Aplicação de técnicas da fotogramétria digital com recurso a imagens colhidas por drones na produção de um Mapa planialtimétrico. estudo de caso: Bairro Chiango

Abstract

The objective of this work was to apply digital photogrammetric techniques to perform planialtimetric mapping using images obtained by cameras attached to drones. To this end, a flight was carried out with the drone equipped with a high-resolution camera and the images obtained were processed with the PIX4D Mapper software. Photogrammetric processing allowed the generation of Orthophotos, Digital Surface Models (DSM) and Digital Terrain Models (DTM). The Drone Deploy application, available for Android and iOS systems, was used at a height of 70 meters and with 80% lateral overlap and 30% longitudinal overlap. This application made it possible to plan the flight, taking into account the following parameters: speed: 3 m/s, flight altitude: 120 m, flight time: 45 min, photo capture: 2-3 seconds, image overlap: 80% lateral overlap and 30% frontal overlap. Based on the results obtained, it was possible to perform terrain restitution and obtain high precision in the survey, with marginal errors of less than 10 cm in relation to ground control points. These results show that this technique can be applied in several areas, such as urban planning, environmental monitoring and natural resource management, allowing the obtaining of precise information in a short period of time. Based on the results, it was possible to produce the topographic map of the photographed area. The precision of the results depended on several factors, such as the quality of the images obtained, the precision of the control points and the choice of processing parameters. The Root Mean Square Error (RMSE) was calculated, with a planimetric accuracy of 0.027 m, which means that, on average, the horizontal coordinates of the points in the results differed by approximately 0.027 m from the real coordinates, demonstrating a good level of accuracy in the planimetric measurements. Altimetric accuracy, the root mean square error (RMSE) was 0.043 m, which indicates that, on average, the altimetric differences between the calculated values ​​and the real values ​​were approximately 0.043 m. This suggests a satisfactory level of accuracy in the altimetric measurements. However, the results obtained demonstrated that the planialtimetric mapping technique using drones equipped with cameras and photogrammetric processing is a viable and efficient alternative for generating topographic and relief information. (TRADUÇAO NOSSA)