可以IGS网站下载GPS精密星历的sp3 格式(download the GPS precise ephemeris in sp3 float)

查阅相关资料，自己总结IGS精密星历文件，例如clk钟差文件，sp3文件 每行数据代表什么(Consult the relevant information and summarize the IGS precision ephemeris files, such as the CLK clock difference file, and what the SP3 files per line of data represent)