Echo is defined as?

• A. Electronic signal that has been reflected back to the radar antenna
• B. The transmitted pulse
• C. The noise in the receiver
• D. The range measurement

Answer: (A)

Echo is the return signal—the portion of the transmitted radar pulse that is reflected off a target and arrives back at the radar receiver. After the radar emits a short pulse, some energy bounces off objects in the scene and travels back to the antenna; that returning energy is the echo and it provides the information used to determine how far away the target is (from the time delay). The transmitted pulse is the outgoing energy, not the echo. The noise in the receiver is unwanted random signal, not the reflected return. The range measurement is obtained from the echo’s travel time, not the echo itself.