Estudo sobre a utilização de alvos pré-sinalizados para apoiar levantamentos aerofotogramétricos realizados com veículo aéreo não tripulado (VANT)

The use of unmanned aerial vehicles (UAV) for mapping purposes increases annually in the survey market, mainly driven by the supply of new and more affordable equipment and easy operational handling, but there is still a lack of studies that definitively prove its effectiveness and reliability in terms of the accuracy of the results achieved, as well as studies to contribute to the improvement of their positional and altimetry performance. An alternative to optimize the performance of planialtimetric results of topographic surveys that use UAV, especially in areas where photoidentifiable points are either scarce or nonexistent to support checkpoints and ground control points, would be the implementation of photogrammetric ground control targets with coordinates collected through GNSS geodetic receivers and electronic levels. The installed landmarks aim to support the triangulation step and the orientation of the images during the processing steps, as well as serve as check points in order to verify the cartographic scale achieved. In this study, 14 landmarks were installed and pre-marked in an area that covers a road connection at the junction of state highways PB-044 and PB-008, with a total area of approximately 16.30 hectares. Finally, this article aims to show the steps that lead to the definition of the type, color, size and spatial distribution of photogrammetric ground control targets in an area of interest for roadway design project purposes and surveyed by aerial photogrammetry using UAV fitted with small-format camera