Road Signs Detection and Evaluation of Distance Measurement Errors Observed in MMS Point Clouds Equipped with Phase-Shift Laser Scanners

Abstract

In a mobile mapping system equipped with a phase-shift laser scanner, the point cloud data of road signs appear behind their actual positions. This phenomenon refers to ‘Nonius jump’ by the manufacturer while it is attributed to the retroreflective materials. However, effective research has not been found regarding preventions for the “Nonius Jump” phenomenon. On the other hand, detection of distance measurement errors is performed visually, which requires significant labor. In this study, we propose a method of detecting road signs and evaluating distance measurement errors based on the standard deviation of the relative distance between road sign and the mobile mapping system. The results confirm that the standard deviation of the relative distance can be used to detect road signs with distance measurement errors.