中文说明：这是国外关于卫星导航方面一书的源代码，相信对初学者会有很大的帮助，里面包含位置计算、星历计算、模糊度计算等功能。
English Description：
This is a foreign book on satellite navigation source code, I believe it will be of great help to beginners, which includes position calculation, ephemeris calculation, ambiguity calculation and other functions.