def computerOffsetPosition(lon, lat, brng, dist):
lat1 = lat * pi / 180
lon1 = lon * pi / 180
brg = brng * pi / 180
# 扁率
flat = 298.257223563
# 地球 半长轴
a = 6378137.0
# 地球 半短轴
b = 6356752.314245
f = 1 / flat
sb = sin(brg)
cb = cos(brg)
tu1 = (1 - f) * tan(lat1)
cu1 = 1 / sqrt((1 + tu1 * tu1))
su1 = tu1 * cu1
s2 = atan2(tu1, cb)
sa = cu1 * sb
csa = 1 - sa * sa
us = csa * (a * a - b * b) / (b * b)
A = 1 + us / 16384 * (4096 + us * (-768 + us * (320 - 175 * us)))
B = us / 1024 * (256 + us * (-128 + us * (74 - 47 * us)))
s1 = dist / (b * A)
s1p = 2 * pi
cs1m = 0.0
ss1 = 0.0
cs1 = 0.0
ds1 = 0.0
#
while abs(s1 - s1p) > 1e-12:
cs1m = cos(2 * s2 + s1)
ss1 = sin(s1)
cs1 = cos(s1)
ds1 = B * ss1 * (cs1m + B / 4 * (cs1 * (-1 + 2 * cs1m * cs1m) - B / 6 * cs1m * (-3 + 4 * ss1 * ss1) * (-3 + 4 * cs1m * cs1m)))
s1p = s1
s1 = dist / (b * A) + ds1
t = su1 * ss1 - cu1 * cs1 * cb
lat2 = atan2(su1 * cs1 + cu1 * ss1 * cb, (1 - f) * sqrt(sa * sa + t * t))
l2 = atan2(ss1 * sb, cu1 * cs1 - su1 * ss1 * cb)
c = f / 16 * csa * (4 + f * (4 - 3 * csa))
l = l2 - (1 - c) * f * sa * (s1 + c * ss1 * (cs1m + c * cs1 * (-1 + 2 * cs1m * cs1m)))
lon2 = lon1 + l
Longitude = lon2 * 180 / pi
Latitude = lat2 * 180 / pi
return (Longitude, Latitude)
