diffusiomètre à hyperfréquences

CONT: Diffusomètre micro-ondes pour la mesure de la vitesse et de la direction des vents.
CONT: Cette carte établie à partir des données du satellite américain QuikSCAT défilant à 800 km d'altitude grâce à l'instrument SeaWinds, diffusiomètre micro-onde à haute fréquences, qui permet d'effectuer des observations à travers les nuages et de mesurer la vitesse moyenne des vents à 10 mètres au-dessus du niveau de l'océan.

CONT: Instrumentation flown on Seasat included a radar altimeter, a microwave scatterometer for measuring surface wind speed and direction, a scanning multichannel microwave radiometer for sea surface temperature, a visible and infrared radiometer, and the first spaceborne synthetic aperture radar.
CONT: Microwave scatterometer ... measures the microwave scattering or reflective properties of surfaces. It is also non-imaging, and is specifically designed to measure backscattering. This requires that it detect more detailed spectral information than imaging radar but has reduced spatial resolution and aerial coverage. The surface is scanned in two or more directions, usually by multiple sensors. The primary application of microwave scatterometers is to measure wind vectors (that is, speed and direction) over the ocean surface. This is based on the principle of ocean 'roughness' being caused by wind and resulting in a characteristic surface pattern which may be identified by its scattering properties.