This video is an introduction of the synthetic aperture radar (SAR) systems in remote sensing: active microwave sensors, components and working principle of a Side Looking Airborne System (SLAR). Concepts and influence of the system wavelength and polarization, radiometry of SAR images. Brief description of Copernicus Sentinel-1 images. Ruiz Fernández, LÁ. (2024). Introduction to SAR images. https://riunet.upv.es/handle/10251/205044 DER