Weather radar is used to measure and calculate precipitation. This type of radar is used all over the world in order to detect incoming weather. Modern weather radar is now quite advanced, though it wasn't always so precise. Thanks to a simple observation that occurred during World War II, weather can now be observed accurately.
World War II radar operators noticed that radar signals made a different sound when the weather was about to change. If rain, snow, sleet, or other precipitation occurred, returned radar noise was altered according to the type of precipitation that was in the air. Taking these weather observations with them after the war, former military radar operators began to experiment with various types of weather radar.
From 1950 to 1980, reflectivity radars were widely used amongst meteorologists. These radars were able to measure the positioning and strength of incoming precipitation, but they could not measure the velocity of air particles. Velocity was soon added to weather radar equipment when the Doppler radar system was invented.
Today, most meteorologists use Doppler radar to detect precipitation, though this for of radar is constantly being updated. Meteorologists can now differentiate between two types of precipitation that is seemingly similar. Thus, today's weather forecasts can accurately predict either rain or snow, though earlier radar systems could not separate the two forms of precipitation.
Weather radar systems have proved to be extremely useful when it comes to thunderstorm tracking. Modern technology allows meteorologists to track the intensity and severity of an incoming thunderstorm. This has allowed for large populations to move out of the way of a particularly treacherous storm.
Aside from tracking weather on the ground, commercial airlines also use weather radar to assist pilots with aircraft maneuvering. Since airplanes move in all directions, it helps pilots to know when and where weather is occurring. These radar detectors are attached to the nose of an airplane, and they help pilots keep an airplane headed in the right direction no matter what the present weather may be.
Most countries presently have national radar centers that detect the weather in and around a certain territory. Covering such a large expanse of land is somewhat difficult, though contemporary radar advancements make such a task possible. By combining information taken from numerous radars, national weather centers are able to determine weather that may affect various parts of a country, or the country as a whole.