Real-Time Vehicle Traffic Detection Using Distributed Fiber Optic Sensors

Abstract. We present a real-time, fully automatic vehicle traffic mon- itoring system based on phase-sensitive Optical Time Domain Reflec- tometry (Φ-OTDR) using distributed fiber optic sensors. The solution is designed for embedded on-the-edge deployment, leveraging a com- pact system composed of an FPGA with an integrated processor. It enables direct, in-stream processing of Φ-OTDR signals without requir- ing data storage or offline analysis. The system emulates, among oth- ers facilities, the functionality of a simplified Hough Transform (HT) through a lightweight hardware architecture based on an array of binary shift registers, optimized for detecting near-vertical line segments that correspond to the signature of moving vehicles. The proposed solution demonstrates that existing optical fiber networks can be effectively repur- posed for low-power, real-time traffic monitoring using dedicated embed- ded hardware.