Use of unmanned aerial vehicles in highway projects in rugged areas

Today, using unmanned aerial vehicles (UAVs) has become pretty widespread in engineering applications with software and hardware components that have been developed. Some photogrammetric problems have been eliminated due to the use of high resolution and different camera types by the UAVs that provide flight at different heights and speeds. With these developments, it is possible to produce DTM with high accuracy with the UAV technique. This study has been carried out to investigate the usability of unmanned aerial vehicles in highway projects in rugged areas. In this direction, the data obtained by the ground method and UAV have been compared in terms of volume quantities and elevation information. As a working area, a rugged highway corridor of about 800 meters in length and 300 meters in width has been chosen. Images have been taken by performing 4 flights at different heights and different overlay rates with an unmanned aerial vehicle. The coordinates of ground control points and terrain detail points have been determined by the classical RTK method using the GNSS device. The images have been processed with a different number of ground control points (GCP) in the Pix4D and Agisoft PhotoScan software and the digital terrain models (DTM) have been produced. Error amounts of ground control points and control points, the location of ground points produced by ground measurement technique and UAV method and calculated volume amounts have been compared. As a result, the difference in volume amount has been maximum 3.5% and the minimum has been 0.6%, and the differences between the heights of the points have been obtained with the lowest 12.9 cm in the Pix4D software and the lowest with agisoft Photoscan software at 15.9 cm.