Which active sensor is used in a remote sensing payload?

Which active sensor is used in a remote sensing payload?

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

Answer: (B)

Active sensors emit their own energy and measure the return to gather data. LIDAR does this by sending short laser pulses toward the ground and timing their round trip. That time-of-flight measurement yields precise distance data, which lets you build detailed 3D point clouds and elevation models for the scene. This capability—probing the environment actively with light—makes LIDAR a quintessential active sensor for drone-based remote sensing. In contrast, a thermal camera is passive; it just detects infrared radiation objects emit without emitting anything itself. Sonar is designed for underwater use, relying on sound waves in water rather than air. Radar is another active option, using radio waves, and it’s certainly used in remote sensing, but LIDAR’s high spatial resolution and straightforward 3D data make it the common pick for many drone remote sensing payloads.

Active sensors emit their own energy and measure the return to gather data. LIDAR does this by sending short laser pulses toward the ground and timing their round trip. That time-of-flight measurement yields precise distance data, which lets you build detailed 3D point clouds and elevation models for the scene. This capability—probing the environment actively with light—makes LIDAR a quintessential active sensor for drone-based remote sensing.

In contrast, a thermal camera is passive; it just detects infrared radiation objects emit without emitting anything itself. Sonar is designed for underwater use, relying on sound waves in water rather than air. Radar is another active option, using radio waves, and it’s certainly used in remote sensing, but LIDAR’s high spatial resolution and straightforward 3D data make it the common pick for many drone remote sensing payloads.