Alessio Martinelli received a master's degree cum laude in telecommunication engineering and a Ph.D. degree in information engineering from the University of Florence (Italy), in 2013 and 2017, respectively. He has been a research fellow with the Department of Information Engineering of the University of Florence. Currently, he is a navigation system engineer at Telespazio, working on GNSS navigation service monitoring and validation of GNSS solutions. His research activity is mainly focused on positioning and navigation solutions: ultra-wide band positioning, cooperative GNSS positioning, GNSS/INS integration techniques, and pedestrian dead reckoning (PDR) navigation.