Comparative Analysis of RTK and Net-RTK Accuracy in UAV-Based Photogrammetry

Abstract

This study evaluates the positional accuracy of UAV photogrammetry using RTK and Networkbased RTK (Net-RTK) methods. A two-story building was selected as the test site, and photogrammetric flights were conducted with consistent flight parameters for both RTK and Net-RTK systems. The 3D coordinates of characteristic points on the structure were digitized for both methods, with RTK-based data serving as the reference for comparison. Root Mean Square Error (RMSE) values were calculated to assess the accuracy, indicating minor random discrepancies in horizontal coordinates (Y and X) but a more notable and possible systematic error in the vertical component (H). Statistical analysis confirmed that while Y and X axis differences were random, height differences displayed a systematic trend, particularly evident in Net-RTK measurements. The results suggest that while RTK offers higher vertical accuracy suitable for precision applications, Net-RTK remains a viable alternative for general purposes, particularly in areas with reliable internet connectivity.