Research Of Testing Data On Optical Time Domain Reflector

In this paper, for the first time the modulus maximum pair of wavelet transform was used to detect OTDR signals by detecting their singularity points. OTDR signals were decomposed with a dyadic spline wavelet by Mallat algorithm, all kinds of event points were recognized by analyzing the relationship between signal with points of event and the modulus maximum pairs of its wavelet transform.Besed on wavelet' s well localized characterizes in time frequency and space frequency, we can exactly depict events of nonnoise by decomposing to signal using binary-wavelet transform . For events of noise , local max can be found at singular points of signal by using wavelet transform norm of signal, so adopting multiscale wavelet analysis the maximal point of wavelet transform norm, which risen by the noise ,with increasing of scale, which rien by the fault appeared. Gived a properly threshold and compared the relation of data that have been transformed not only find the fault in the low noise signal but also resume the signal by filtering noise, which have good power of examining singular signal being unexpectedly change. So we can efficient find the events in the noise. In chapter 3 we analysis and compute to different events.The wavelet tansform' method in this paper is able to automatically and accurately orient to fault points of fiber and provide evidence for automatic analysising to data from inspecting fiber. In view of influence of noise, the choice of threshold will be another question for us.