The Performance of Distributed Acoustic Sensing for Tracking the Movement of Road Vehicles

In this paper we introduce Distributed Acoustic Sensing (DAS) and discuss its potential application in Intelligent Transportation Systems (ITS). We present the fundamentals of the technology and data processing methods required for converting the raw data into information that can be used to track the position of vehicles along a road in real time. We present and discuss the results of experiments that explore the dependency of defined DAS signal quality metrics as a function of vehicle speed, size and distance from the fiber, as well as how the cables are installed. The experiments indicate that decisions concerning cable installation could influence data signal to noise by up to ~10 dB. Finally, we demonstrate that DAS systems that operate by measuring phase shifts of laser light backscattered along the fiber, are capable of tracking smaller and slower moving traffic than DAS systems that rely only on measuring the intensity of the backscatter.