Data compression and SNR enhancement with compressive sensing method in phase-sensitive OTDR

An efficient signal processing method based on compressive sensing (CS) is presented for vibration sensing in phase sensitive optical time domain reflectometry system (φ-OTDR), which allows for compressing and denoising the raw data simultaneously. The main information of Rayleigh backscattering curves can be identified by sparse transformation. Then the data is compressed by observation matrix while the unwanted information is discarded. Orthogonal matching pursuit (OMP) algorithm is used to recovery the signal under the sparsity determined by a threshold rule. Experiment results show that the SNR is increased to 34.39 dB with the compression ratio of 18.9 for the vibration event of 100 Hz along 3 km sensing fiber which indicates the prominent performance of the novel method for vibration detection.