Geosite List Home Geosite The Shimosato Hydrographic Observatory The Shimosato Hydrographic Observatory Established in 1953. It had started surveying by means of satellites and laser distance measuring since 1983. This is the only Hydrographic Observatory in Japan. The facility is for making correct marine charts. Map The Shimosato Hydrographic Observatory 33.5778002,135.9368634,14 See in the map app