Runways ground monitoring system by phase-sensitive optical-fiber OTDR

Abstract

Runways monitoring in civil airports is typically performed by enhanced radar surveillance systems operating in the so-called Precision Runway Monitor (PRM) system that provides position of airplanes and information on their trajectories. In this paper, we propose an additional measurement system that can be used jointly with the conventional PRM approach to monitor aircrafts position on land without using the radar approach or requiring visual inspection of the lanes. We propose a system made of ground-based distributed optical fiber sensors (OFSs), to be placed below the concrete floor of the take-off and landing lanes as well as along the different roads and intersections within the airport. OFSs will be read by a phase-sensitive OTDR (Φ-OTDR) driven by low-noise narrow-linewidth 1.55 mm laser. The laser field is used to inject the optical fiber with a pulsed signal and to read the phase shifts arising from vibrations and pressure waves produced by aircrafts moving, or even still with engines turned on, along the lanes. An absolute localization of different planes, with a few meters resolution and accuracy across the whole airport, would be possible after installing OFSs and adjustment of the detection system. The proposed ground monitoring system, in addition to the ones currently available, offers information redundancy at a promising low-cost and a backup aircraft-positioning tool in case of failure or malfunctioning of the existing video-or radio-based systems. Furthermore, the proposed system is inherently immune to e.m. interference and also to intentional disturbance or intrusion. Design of the laser source and of the Φ-OTDR measurement system is underway with the aim of precise and continuous monitoring of the on-land position and movement of different aircrafts or vehicles within the airport.