Abstract
The Digital Elevation Models (DEMs) are essential source of topographic information in many disciplines. The goal of this research was to exploit leaf-off UAV images as an alternative method for DTM development in a dense forest. In this regard, the low-altitude images acquired by a consumer-grade camera mounted on a drone was used for analysis. For DTM generation we used a photogrammetry-based workflow to produce and classify 3D point clouds. Based on ground 3D point clouds and interpolation technique a high resolution DTM was generated. The results indicated that, there is a strong relationship between the estimated (leaf-off UAV images) and measured (DGPS) Z values (R2 = 0.972 and RMSE = 1.47 m). We concluded that the VHR leaf-off UAV aerial imagery can be used for DTM extraction from dense forests.