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.