Optical frequency domain distributed optical fiber sensing method based on Rayleigh scattering spectrum local similarity

The invention discloses an optical frequency domain distributed optical fiber sensing method based on Rayleigh scattering spectrum local similarity, and belongs to the technical field of distributed optical fiber sensing. According to the method, traditional optical frequency domain distributed optical fiber sensing data are processed by utilizing Rayleigh scattering spectrum local similarity and three similarity evaluation functions, and the problem of deterioration of reference and measurement spectrum similarity under wide-range sensing is solved. According to the invention, on the premise that the structure and the sweep frequency range of the optical frequency domain distributed optical fiber sensing system are not changed, the strain or temperature measurement range of the OFDR is improved only through the algorithm of matching the local reference spectrum with the measurement spectrum; moreover, the signal-to-noise ratio of cross-correlation operation can be greatly improved, and the accuracy of accura