Browsing by Author "Abufana, Saleh"
Now showing 1 - 1 of 1
Results Per Page
Sort Options
Item PERFORMANCE ANALYSIS OF SIGNAL DE-NOISING TECHNIQUES IN DISTRIBUTED ACOUSTIC SENSING SYSTEMS(2022-01-21) Abufana, Saleh; Kara, AliIn this thesis, it is aimed to propose a novel method to detect and classify the threats for fiber optic distributed acoustic sensing (DAS) systems based on phase OTDR. In the first stage of the proposed method, Wavelet de-noising method is applied to remove the noise from the measured backscattered signal, and difference in time domain approach is used to perform high-pass filtering. In this stage, autocorrelation is also used for improving interferometric visibility of the events in all range bins. Further, the power of the correlated signals at each bin is calculated and sorted. Hence, the maximum valued bins are considered to be the event signal. In the second stage, the detected event signals are decomposed into a series of band-limited modes by using VMD technique, and from these modes, the enhanced event signals are reconstructed. Moreover, from the reconstructed event signals, higher order statistical (HOS) features are extracted. In the last stage, Linear Support Vector Machine (LSVM)-based classification approach is implemented to the extracted features for discriminating the threats. In order to measure the effects of the proposed method on the classification performance, different types of activities collected from various points of a fiber optic cable have been used under different SNR levels. The results show the effectiveness of the proposed method in threat detection and classification.