Watching over us The key technology for realizing the dreams described above is GPS. Using 24 satellites in orbit 20,000 kilometers above the earth, the system monitors all activity below 24 hours a day-activity ranging from something big like changes in the earth's crust to details as minute as the location of individual people and vehicles-taking in everything at a glance and able to pinpoint locations with precision.
天眼遙望地球以上夢想的關鍵技術正是全球定位系統，藉由二萬公里外地球軌道上的 24 顆衛星，24 小時遙望、紀錄地球一舉一動，大至地殼變動、山崩災害，小至人、車位置，可以一覽無遺、精準定位。