import math


def get_forward_angle(fix1, fix2):
    """Calculates forward azimuth between two positions in radians."""
    lat1 = math.radians(fix1.latitude)
    lon1 = math.radians(fix1.longitude)
    lat2 = math.radians(fix2.latitude)
    lon2 = math.radians(fix2.longitude)

    y = math.sin(lon2 - lon1) * math.cos(lat2)
    x = (math.cos(lat1) * math.sin(lat2)
               - math.sin(lat1) * math.cos(lat2) * math.cos(lon2 - lon1))
    angle = math.atan2(y, x)
    return (angle + 2 * math.pi) % (2 * math.pi)