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

Light Detection and Ranging (LiDAR) is a commonly used active sensor in remote sensing payloads due to its ability to provide precise distance measurements and create detailed three-dimensional maps of the environment. LiDAR works by emitting laser light pulses towards the ground and measuring the time it takes for the emitted light to reflect back to the sensor. This enables the collection of accurate elevation data and surface features, making it particularly valuable in applications such as topographic mapping, forestry, and urban planning.

While radar imaging can also be classified as an active sensor and is utilized for mapping and surveillance, it operates on different principles and applications compared to LiDAR. Ultrasonic sensors are typically used for short-range distance measurement and are not as common in aerial remote sensing applications. Thermal imaging sensors, on the other hand, detect infrared radiation and are primarily passive sensors, capturing the emitted thermal energy from objects rather than actively emitting their own signals.