Qualitative effectiveness of unmanned aerial vehicles for monitoring forest restoration in Brazil

Images obtained by sensors installed on unmanned aerial vehicles (UAVs), commonly called drones, can be used for several environmental applications such as monitoring the use of soil, estimating biomass, and determining the carbon stock of native vegetation and forest restoration projects. The increased use of this technology is due to the easy operation, high spatial resolution of the orthorectified and georeferenced mosaics, precision of the cartographic products, and generation of topography information on the study targets. The present study assesses the effectiveness of UAV in generating images of forest restoration areas in two Brazilian biomes: Cerrado and Amazon. The operational aspects and data quality were analyzed using four different aircraft models. Among the tested aircrafts, the rotary wing category (quadcopter) showed the highest effectiveness for monitoring forest restoration projects. Compared with the fixed-wing models, this equipment was characterized by easier field operation and logistics, better resistance to strong winds, versatility in takeoff and landing, with well stabilized images with little or no drag.