UAV Application in Creating 1:2000 Topographic Maps for Wind Power Projects in Ha Tinh Province, Vietnam

Abstract

In the survey area (high coverage density and 1km height difference between the foot and the top of the mountain), the UAV with LiDAR sensor is used. From the assigned coordinates and altitude, GNSS RTK technology is used to establish ground control points (GCPs). From these GCPs and terrain conditions, 29 aerial photography subdivisions are designed for the project. The flight route design is carried out on the principle of covering the entire flight area, ensuring the highest accuracy. Based on the subdivision boundaries, ground resolution of the image, vertical coverage and horizontal coverage of the image, flight direction, camera photography parameters, and technical specifications of the UAV device, proceed. Determine flight altitudes and specific flight routes for each flight subzone. GCP Ground Control Point and CP Check Point (Check Point) are used. Check the vertical coverage and horizontal coverage of the photo compared to the design; then proceed to link and correct the image blocks. When the image block correction results meet the requirements, proceed to create a dense point cloud from the image volume results that have been adjusted to a size not smaller than the resolution of the original image. Use point cloud data to create a DEM model. The RMS error in horizontal is 10.4 (cm) and vertical is 1.3 (cm) confirming enough reliability to create a 1:2000 scale topographic map.