Electronic Navigation Research InstituteEditorial board: -Shigeru Ozeki, Deputy Director of the Surveillance and Communication Department, Electronic Navigation Research Institute (ENRI), Chofu, Tokyo, Japan -Jean-Marc Loscos, Chef du pôle Systèmes d’Alertes et Séparations, Direction des Services de la Navigation Aérienne (DSNA), Toulouse, France -Dong Min Kim, Principal researcher, Korea Aerospace Research Institute (KARI), Daejeon, Korea -Masatoshi Harigae, Supervisor of flight operation and safety technology group, Japan, Aerospace Exploration Agency (JAXA), Chofu, Tokyo, Japan -Takeshi Tsuchiya, Associate Professor, University of Tokyo, Tokyo, Japan -Ken Ito, Principal Researcher, ENRI -Masato Fujita, Senior Researcher, ENRI