This source code for calculate of element of satellite.

计算卫星位置用的，源代码，包括很多，比如sgp4模型-Used in calculating the satellite position, the source code, including many, such as model sgp4

由david vallado更新的轨道确定的程序代码，本程序融合sgp4和sdp4，包含193个文档-this procedure is the sgp4 prediction model from space command. this is an updated and combined version of sgp4 and sdp4