A ROS multi-tier UAV localization module based on GNSS, inertial and visual-depth dataA ROS multi-tier UAV localization module based on GNSS, inertial and visual-depth data Peer-Reviewed Journal Publication Δημοσίευση σε Περιοδικό με Κριτές 2023-08-232022enThis research has been co-financed by the European Union and Greek national funds through the Operational Program Competitiveness, Entrepreneurship and Innovation, under the call RESEARCH–CREATE–INNOVATE (project code: T1EDK-03209).Uncrewed aerial vehicles (UAVs) are continuously gaining popularity in a wide spectrum of applications, while their positioning and navigation most often relies on Global Navigation Satellite Systems (GNSS). However, numerous conditions and practices require UAV operation in GNSS-denied environments, including confined spaces, urban canyons, vegetated areas and indoor places. For the purposes of this study, an integrated UAV navigation system was designed and implemented which utilizes GNSS, visual, depth and inertial data to provide real-time localization. The implementation is built as a package for the Robotic Operation System (ROS) environment to allow ease of integration in various systems. The system can be autonomously adjusted to the flight environment, providing spatial awareness to the aircraft. This system expands the functionality of UAVs, as it enables navigation even in GNSS-denied environments. This integrated positional system provides the means to support fully autonomous navigation under mixed environments, or malfunctioning conditions. Experiments show the capability of the system to provide adequate results in open, confined and mixed spaces.http://creativecommons.org/licenses/by/4.0/Drones66Antonopoulos_et_al_Drones_6(6)_2022.pdfChania [Greece]Library of TUC2023-08-23application/pdf128.1 MBfree Antonopoulos Angelos Αντωνοπουλος Αγγελος Lagoudakis Michail Λαγουδακης Μιχαηλ Partsinevelos Panagiotis Παρτσινεβελος Παναγιωτης MDPI UAV Drone Navigation Localization ROS Simultaneous Localization and Mapping (SLAM) GNSS Real-Time Kinematics (RTK) Inertial Measurement Unit (IMU)