五十年代未，原苏联发射了人类的第一颗人造地球卫星，美国科学家在对其的跟踪研究中，发现了多普勒频移现象，并利用该原理促成了多普勒卫星导航定位系统TRANsIT的建成，在军事和民用方面取得了极大的成功，是导航定位史上的一次飞跃。为了提高卫星定位的精度，美国从1973 年开始筹建全球定位系统GPS -Not the fifties, the former Soviet Union launched the mankind s first artificial Earth satellite, the U.S. scientists in their follow-up study, found the phenomenon of Doppler shift, and led to use of the principle of Doppler satellite navigation and positioning system TRANSIT completed, in the military and civilian achieved a great success, is the history of navigation and positioning of the first leap. In order to improve the accuracy of satellite positioning, the United States since 1973 to build the Global Positioning System GPS