说明：  GDOP(Geometric Dilution of Precision) 几何精度因子是衡量一个定位系统精度的重要标准之一。 运行程序sGDOP.m可得到三站GDOP仿真结果，更改程序中s_x,y,z可以更改阵列的几何排列。运行程序fGDOP.m得到四站GDOP仿真结果。
(GDOP (geometric division of precision) geometric accuracy factor is one of the important standards to measure the accuracy of a positioning system. Running the program sgdop. m, we can get the simulation results of three stations GDOP, and changing the geometry of the array by changing the program s _ x, y,z. Running the program fgdop.m, the simulation results of four stations GDOP are obtained.)