It makes use of the GPS -- you're familiar with GPS in your automobile, but you may not be familiar with the fact that there's a GPS U.S., there's a Russian GPS, and there's a new GPS system going to Europe, called Galileo.
空中之路利用GPS——你们很熟悉汽车使用的GPS 但是你们可能不熟悉这样的事实：不仅有美国GPS 还有俄罗斯GPS， 另外有一个新的GPS系统 即欧洲的伽利略GPS系统。