Patent ID: 7800743

Claim:
A method of identifying a zone of non-threatening disturbances along a buried optical fiber comprising: inputting a light into a first end of the buried optical fiber; receiving a first optical signal from the first end of the buried optical fiber created by a first low frequency ground vibration received by the buried optical fiber; identifying the location along the buried optical fiber where the first low frequency ground vibration was received; analyzing the received first optical signal using an approximation algorithm comprising: adding environmental condition variables to the received first optical signal forming a conditioned first optical signal; comparing the conditioned first optical signal with a set of prearranged optical signals, the prearranged optical signals corresponding to predefined low frequency ground vibration patterns; if the comparison determines that the conditioned first optical signal matches one prearranged optical signal from the set of prearranged optical signals, identifying the first low frequency ground vibration location as a non-threatening disturbance; and if the comparison determines that the conditioned first optical signal does not match one prearranged optical signal from the set of prearranged optical signals, identifying the first low frequency ground vibration location as a threatening disturbance.