345229

Claim:
A long-distance monitoring system comprising: a first optical fiber; a sensing unit comprising: a first source of optical energy configured to inject optical energy into the first optical fiber; and a first optical detector configured to detect a first optical return signal from the first optical fiber, the first optical return signal associated with an acoustic signal impinging on the first optical fiber; an analyzer remote from the sensing unit and configured to receive a first signal via the first optical fiber representative of the first optical return signal from the remote sensing unit and determine a location of a disturbance based on the first signal using a multi-dimensional layout, wherein the analyzer determines the location of the disturbance using the acoustic signal, wherein if a source of the disturbance moves, the location of the disturbance is determined at various times, and wherein the optical energy injected into the first optical fiber has a wavelength that is different from a wavelength of the first signal; a communication unit configured to transmit one of: the first signal over the first optical fiber at the wavelength of the first optical fiber that is different from the wavelength of the first signal to the analyzer; and the first signal over a first metallic wire of the first optical fiber to the analyzer; a power source remote from the sensing unit and configured to provide power over a second metallic wire; and a power subsystem configured to receive the power via the second metallic wire.