Which of the following is a radar signal characteristic?

• A. Antenna gain
• B. Pulse repetition interval - time between pulse starts
• C. Receiver sensitivity
• D. Modulation scheme

Answer: (B)

The main idea here is the timing of how the radar sends out its pulses. The pulse repetition interval is the time between the starts of consecutive transmitted pulses, and it is a fundamental property of the transmitted radar signal itself. This interval sets how often echoes can be expected and governs range and Doppler considerations, such as how far away a target can be unambiguously detected and how updates occur. The other options describe aspects not tied to the transmitted pulse timing: antenna gain is about how effectively the antenna radiates or gathers energy, receiver sensitivity is about the smallest signal the receiver can detect, and the modulation scheme concerns how the carrier is encoded but doesn’t define the spacing of pulses. Therefore, the time between pulse starts is the radar signal characteristic in question.