A visibility study in Japanese urban area to collect environment profile for HEOs

This paper presents the methodology and result of our visibility experiment on mobile satellite communication. The main aim of this research is to find the optimal distance of space diversity for mobile satellite communication using Quasi Zenith Satellite. This experiment based on the assumption that microwave signal propagation from satellite to the mobile terminal (in this case a moving vehicle) is the same to the visible ray propagation, if this ray were transmitted from the satellite to the mobile terminal. Using this assumption, we developed an experiment scheme based on the optical visibility of the satellite. This experiment scheme consists of a fish eye camera that capture image in the range of 0-90 elevation and 0-360 azimuth. GPS was used to indicate the direction of satellite. The experiment was done at the Takaoka City in Takaoka Prefecture at the northwestern part of Japan. The area involved the urban and suburban area of the city. From the statistical value of the result, we found that the optimum distance for antenna diversity for this area to be 23 meters. We hope that this result will be useful to design mobile ambulance for real-time telemedical communication using satellite especially in Japan.