COMPARATIVE ANALYSIS OF RGB AND LiDAR SENSORS APPLIED TO UAV-BASED TOPOGRAPHIC SURVEYS IN AGRICULTURAL AREAS

Abstract

Remote sensing has become an essential tool for environmental monitoring and agricultural management, particularly with the advancement of Unmanned Aerial Vehicles (UAVs). This study aimed to conduct a comparative analysis of RGB and LiDAR sensors applied to topographic surveys in sugarcane cultivation areas, an activity that requires high altimetric accuracy for land leveling. The study was conducted at Fazenda Brasil, located in Suzanápolis, São Paulo, Brazil, using UAVs equipped with an RGB photogrammetric camera and a LiDAR sensor. Parameters such as flight altitude, image overlap, point density, processing time, presence of Ground Control Points (GCPs), and vegetation penetration capability were evaluated. The results demonstrated that the LiDAR sensor provides greater accuracy in generating the Digital Terrain Model (DTM), particularly in areas with dense vegetation and rugged terrain, due to its ability to penetrate vegetation cover and acquire information directly from the ground. The RGB sensor performed better in open areas and had lower operational costs, but showed limitations in altimetric definition in vegetated areas. It is concluded that, although both technologies have potential applications in precision agriculture, LiDAR is more efficient for surveys requiring greater accuracy in complex environments, whereas RGB may be a viable alternative in areas with lower topographic detail requirements.