radar météorologique au sol

CONT: Ground-based weather radars emerged during World War II and have since been used to observe precipitation, mostly over land. Ground-based radars send out pulses of microwave energy in narrow beams that scan in a circular pattern. When the microwave pulse encounters precipitation particles in the atmosphere, the energy is scattered in all directions, sending some energy back to the radar. These measurements are used to estimate intensity, altitude, precipitation type (e.g., rain, snow, hail), and motion. Obtaining continuous measurements of precipitation from ground-based systems (e.g., from rain gauges and radar systems) presents a challenge due to large gaps between monitoring sites on land and huge gaps over the ocean.