Robin
Well-known member
How do they use a speed gun? The doppler shift is proportional to angle of the gun to the vessel. Easily contolled on a road, where the road constrains direction of travel. In a situation with 2 degrees of freedom, you'd need 2 orthoganal speed guns to work out the scalar product. Plus, how do they null out wave returns?
Plus, they are quite difficult to keep in calibration. I'd be asking for that certificate.
Are you volunteering to test the theory?