全球定位系统(GPS)是本世纪70 年代由美国陆海空三军联合研制的新一代空间卫星导航定位系统，其主要目的是为陆、海、空三大领域提供实时、全天候和全球性的导航服务。由于GPS 可以为用户提供动态目标的三维位置、三维速度和时间信息，具有精度高、能够实时定位的特点，因此目前成为车辆导航，监控中进行定位的首选方案。-Global Positioning System (GPS) is the 70s of this century by the U.S. Army to jointly develop a new generation of space satellite navigation and positioning system, its main purpose is for land, sea and air to provide real-time three main areas, all-weather and global navigation services. As the GPS can provide users with the goal of dynamic three-dimensional position, three-dimensional velocity and time information, with high precision, to the characteristics of real-time location, it has become the vehicle navigation, positioning monitoring program of choice.