History of Radars

In 1886, German physicist Heinrich Hertz demonstrated that radio waves could be reflected by solid objects. In 1895, Alexander Popov, a professor of physics at the Russian Imperial Navy School in Kronstadt, developed a device that uses a coherent tube to detect distant lightning. Next year, he added a spark transmitter. In 1897, when tests of communications equipment between ships in the Baltic Sea, observed a jamming interference generated by the passage of a third ship. In his report, Popov wrote that this phenomenon could be used to detect objects, but did nothing more with this observation.
The German inventor Christian Hülsmeyer was the first to use radio waves to detect “the presence of metallic objects away.” In 1904 the viability of the detection of a ship in case of dense fog was demonstrated, but not its distance from the transmitter. It received a patent for its detection device in April 1904 and later a patent [9] for a corresponding modification of the estimate of the distance to the ship. He also received a British patent September 23, 1904 for a complete radar system, which he called a télémobiloscope. It was operated at a wavelength of 50 cm and the pulse radar signal was created by a spark gap. His system was already using the conventional antenna configuration of the parabolic reflector horn antenna and was presented to the German military authorities on field tests at the port of Rotterdam and Cologne, but was rejected.
In 1922, A. Hoyt Taylor and Leo C. Young, researchers working with the United States Navy, had a transmitter and receiver on the opposite sides of the Potomac River and found a ship passing through the Ray fused the signal received and out. Taylor reported, suggesting that this could be used to detect the presence of low visibility vessels, but the Navy did not immediately continue the work. Eight years later, Lawrence A. Hyland, the Naval Research Laboratory, observed bleaching effects similar to those of an aircraft pass; This led to a patent application and a serious work proposal for the NRL (Taylor and Young were then in the laboratory) on mobile target radio echo signals.
During the 1920s, the British research institution made many advances using radio techniques, including studying the ionosphere and detecting lightning over long distances. Robert Watson-Watt became an expert in the use of the find in the context of his lightning experiments. Under current experiments, he asked the “new guy” Frederic Arnold Wilkins, to find a receiver suitable for use with shortwave transmissions. Wilkins did a thorough study of the available units before choosing a receiver model from the General Post Office. Its instruction manual indicates that there was a “fainting” (the common term for interference at the time) when the aircraft was flying.
Before the Second World War, researchers in France, Germany, Italy, Japan, the Netherlands, the Soviet Union, the United Kingdom and the United States have developed technologies that led to the modern version of radar. Australia, Canada, New Zealand and South Africa followed Britain before the war, and Hungary have been a similar evolution in the war.