Advanced Receiver Autonomous Integrity Monitoring (ARAIM) is a next-generation of a conventional RAIM and is expected to be used as air navigation with less than RNP 0.3NM horizontal guidance and vertical guidance, that could not be achieved by the conventional RAIM. ARAIM is the global service of GNSS navigation that it is based on using multiconstellation satellites and L1/L5 dual frequency signals. It also has a function of fault detection and exclusion (FDE) to eliminate the multiple satellite faults within a constellation on its own. Therefore, the aviation users can get more integrity and availability than conventional RAIM. In order to realize these, Integrity Support Message (ISM) is introduced to dynamically provide the priori risk of a satellite fault etc. In addition, in order to cope with multiple satellite failures, Multiple Hypothesis Solution Separation (MHSS) will be adopted. This paper explains the ARAIM concept, theory of integrity and FDE algorithm based on Milestone 3 Report issued by the ARAIM Technical Subgroup in EU-U.S. Cooperation on Satellite Navigation.

Usage of new means of transportation such as unmanned aircraft systems (UAS) or new flying vehicles is being actively promoted in both of Japan and overseas. The airspace where such new means of transportation are expected in lower airspace than the airspace passenger airplanes fly. So, a study of new air traffic management schemes targeting the lower airspace has recently occurred. It is important to understand the current utilization of the targeting airspace when considering air traffic management. In order to grasp the lower level airspace utilization in Japan, the flight plan and related information were referred and the trend of VFR flight was analyzed. It is important to note that the flights not being obligated to submit flight plan exist, but the results clarified the statistical values of the flight purpose and flight time of VFR flight in Japan. It will be useful for the future study of air traffic management at low level airspace.