Improvement of Satellite Visibility by Space Diversity consisted of Two Geostationary Satellites: -Aiming to High Performance Data Communication for Ambulance -

In the mobile moving picture transmission via a communication satellite between an ambulance and a hospital, it sometimes occurs that the electric wave is blocked by some building, tree, utility pole, etc. standing along the roadside. And consequently some packets of the transmitted signal are lost to result in freezing of the moving picture. By use of a fish-eye lens mounted on a mobile roof, the pictures of the sky including the roadside are recorded in three different Japanese urban areas (in the area of Ginza in Tokyo; in the area near the Sendai Station in Miyagi Prefecture; in the city area ofNagoya of Aichi Prefecture). In these three areas ,the satellite visibility to the communication satellite has been measured. The satellite visibility is a signpost indicating the freezing frequency of the moving picture. Then this paper proposes a novel technique for improving the satellite visibility by space diversity consisted of two geostationary satellites. The effect of such improvement has been confirmed by practicing simulations in those three Japanese urban areas.