In the radar range equation, what does R represent?

• A. Signal power
• B. Receiver sensitivity
• C. Range to the target
• D. Radar cross-section

Answer: (C)

R represents the distance from the radar to the target. In the radar range equation, this distance governs how much energy propagates to the target and then back to the receiver, so the received power falls off with range. In the common monostatic form, the two-way travel causes the received power to vary with the fourth power of the range, meaning doubling the distance reduces the received signal by a factor of 16. This highlights how crucial range is for detection: small changes in distance dramatically affect what the radar can pick up. The other quantities in the equation describe how strong the signal is and how the target reflects it, but they are not what R signifies.