每经度程度公里​​数大约

The number of kilometers per degree of longitude is approximately

(2*pi/360) * r_earth * cos(theta)

其中， THETA 为度纬度和 r_earth 大约6378公里。

where theta is the latitude in degrees and r_earth is approximately 6378 km.

的每纬度的度数公里数大约相同，在所有位置，约

The number of kilometers per degree of latitude is approximately the same at all locations, approx

(2*pi/360) * r_earth = 111 km / degree 

所以，你可以这样做：

So you can do:

new_latitude  = latitude  + (dy / r_earth) * (180 / pi);
new_longitude = longitude + (dx / r_earth) * (180 / pi) / cos(latitude * pi/180);

只要 DX 和 DY 小比地球的半径，你没有得到太靠近磁极

As long as dx and dy are small compared to the radius of the earth and you don't get too close to the poles.