Comparison of unmanned aerial vehicle RTK/PPK methods in monitoring the quarry surface change

Abstract

Quarries are enterprises where mining activities are carried out by using the open pit mining method of stones and similar minerals. The use of remote sensing techniques makes it indispensable in such cases due to the difficulties in measuring with terrestrial measurement techniques in areas where the topography is rough and difficult to reach. Real-time kinematics (RTK) technique provides the satellite-based position accuracy from the nearest base stations and gives the sensitivity of the position data obtained with cm sensitivity. However, Post Process Kinematic (PPK) measurement technique provides an alternative solution in regions whose topographic structure is not suitable for satellite-based positioning. The aim of this study is to evaluate the accuracy of the RTK and post-measurement data evaluation (PPK) solution through post-processed and corrected measurements by Global Navigation Satellite Systems (GNSS) and RTK-CORS. A special quarry within the boundaries of Düzce/Tatlıdere Forestry Operations Directorate was chosen as the study area. Using the DJI Phantom-4 RTK unmanned aerial vehicle (UAV), which has RTK and PPK application modules, two simultaneous flights in RTK and PPK modes were carried out in the quarry. The average position accuracies determined on the orthophoto by RTK and PPK method were obtained as 2,405 cm and 0.813 cm, respectively. According to these results; PPK solution has emerged as more accurate in areas with high height difference such as the quarry area. In addition, the PPK method gave more accurate results than the RTK method in determining the quarry slope step width.