Question

select the correct answer
which description best explains how a doppler radar system works?
a. it reflects waves off of objects, measuring the difference of the waves it sends and receives.
b. it sends out a set of waves where each wave is preprogrammed to detect a certain kind of object.
c. it uses an antenna to measure the angle between two or more objects in distant space.
d. it uses the doppler effect to raise the pitch of sound waves so objects in distant space can be heard

Explanation:

A Doppler radar system operates by sending out waves and measuring the difference between the waves sent and received, which is based on the Doppler effect. It is used to detect motion and speed of objects. Option B is incorrect as it's not about pre - programmed waves for specific objects. Option C is about angle measurement which is not the main function of Doppler radar. Option D is wrong as Doppler radar uses electromagnetic waves, not sound waves for long - distance detection in the context of radar systems.

Answer:

A. It reflects waves off of objects, measuring the difference of the waves it sends and receives.