The maximum measurable range is determined by which parameter?

• A. Pulse Repetition Rate
• B. Pulse Width
• C. Receiver Gain
• D. STC

Answer: (C)

The key idea is that the farthest range you can measure unambiguously is set by how often you send pulses—the pulse repetition rate. After each transmission, the radar listens for echoes; if an echo from a distant target returns after the next pulse has already been sent, the system can’t tell which pulse the echo belongs to, causing range ambiguity. This unambiguous maximum range is determined by PRF, with the usual relationship R_unambiguous = c / (2 × PRF).

Pulse width mostly controls range resolution (how well you can distinguish two close targets) and affects minimum range; it doesn’t set how far you can unambiguously measure. Receiver gain changes how strong the received signal is and thus how far you can detect targets, but it doesn’t change the unambiguous range. STC helps suppress clutter and noise with range, not the fundamental limit on range measurement.