What type of active sensor is used in a remote sensing payload?

What type of active sensor is used in a remote sensing payload?

• A. RADAR
• B. LIDAR
• C. SONAR
• D. Thermal camera

Answer: (B)

Active sensing means the system emits energy and then measures the return from the target. A drone’s remote sensing payload commonly uses LIDAR, which sends laser pulses toward the ground and calculates distance from the time it takes for each pulse to bounce back, producing precise 3D maps. This energy emission and reflection process is what makes LIDAR an active sensor. Other options either rely on emitted energy in different domains or do not emit energy: thermal cameras detect infrared radiation emitted by objects (they are passive), sonar uses sound waves and is intended for underwater use, and radar also emits energy but is less typical on small drone payloads for high-resolution mapping, though it is an active sensor as well. Thus, LIDAR best fits the description of an active sensor used in a remote sensing payload for drones.

Active sensing means the system emits energy and then measures the return from the target. A drone’s remote sensing payload commonly uses LIDAR, which sends laser pulses toward the ground and calculates distance from the time it takes for each pulse to bounce back, producing precise 3D maps. This energy emission and reflection process is what makes LIDAR an active sensor. Other options either rely on emitted energy in different domains or do not emit energy: thermal cameras detect infrared radiation emitted by objects (they are passive), sonar uses sound waves and is intended for underwater use, and radar also emits energy but is less typical on small drone payloads for high-resolution mapping, though it is an active sensor as well. Thus, LIDAR best fits the description of an active sensor used in a remote sensing payload for drones.