Which radar type requires a transponder (XPDR) and does not display weather?

The correct choice is SSR, which stands for Secondary Surveillance Radar. This type of radar relies on the aircraft's transponder for identification and altitude reporting, enhancing situational awareness for air traffic controllers. Unlike Primary Surveillance Radar (PSR), which detects target echoes directly from objects in the air, SSR uses the signals transmitted from a transponder mounted on the aircraft.

Moreover, SSR primarily serves the purpose of aircraft surveillance and does not display weather information. Weather radar, on the other hand, specifically detects atmospheric conditions such as precipitation and storm activity but is not used for tracking aircraft in the same manner. Ground radar is designed to support operations at airports, assisting with the movement of aircraft on the ground, and can include both SSR and weather detection capabilities.

Therefore, SSR’s reliance on transponder signals and its focus on providing surveillance data rather than weather information distinguishes it clearly as the radar type in question.