Description

Ground weather radars are surveillance sensors that are used to discover, assess and track hazardous weather (mostly CB clouds and associated phenomena such as thunderstorms and hail). They use the same operating principle as the Primary Surveillance Radar (PSR)), i.e. derive information from echoes received after transmitted electromagnetic pulses are reflected by the hydrometeors forming the clouds and the precipitations. However, instead of detecting aircraft and filtering out clutter (e.g. terrain and clouds) they focus on the airborne clutter. Since the size of the water particles in the clouds is much smaller than that of aircraft, weather radars operate much higher frequencies (3-10 GHz) and therefore, shorter wavelengths (10-3 cm) than PSR. Shorter wavelength radars can detect smaller particles at the expence of reduced range.