Which type of radar seeker does the AGM-84D Harpoon missile utilize?

• A. Passive radar seeker
• B. Semi-active radar seeker
• C. Active radar seeker
• D. Inertial seeker

Answer: (C)

The missile’s guidance sensor in the final phase is an onboard active radar seeker. That means the Harpoon D carries its own radar transmitter and receiver at the nose, so it can illuminate, detect, and track the target by itself without needing the launch platform to keep illuminating it. This is what makes it capable of stand-off, fire-and-forget style guidance in the terminal phase.

Why the other types don’t fit: a passive radar seeker relies on emissions from the target or environment to detect the target, not on the missile emitting its own radar. A semi-active radar seeker requires external illumination from the launch platform to be reflected off the target for the missile to sense. An inertial seeker uses inertial navigation without active tracking of the target. The Harpoon D specifically uses its own active radar in the terminal phase.