What does a radar station do?

Where there are large radars

Radar emits electromagnetic energy into space in a directional manner. By receiving the radio waves reflected by objects in the space, it can calculate the The direction, height and speed of the object. It can also detect the shape of the object. The radar targeting the ground can detect the precise shape of the ground.

In 1922, Taylor and Young of the United States proposed equipping two warships with high-frequency transmitters and receivers to search for enemy ships. In 1924, Appleton and Barnett in England measured the height of the ionosphere by reflecting radio waves. Blair and Duff in the United States used pulse waves to measure the Heaviside layer. In 1931, the U.S. Naval Research Laboratory developed radar using the beat frequency principle and began to use the transmitter to emit continuous waves. Three years later, it switched to pulse waves. In 1935, French Guton developed a radar that uses a magnetron to generate a 16 cm wavelength. , other ships can be spotted in foggy weather or dark night. This was the beginning of the peaceful use of radar. In January 1936, the British W. Watt set up the first radar station in the UK on the coast of Sofke. The British Air Force added five more, which played an important role in World War II. In 1937, the first U.S. warship radar, the XAF, was successfully tested. In 1941, the Soviet Union was the first to equip aircraft with early warning radar. In 1943, the Massachusetts Institute of Technology in the United States developed an airborne radar plane position indicator that could photograph moving aircraft. He also invented a microwave early warning radar that could distinguish dozens of targets at the same time. In 1947, Bell Telephone Laboratories in the United States developed chirp pulse radar. In the mid-1950s, the United States was equipped with an over-the-range early warning radar system that could detect supersonic aircraft. Pulse Doppler radar was soon developed. In 1959, the American General Electric Company developed a ballistic missile early warning radar system that could track missiles 3,000 miles away and 600 miles high, with an early warning time of 20 minutes. In 1964, the United States installed the first space orbit surveillance radar, which was used to monitor artificial earth satellites or space vehicles. In 1971, Canadian Ijuka and three other people invented the holographic matrix radar. At the same time, digital radar technology emerged in the United States.