Author : Rojgar Qarani Ismael 1
Date of Publication :1st October 2022
Abstract: Combination of Unmanned Aerial Vehicle (UAV) - based aerial imagery and Structure – from – Motion (SfM) photogrammetry become a valuable tool that offers the capability of obtaining high-resolution images for a difficult and inaccessible area to be surveyed. This paper presents results obtained from different methods of georeferencing of UAV imagery using Real-Time Kinematic (RTK), and Post Processing Kinematic (PPK) for generation of Digital Terrain Model (DTM) and Orthomosaic for an area where the elevation difference is about 1100 m. A fixed-wing UAV equipped with a SODA camera were utilized for the corridor mode imagery. The study area were a corridor of (300 m) wide, and 22km length was covered by six flight missions in almost three hours. The Structure from Motion (SfM) technique was applied to create high-resolution 3D-models. The horizontal accuracy obtained from RTK and PPK solutions were (5.2) cm and (6.2) cm respectively; vertical accuracy were (13.2) cm and (14.9) cm for the RTK and PPK methods respectively. This study demonstrated that the RTK – based technique can provide accurate products than PPK method, despite the partially ground coverage by canopies. The results obtained may be considered adequate for mapping, of the area that can be used for other places because many such difficult and inaccessible regions are not yet surveyed in the region.
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