Which is the sensor's main function in a remote sensing system?

• A. Carry the payload
• B. Transmit data to the ground
• C. Detect radiation and convert it into electrical signals
• D. Store images

Answer: (C)

In remote sensing, the sensor’s role is to detect incoming radiation from the scene and convert that energy into electrical signals. This conversion is the essential step that turns what’s seen or measured in the environment into a electrical form that can be digitized, calibrated, and analyzed to produce images or data. Different sensors target different parts of the spectrum, but the common function is the same: translate radiant energy into a measurable electrical signal.

The other functions belong to different parts of the system. Carrying the payload is about the platform and hardware that support the instrument; transmitting data to the ground is handled by the data-link subsystem; storing images is managed by the onboard storage. But none of those can happen effectively without the sensor first converting radiant energy into an electrical signal.