Strain resolution enhancement in Rayleigh-OTDR based DSS system using LWT-MPSO scheme

This paper presents a scheme for performance improvement of a Rayleigh-optical time domain reflectometry (OTDR) based distributed strain sensing (DSS) system using the combined effect of lifting wavelet transform (LWT) and modified particle swarm optimization (MPSO) method. In our proposed scheme, MPSO evolutionary algorithm produces an optimum threshold and helps in minimizing the noisy lifting wavelet coefficients effectively. This allows an order-of-magnitude increase in strain resolution of the proposed system. The proposed sensing system is capable of measurement up to 50 km using a 10 mW of input laser source power. We have applied 30 με strain at 30 km position of the fiber under test. The proposed signal processing scheme offers better performance over a conventional system. The system achieved a strain resolution of ∼ 1.8 με. Relevant numerical simulations are presented using MATLAB 15.0.