本代码用于模拟卫星星下点在地球表面上的投影。可以在程序中给定六要素及其他相关参数，就可以利用MATLAB呈现出仿真图。-The code for a simulated satellite point on the Earth' s surface projection. May be given in the program six elements and other relevant parameters, you can use MATLAB simulation showing a map.