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Research on ultra long range Φ-OTDR distributed vibration measuring system based on ROPA technology

The ROPA technique has great application prospects for Φ-OTDR relayless engineering applications. This paper realized the 175km vibration sensing distance by using the ROPA and the third-order Raman technology, which can enhance the optical power of the detection signal significantly. At the end of the fiber, a vibration source device PZT is used to ensure the accurate identification of events.