Data Acquisition Tree Height and Areal Parameters of Mangrove Vegetation Using UAV

Abstract

Unmanned aerial vehicles (UAVs) can be used to assess the biophysical parameters of mangroves (particularly tree height and area). UAVs can produce high-resolution imagery, in this study UAV imagery was used to calculate tree height distribution and mangrove area. UAV imagery was taken using a commercial UAV with a planned flight path. The obtained UAV images are then compiled based on coordinate information and z-elevation values, and then 3D modelling is created from the point cloud. The 3D model will be detailed by a dense point cloud. The surface area and texture are obtained from the 3D mesh. Finally, a high-resolution DSM can be generated. DSM is the elevation of the overall surface including vegetation, buildings, and others, while DTM is the elevation data of the ground surface, so the next process is to separate bare ground and above-ground objects. Tree height is obtained from the intersection of DSM and DTM elevation data. The area of mangrove vegetation was obtained using the on-screen digitisation method. Based on the results of the analysis conducted by comparing tree height data from UAV images and in-situ measurement tree height data has a difference with a range of 0.24 m to 0.94 m, with an average of 0.49m. This remote sensing survey research using commercial UAVs can be concluded as one of the solutions to acquire the parameters of tree area and height distribution with good accuracy.