GPS定位原理的简单实现。利用已知坐标的四个固定点及终端到四个点的距离，得到终端的位置，即三维坐标,利用了Jacobi算法-GPS positioning principle of simple implementation. Using the known coordinates of the four fixing points and end points of the distance of four to obtain a position of the terminal, i.e., three-dimensional coordinates，using Jacobi Algorithm