▍1. GPS-postion-Nav-source
gps定位程序 测试通过，可以直接拿来用 GPS卫星提供了P码（精码）和C/A码（粗码）两种定位服务。P码为军方服务，定位精度达到3米；C/A码对社会开放，定位精度为14米。出于自身安全的考虑，美国先后实施了SA和AS政策。SA政策在C/A码中人为引入了误差，使定位精度下降到100米；AS政策则对P码实行加密。 由于GPS对社会开放，因此各类接收机、测量设备如雨后春笋般涌现，并广泛应用于各行各业，彻底改变了传统的定位导航方式.(gps positioning program testing by direct use of them GPS satellites provide two kinds of location-based services in the P-code (precise code) and the C/A code (coarse code). P code for military service, positioning accuracy of 3 meters C/A code of the open society, positioning accuracy of 14 meters. For their own security reasons, the United States has implemented a policy of SA and AS. SA policy is artificially introduced in the C/A code of the error, so that the positioning accuracy down to 100 meters AS policy is implemented in P-code encryption. GPS open society, the various types of receivers, measuring equipment have sprung up, and are widely used in all walks of life, completely changed the traditional positioning and navigation.)
