//! @return the sphero's heading without relying on vision - before vision is primed this appears more correct
private float ComputeSpheroHeadingCalibration()
{
const float angularCorrection = -90.0f;
// get the sphero position data to work out the angle to the sphero
Vector3 spheroPosition = VisionUtils.s_spheroToUnityTransform * SpheroNativePosition();
float angleToSphero = Mathf.Atan2(spheroPosition.z, spheroPosition.x) * Mathf.Rad2Deg;
return(sphero.ApplyCalibrationToHeading(SpheroYaw) + angleToSphero + angularCorrection);
}