Possibilities for Obtaining Terrain Models, Orthophoto Maps, and Point Clouds with the Use of a Multirotor UAV

Abstract

In this paper, a method for acquiring spatial data using unmanned aerial vehicles (UAVs) is presented. In this work, the UAV is a hexacopter equipped with a high-end camera capable of recording 4K video and capturing high-resolution photographs.

The first step in data acquisition involves conducting a flight over the analyzed object, which can be either a land area or a construction site. During the flight, a series of photographs or video footage is recorded. In a later stage, these recordings are processed with the use of appropriate software. This processing consists of several steps. First, the recorded photos are arranged according to their location of capture and then properly stitched together. Based on this, a dense point cloud is created, from which it is possible to build a mesh with an adjustable number of vertices. In addition, the polygons’ textures are extracted from the photographs taken.

According to this approach, it is possible to obtain high-quality data for both terrain and architectural objects. The resulting point cloud can serve as a starting point for performing a variety of analyses or inventories, provide the basis for high-precision models or supplement existing lower-density point clouds.