A Review of Indoor UAV-based Tracking Systems: Classification, Status, and Challenges

The recent development of Unmanned aerial vehicle (UAV) technology and the UAVs' unique features offered the impetus for new UAV-based applications and services. The UAV's low maintenance cost, small size, outstanding maneuvering capability, and the possibility to be equipped with various technologies(e.g., sensors, cameras, and artificial intelligence (AI) systems) made the UAV-based systems suitable for performing autonomoustasks in indoor and hard-to-reach environments. One of the most promising applications of UAVs in indoor environments is autonomous monitoring and tracking. In this paper, we highlight the unique characteristics of UAV-based tracking systems, discussthe various system classifications based on the target behavior and the number of used UAVs, present some of the work that hasbeen done to design UAV-based indoor monitoring and tracking systems, and discuss the critical design challenges specific to indoor target tracking systems. Finally, we highlight some of the most promising technologies and solutions to develop effective UAV-based indoor monitoring and tracking systems.