Evaluating the performance of GNSS RTK and UAV (drone) technologies under vrs mode in challenging environments

Abstract

The advancement of modern geospatial technologies has significantly improved the efficiency and accuracy of engineering surveying through the integration of Global Navigation Satellite System Real-Time Kinematic (GNSS RTK), Unmanned Aerial Vehicle Real-Time Kinematic (UAV RTK), and Simultaneous Localization and Mapping Real-Time Kinematic (SLAM RTK) systems. However, their performance under challenging environmental conditions remains a critical concern due to signal obstruction, canopy interference, multipath effects, and operational limitations. This study evaluates and compares the performance of GNSS RTK, UAV RTK, and SLAM RTK technologies operating under Virtual Reference Station (VRS) mode across urban, forested, mixed-use, and semi-urban environments. Field surveys were conducted using a TOKNAV T5Lite GNSS RTK receiver, static GNSS observations, Total Station traverse surveys, a DJI Matrice 350 RTK UAV equipped with a Zenmuse L2 LiDAR sensor, and a GoSLAM M40 handheld mobile mapping system. Positional accuracy was assessed through coordinate comparison and Root Mean Square Error (RMSE) analysis using adjusted reference coordinates established from the control network. GNSS RTK achieved the highest positional accuracy, recording horizontal RMSE values of 0.064 m, 0.079 m, 0.074 m, and 0.121 m in urban, forested, mixed-use, and semi-urban environments, respectively. UAV RTK recorded an RMSE of 0.106 m in urban areas, while SLAM RTK recorded RMSE values of 0.160 m and 0.299 m in forested and mixed-use environments. The findings demonstrate that GNSS RTK provides the highest positioning accuracy under favorable satellite visibility conditions, whereas UAV RTK and SLAM RTK offer significant operational advantages for rapid mapping and surveying within large-scale or obstructed environments.