Analysis and Comparison of Lines Obtained from GNSS and UAV for Large-Scale Maps

Abstract

Nowadays, obtaining large-scale topographic maps from unmanned aerial vehicle (UAV) photogrammetric projects has become an alternative to traditional surveys based on global positioning systems (GPSs) or total stations. This assumption is based on the reduction of costs, the application to reduced zones, the efficiency of the procedures, and the positional accuracy achieved, etc. In this context, this study analyzes and compares the lines obtained from two sources: a global navigation satellite system–real-time kinematic (GNSS-RTK) survey and an UAV photogrammetric project. Usually, the GNSS data set of lines has a higher positional accuracy, whereas the UAV data set has a richer geometry. The proposed methodology realizes several positional controls (based on lines) to analyze the positional accuracy of the UAV data set of lines and the geometrical representability of the GNSS data set of lines. In addition, an improvement in the representation of lines with poor geometry is suggested by using a hybrid model composed of splines and straight segments. The application is implemented using more than 11 km of lines obtained from both sources. The results confirm the viability of the positional control based on lines, the sufficient accuracy of lines obtained from the UAV to be used for maps at large scales, and the improvement in the representability of the proposed hybrid model.