radarsatelliter

Radarsatelliter is not a widely used term in formal space or remote-sensing literature. In some contexts, it is a compound word formed from radar and satellite with the -er suffix to denote a satellite that carries a radar instrument and provides radar imagery of the Earth's surface. More commonly, such platforms are referred to as radar satellites or synthetic-aperture radar (SAR) satellites.

A radar satellite carries an active radar sensor, typically a SAR instrument, which emits radar pulses and measures the reflected signals from the surface. This enables imaging regardless of daylight and weather conditions, making radar satellites valuable for continuous Earth observation. They operate in various frequency bands (for example L-, C-, and X-band) and can use different polarizations to extract surface properties. Orbit design and swath configuration determine revisit times, spatial resolution, and coverage.

Data produced by radar satellites include backscatter measurements (sigma naught), SAR intensity images, and, for suitable missions, interferometric products such as coherence maps and digital elevation models. Polarimetric SAR expands capabilities by capturing multiple polarization channels, improving feature discrimination and surface characterization.

Applications of radarsatelliter-type satellites are broad: disaster response and damage assessment, land-use and urban expansion monitoring, forestry and agriculture, ice and ocean monitoring, and geophysical studies such as deformation mapping. Notable examples of radar satellites include RADARSAT-1 and RADARSAT-2 (Canada), TerraSAR-X and TanDEM-X (Germany), Sentinel-1 (European Space Agency), and ALOS-2 (Japan). These platforms illustrate the range of capabilities associated with radar satellites, the archetype described by the term radarsatelliter.