What types of weather radar are there?

Any radar without Doppler performance is called incoherent radar or conventional weather radar, and radar with Doppler performance is called coherent radar or Doppler radar. The main weather radars are:

Cloud radar

It is a radar used to detect the height, thickness and physical characteristics of clouds without precipitation. Its common wavelength is 1.25 cm or 0.86 cm. The working principle is the same as that of rain radar, which is mainly used to detect the height of cloud top and cloud bottom. If there are more than one cloud in the sky, the height of each layer can be measured. Because cloud particles are smaller than precipitation particles, the working wavelength of cloud radar is shorter. Cloud radar can only detect middle and high-level clouds with less clouds. For low-level clouds with large water content, such as cumulonimbus clouds and hail, the beam of cloud radar is difficult to penetrate and can only be detected by rain radar.

weather radar

Also known as weather radar, it uses the scattering effect of raindrops, cloud droplets, ice crystals and snowflakes on electromagnetic waves to detect the concentration, distribution, movement and evolution of large water droplets in precipitation or clouds in the atmosphere and understand the structure and characteristics of weather systems. Rain radar can detect typhoons, local strong storms, hail, heavy rain and strong convective clouds, and can monitor weather changes.

wind detecting radar

It is used to detect the horizontal wind direction, wind speed and meteorological elements such as pressure, temperature and humidity in different atmospheres at high altitude. The detection method of wind radar is generally to track the reflection target or transponder hanging on the balloon and continuously locate the balloon. According to the displacement of the balloon in unit time, the horizontal wind direction and wind speed of different atmospheres can be determined. At the same time, a radiosonde is hung on the balloon to measure the air pressure, temperature and humidity at high altitude.

Circularly polarized radar

Generally, weather radar emits horizontally polarized waves or vertically polarized waves, while circularly polarized radar emits circularly polarized waves. When radar emits circularly polarized waves, the echo of spherical raindrops will be circularly polarized waves rotating in the opposite direction, while non-spherical large particles (such as hail) will depolarize the circularly polarized waves. Based on the echo characteristics of non-spherical hail depolarization, circular polarization radar can be used to identify whether there is hail in the storm.

Frequency modulated continuous wave radar

It is a radar for detecting the boundary layer atmosphere. It has extremely high range resolution and sensitivity, and is mainly used to measure the fluctuation, wind and turbulence of the clear atmosphere in the boundary layer (see atmospheric boundary layer).