The surface modelling based on UAV Photogrammetry and qualitative estimation

Recently, the interest in Unmanned Aerial Vehicle (UAV) application in photogrammetric environment has increased in many countries. The fixed-wing UAV, the model of EPP-FPV with mounted digital camera Canon S100 was used as a platform for images acquisition. Implemented means are low-cost, mobile and simple. Digital photogrammetry technology with Pix4D software application has been applied for UAV images processing and area mapping. High quality of images is a significant factor for the efficiency and accuracy generating standard mapping products. The correctness of digital surface models and orthophotos mainly depend on camera resolution, flight height and ground control point (GCP) accuracy. The paper reports on investigations how number of GCPs used for UAV image transformation influences the mapping results. The demand of such investigations arises because the flight paths with a fixed wing UAV have general form, in contrast to classical paths which are pricewise straight lines, as well as the flight significantly depends on weather conditions (especially on wind) and the platform shows considerable tilt because of its light weight. The results of DSM accuracy investigation demonstrate the quality of UAV Photogrammetry product with the use of appropriate number of GCPs.