GPS

Compass Satellite Navigation System
It is reported that this is the fourth Compass satellite ever being launched, the former three being launched on 31, 10, 2000; 21, 12, 2000; and 25, 5, 2003 respectively.
Galileo由30颗轨道卫星组成，将在2005年至 2008年全部发射升空，基本投资在32亿至36亿 欧元之间，投资额相当于在欧洲建一个小型机场， 或者说建150公里长的高速公路。伽利略将同时开 拓军民两用领域，它还可兼容美国的GPS和俄罗斯 的Glonass。
Glonass Satellite Navigation System
Compass Satellite Navigation System
中国北斗导航卫星系统
Compass Satellite NavigBaidu Nhomakorabeation System
At 0: 28 am, 3, Feb, 2007, a Compass navigation satellite was launched atop a Long March 3-A carrier rocket at Xichang Satellite Launch Center. 2007年2月3日零时 28分，我国在西昌卫 星发射中心用“长征 三号甲”运载火箭， 成功将北斗导航试验 卫星送入太空。
Global Positioning System
GPS was first developed in 1973. After 20 year’s improvement and at the cost of $ 20 billion, it was completed and put to use in 1994.
Smart Cars
Michio Kaku
Global Positioning System
GPS and some other systems
The U.S.A GPS Europe
Galileo Russia Glonass China Compass
Global Positioning System
Compass Satellite Navigation System
Up to now, Compass has operated stably and smoothly, playing an important part in mapping, communication, water conservancy, transportation, exploration and national security.
Global Positioning System
Today, GPS is widely used in many countries in the world, and America has made a huge profit from it. But in order to prevent other countries’ threat to America by using GPS, America only provides low precision satellite signals to foreign countries, while high precision signals are reserved for U.S. military forces.
北斗导航试验系统运行至今工作稳定、状态良好，已在测 绘、电信、水利、交通运输、勘探和国家安全等诸多领域 逐步发挥重要作用。
伽利略卫星导航系统
Galileo Satellite Navigation System
only enough for building small scale airport or 150 km highway. It is developed for both military and civil use, and designed to be compatible with GPS and Glonass.
Global Positioning System
Space-based radio-navigation system, consisting of 24 satellites and ground support. GPS provides users with accurate information about their position and velocity, as well as the time, anywhere in the world and in all weather conditions. With information about the ranges to three satellites and the location of the satellite when the signal was sent, the receiver can compute its own three-dimensional position.
1973年，美国开始研制全球定位系统GPS，经过 20年的不断完善，耗资200亿美元后，该系统终于 在1994年全面建成。
Global Positioning System
在军事上，这套系统 可以为战机、军舰和 导弹等导航，并锁定 攻击目标；在民用方 面，它可以为飞机、 船舶和汽车等导航。 In military affaires, GPS can not only navigate fighters, war ships and missals, but also help them to fix and attack targets. In civil use, it can navigate cars, ships and planes.
Galileo Satellite Navigation System
Galileo consists of 30 satellites, which will be launched into orbits between 2005 and 2008. the whole investment is 3.2-3.6 billion,
为打破美国的垄 断，俄罗斯耗资 30多亿美元建起 了自己的全球卫 星导航系统 GLONASS (格洛纳斯)。
Glonass Satellite Navigation System
到2007年底，“格 洛纳斯”系统的导航 信号已覆盖俄全境， 而到2009年年底之 前，将可覆盖到全球 的每一个角落，足以 与美国GPS系统相抗 衡。 By the end of 2007, Glonass navigation signals had covered whole Russian territory, and by the end of 2009, every corner of the world, good enough to match GPS.
Global Positioning System
Whenever necessary, America can stop others from using GPS, thus leaving their planes and ships paralyzed. 目前，GPS为世界各国所采用，美国从中赚取了巨额 的利润。但是，为了防范“某些国家”的军队利用 GPS威胁美国，美国只向外国提供低精度的卫星信号； 对美军则提供最精确的信号。一旦需要，美国可随时 切断向某些国家发送的信号，使这些国家的飞机、舰 船等陷于“瘫痪”。
俄罗斯“格洛纳斯”导航卫星系 统
Glonass Satellite Navigation System
In order to break the U.S. monopoly, Russia invested some $ 3 billion to develop its own Glonass Satellite Navigation System.