中文说明：
读取IGS文件（观测文件*.*o 广播星历*.*n；精密星历*.sp3；修正电离层对流层）。均是matlab函数形式，可直接用于GPS matlab数据处理。
English Description：
Read IGS file (observation file *. * o broadcast ephemeris *. * n; precise ephemeris *. SP3; correction ionosphere troposphere). They are all matlab functions and can be directly used in GPS MATLAB data processing.