Which two categories are the main types of remote sensing?

The main types of remote sensing are categorized as passive and active. Passive remote sensing relies on detecting natural energy emitted or reflected from the Earth’s surface. This typically involves sensors that measure sunlight reflected by objects such as vegetation, water bodies, and urban areas. For example, satellite imagery that captures visible light or infrared radiation is a form of passive remote sensing.

On the other hand, active remote sensing involves emitting energy from a sensor and measuring the response that returns from the target. This technique uses its own source of energy, such as radar or LiDAR, to illuminate the area and gather data. Active remote sensing can provide detailed information regardless of sunlight availability and can penetrate cloud cover to some extent.

This distinction between passive and active methods is fundamental in remote sensing, as each type provides different data insights and is suited for various applications in fields such as environmental monitoring, agriculture, forestry, and urban planning.