Steps to build a DIY low-cost fixed-wing drone for biodiversity conservation

In addition to an orthomosaic map, we also created maps to analyze the quality of vegetation, known as healthy green vegetation or plant health maps. These maps show how green the images are through the Visible Atmospherically Resistant Index (VARI), since this index is used for images obtained from an RGB sensor (Fig 6). The vegetation health map was created from images of the visible spectrum (Red, Green, Blue) obtained by the RGB sensor using the formula: VARIgreen = (Rgreen−Rred) / (Rgreen + Rred−Rblue) [26]. Knowing that the images obtained are from the visual spectrum, we considered the standard CIR Calibration of Agisoft Metashape and filtered the values obtained between 0.06 and 0.39 of each raster. Discussion In this study we describe the step-by-step process for the development of a DIY low-cost drone that allows performing basic biodiversity-related studies in large areas. We present the steps in a simple and flexible way, aiming to help researchers with basic electronics knowledge and with limited financial resources to develop their own drone system. We describe the Fig 6. Georeferenced orthomosaic and health vegetation map. Images with a 20x zoom of an open trail in the vegetation and a deforestation area with some irregular structures. https://doi.org/10.1371/journal.pone.0255559.g006 PLOS ONE Building a DIY low-cost fixed-wing drone for biodiversity conservation PLOS ONE | https://doi.org/10.1371/journal.pone.0255559 August 13, 2021 12 / 17