kOS.GeoCoordinates.GetHeadingFromVessel C# (CSharp) Method

        public float GetHeadingFromVessel(Vessel vessel)
        {
            var up = vessel.upAxis;
            var north = VesselUtils.GetNorthVector(vessel);

            var targetWorldCoords = vessel.mainBody.GetWorldSurfacePosition(Lat, Lng, vessel.altitude);

            var vector = Vector3d.Exclude(vessel.upAxis, targetWorldCoords - vessel.GetWorldPos3D()).normalized;
            var headingQ = Quaternion.Inverse(Quaternion.Euler(90, 0, 0) * Quaternion.Inverse(Quaternion.LookRotation(vector, up)) * Quaternion.LookRotation(north, up));

            return headingQ.eulerAngles.y;
        }