Location deviation correction method based on cross-correlation spectrum in OFDR

Abstract

A location deviation compensation algorithm based on cross-correlation spectrum is proposed for optical frequency domain reflection (OFDR) measurement. The strain and the imperfect repeatability of the laser source may cause a location deviation of the OFDR measurement system, resulting in a demodulation error. This paper proposes to use the peak-to-average ratio (PAR) to measure the quality of the correlation results and achieve compensation, which achieves efficient compensation for location deviation. Compared to other compensation methods, this algorithm can deal with the complex location deviation with better demodulation accuracy and stability. Through a strain measurement experiment, we demonstrate that the demodulation error caused by location deviation is largely eliminated. As a result, the spatial resolution of the system is improved from 8 cm to 2 cm, and the maximum measurement range is expanded to 5000µε.