We report a novel method of event discrimination using phase correlation in Φ-OTDR system based on coherent detection. The phase change demodulated from the Rayleigh backscattering light is the result ...

We demonstrate a $300-\\mathrm{km}$ unrepeatered $\\Phi$-OTDR with 1 -meter-high spatial resolution, achieving a record of 300000 effective sensing points through fractional Fourier transform for ...