Data transmission to ships and local positioning system using the Japanese domestic geostationary satellites

In Japan, the test transmission of satellite broadcasting started in 1984. It is expected that the spilt power will reach a wide area of the surrounding Japanese waters, even though the power is focused on the Japanese Islands. Thus it can be used as a convenient medium of information transmission to domestic vessels as well as for TV programs. The authors designed a device with a 2-axis automatic steering mechanism for onboard reception. The device has been used to measure the oceanic field strength of the transmitting satellites power and also for data reception from the Japanese meteorological satellite (CMS). Cloud images thus received offer important meteorological data which helps to infer the optimal route for ocean going vessels. The authors checked the tracking performance and also observed the field strength in the Pacific and Indian Oceans. They are also developing a positioning system for vessels steaming around the Japan´s coastal sea using of domestic geostationary satellites