What is remote sensing and how is it used in civil engineering?

Remote sensing is the science of obtaining information about objects or areas from a distance, typically using satellites or aircraft. Sensors capture electromagnetic radiation reflected or emitted from Earth's surface. Civil engineering applications include: land use mapping, terrain analysis, flood mapping, monitoring construction progress, detecting ground subsidence, and infrastructure planning. Satellites like Landsat, Sentinel, and commercial providers offer imagery at various resolutions for different applications.