This invention relates to the field of
optical fiber communication testing technology, specifically a method for distinguishing adjacent fault points and estimating the distance between them using an OTDR. The method first acquires the OTDR backscattering curve of the
optical fiber link under test, and then locates the starting position of the first fault point through preprocessing. Within a local analysis window, single-fault and double-fault physical models considering the
system's finite pulse width and bandwidth characteristics are established. After baseline removal
processing of the local observation
signal, the optimal parameters of the two models are estimated using ordinary
least squares and variable projection methods, respectively. Then,
model selection is performed based on the
Bayesian information criterion to determine the number of fault points, and when a
double fault is identified, the estimated distance between the two fault points is output. This invention solves the problem of accurately distinguishing the number and estimating the distance between adjacent fault points when their responses overlap, significantly improving the OTDR's ability to distinguish and locate nearby fault points. It has high computational efficiency, good robustness, and is suitable for long-distance,
large dynamic range optical fiber link testing scenarios.