Which statement best describes the role of ground stations in telemetry?

• A. Ground stations generate sensor data and actuation.
• B. Ground stations receive RF signals, demodulate, decode, time-stamp, store, and forward data.
• C. Ground stations only store data for later retrieval.
• D. Ground stations modulate signals for uplink and do not receive.

Answer: (B)

Ground stations on Earth are the data-handling bridge for spacecraft telemetry. Their main job is to receive the downlink RF signals, demodulate them to recover the baseband data, decode the telemetry packets, apply time-stamping to synchronize events, then store and forward that data to mission-control or data systems. This sequence—from receiving the signals to delivering usable data—is what turns radio waves into actionable telemetry for analysis and monitoring.

Ground stations don’t themselves generate sensor data or actuation; those come from the spacecraft’s onboard systems. They also aren’t limited to just storing data, nor are they only modulating uplink commands and not receiving. While uplink capabilities exist, the fundamental role highlighted here is the downlink data handling—receiving, processing, and delivering telemetry. That makes the described statement the best fit.