The RFID Markers Localization Accuracy for Marking the Position of Non-Metallic Underground Pipes and Cables in Smart Cities

Non-metallic underground infrastructure localization, including optical fiber cables and plastic pipelines, is one of the most challenging tasks in Smart City development due to the comprehensive monitoring and management of utilities that requires precise mapping capabilities. In this work, we have investigated the accuracy and reliability of three commercially available RFID marker types—circular, ball, and PIN—for non-metallic underground pipeline localization through systematic laboratory tests. We investigate how marker inclination in the range from 0° to 70° affects the localization error measured at a distance of 1.0 and 1.5 meters from the pipe. A mathematical model of the observed phenomena is developed. It has been found that: i) circular markers are characterized by high sensitivity to inclination; indeed, for 70° inclination, the localization error achieves the value of 59 cm. The ball markers with orthogonal coils are angle-independent; however, the maximum detectable distance is only 1 meter, whereas iii) PIN markers reveal moderate sensitivity: beyond 60° inclination, the signal is totally lost. When installed properly, that is, when their inclination is 0°, all of the above markers provide localization accuracy of approximately ±10 cm, which largely outperforms the standard low-cost GNSS systems. In this work, essential implementation guidelines for Smart City underground infrastructure are derived, pointing out proper selection of a marker and installation methodology in order to ensure reliable non-metallic pipe localization.