Question

Select the example of active sensor in remote sensing, from the following sensors

• A. \( \text{Laser scanner} \)
• B. \( \text{Return beam vidicon} \)
• C. \( \text{Television camera} \)
• D. \( \text{Electro-optical scanner} \)

Hint:

Remember that active sensors 'actively' send out energy, while passive sensors 'passively' receive naturally available energy.

Answer 1

The Correct Option is A

Active sensors in remote sensing provide their own source of energy to illuminate the target. \begin{itemize} \item Laser scanner (LiDAR) emits laser pulses and measures the reflected energy to determine distances and create 3D models. This is an active sensor. \item Return beam vidicon, television camera, and electro-optical scanners are passive sensors; they detect naturally reflected or emitted electromagnetic radiation from the Earth's surface. \end{itemize}