What instrument measures the velocity by Doppler shift from backscatter of aerosol particles?

A)
Doppler radar
B)
Laser pitot tube
C)
Rotating anemometer
D)
Laser velocimeter

Correct Answer :   Laser velocimeter


Explanation : In a laser velocitimeter, optical sensors are located within the aircraft and look out through the flow into the free stream. They measure the Doppler shift from backscatter of naturally occurring aerosol particles in the free stream.