Ultra-Low-ZCPs Long-Distance OFDR Based on Compressive Sensing Technology

To achieve long-distance optical frequency domain reflectometry (OFDR) sensing, high zero crossing points (ZCPs) are typically needed to satisfy the Nyquist sampling theorem. However, these high ZCPs impose a substantial burden on data acquisition. In this study, we propose an OFDR scheme based on compressed sensing (CS) technology, which enables long-distance sensing with ultralow ZCPs. The proposed scheme employs a dual external clock nonuniform sampling method combined with the orthogonal matching pursuit (OMP) algorithm, allowing signal reconstruction under undersampling conditions. The experimental results demonstrate that the scheme achieves a sensing distance of 200 meters, and each sampling channel has ZCPs below 106. Compared to existing OFDR schemes with sensing distances on the order of hundreds of meters, our approach reduces ZCPs by an order of magnitude.