util.py 文件源码

def gps_newpos(lat, lon, bearing, distance):
    """Extrapolate latitude/longitude given a heading and distance
    thanks to http://www.movable-type.co.uk/scripts/latlong.html .
    """
    from math import sin, asin, cos, atan2, radians, degrees

    lat1 = radians(lat)
    lon1 = radians(lon)
    brng = radians(bearing)
    dr = distance / radius_of_earth

    lat2 = asin(sin(lat1) * cos(dr) +
                cos(lat1) * sin(dr) * cos(brng))
    lon2 = lon1 + atan2(sin(brng) * sin(dr) * cos(lat1),
                        cos(dr) - sin(lat1) * sin(lat2))
    return (degrees(lat2), degrees(lon2))