Which radar method provides velocity information via Doppler shift?

Which radar method provides velocity information via Doppler shift?

• A. Pulse Modulation
• B. Frequency Modulation
• C. Continuous Wave (CW)
• D. Pulse Doppler

Answer: (D)

Velocity information comes from the Doppler effect: a moving target causes a shift in the frequency of the returned echo, and that shift encodes the radial speed. A pulsed radar can measure range from the time of flight, and when Doppler processing is applied to the echoes from those pulses, it extracts the Doppler shift to determine velocity. This combination—pulsed transmissions plus Doppler processing—is what Pulse Doppler uses, giving both range and speed information from the same data. A continuous-wave system can detect Doppler shifts to find velocity, but it can’t determine range, which is why the pulsed, Doppler-processing approach is preferred for full target profiling. The other options don’t inherently provide velocity information through Doppler processing in the same integrated way.

Velocity information comes from the Doppler effect: a moving target causes a shift in the frequency of the returned echo, and that shift encodes the radial speed. A pulsed radar can measure range from the time of flight, and when Doppler processing is applied to the echoes from those pulses, it extracts the Doppler shift to determine velocity. This combination—pulsed transmissions plus Doppler processing—is what Pulse Doppler uses, giving both range and speed information from the same data.

A continuous-wave system can detect Doppler shifts to find velocity, but it can’t determine range, which is why the pulsed, Doppler-processing approach is preferred for full target profiling. The other options don’t inherently provide velocity information through Doppler processing in the same integrated way.