METHODS FOR GENERATING THE DIGITAL TERRAIN MODEL, DIGITAL SURFACE MODEL AND ORTHOMOSAIC USING UAV AND GNSS TECHNOLOGY PUBLISHEDBianca GHERGA1, Ovidiu TIMBOTA, Radu BERTICI, George POPESCU, Mihai Valentin HERBEI None firstname.lastname@example.org
The purpose of this article is to accomplish a Digital Terrain Model, Digital Surface Model and an orthophotoplan - orthomosaic of an area within the Didactic and Experimental Resort of BUASVM Timisoara based on geomatic technologies. The interest for UAVs has been constantly growing, researchers and developers use a lot of resources and efforts to contribute to this topic, especially in applications of geomatics in various fields such as: agricultural and forestry, autonomous surveillance (Herbei and Sala, 2020), emergency and disaster management, traffic management and 3D mapping with photogrammetry. This increase is mainly due to the fact that UAV systems are a reliable and low-cost alternative, fast speed, high maneuverability and high security for image collection. A DJI Phantom 4 drone was used in this work. Phantom IV is a system composed of a drone (UAV) and a mobile RTK station and is suitable for aerial photography and aerial filming activities suitable for data processing in order to obtain orthophotoplanes, point clouds or 3D modeling. Most drones have built-in GPS, IMU (inertial measurement unit) and barometric altimeter, to help navigation. The default positional accuracy is generally good enough for many GIS applications. For example, the DJI Phantom 3 Pro has a position accuracy of ± 1m. If necessary, you can improve position accuracy using ground control points (GCPs), see Ground control points. Ground control points (GCPs) are used in image processing to improve the positional accuracy of data. GCPs are physical locations marked with a fixed position, the coordinates of which have been accurately determined (for example, using a combination of navigation systems, such as GPS and GLONASS, or by using differential GPS). In order to purchase images from the field with UAV technology, the Pix4D application and a mobile tool with Android OS were used, which allowed the realization of the flight plan to acquire the images from the desired location.
UAV, DJI Phantom, Pix4D, DTM, DSM