@article {Cesetti2010233,
	title = {A Vision-based guidance system for UAV navigation and safe landing using natural landmarks},
	journal = {Journal of Intelligent and Robotic Systems: Theory and Applications},
	volume = {57},
	number = {1-4},
	year = {2010},
	note = {cited By 45},
	pages = {233-257},
	abstract = {In this paper a vision-based approach for guidance and safe landing of an Unmanned Aerial Vehicle (UAV) is proposed. The UAV is required to navigate from an initial to a final position in a partially known environment. The guidance system allows a remote user to define target areas from a high resolution aerial or satellite image to determine either the waypoints of the navigation trajectory or the landing area. A feature-based image-matching algorithm finds the natural landmarks and gives feedbacks to an onboard, hierarchical, behaviour-based control system for autonomous navigation and landing. Two algorithms for safe landing area detection are also proposed, based on a feature optical flow analysis. The main novelty is in the vision-based architecture, extensively tested on a helicopter, which, in particular, does not require any artificial landmark (e.g., helipad). Results show the appropriateness of the vision-based approach, which is robust to occlusions and light variations. {\textcopyright} 2009 Springer Science+Business Media B.V.},
	doi = {10.1007/s10846-009-9373-3},
	url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84893415343\&partnerID=40\&md5=1af91a05c14c688e97131ab24f43e2bd},
	author = {Cesetti, A. and Emanuele Frontoni and Adriano Mancini and Primo Zingaretti and Sauro Longhi}
}
