The Doppler Effect was proposed by Christian Doppler in Prague. It is a phenomenon used to measure the velocity of detected objects. This effect has been utilized in various radar systems and continues to be employed.

The first discoveries related to radar technology were made during this time period.

In 1888, German physicist Heinrich Hertz demonstrated the properties of radio waves, including reflection from metallic objects and refraction by dielectric medium, using radio waves at a wavelength of 66 cm.

In 1895, Alexander Stepanovich Popov developed a radio communication set in Russia using a coherer tube and a spark-gap transmitter. This laid the foundation for early radio technology.

In March 1899, radio pioneer Guglielmo Marconi conducted radio beacon experiments on Salisbury Plain, where he observed radio waves being reflected back to the transmitter by objects. This discovery was crucial for the practical development of radar, especially when he utilized short-waves in 1916 experiments.

Christian Hülsmeyer invented radar in 1904 by developing a device called the telemobiloscope, which could measure the transit time of reflected waves, allowing the detection of distant metallic objects.

On March 11, 1915, Robert Watson-Watt, a Scottish physicist and meteorologist, was born. He is known for his significant contributions to the development of radar technology.

In 1922, Hulsmeyer was granted a patent in multiple countries for a proposed method that involved using electromagnetic waves as an obstacle detector and navigation aid for ships. This innovation laid the foundation for radar technology.

In 1927, French physicists Camille Gutton and Emile Pierret experimented with magnetrons and devices generating wavelengths going down to 16 cm. This experimentation laid the foundation for further developments in radar technology.

Lawrence A. Hyland, along with Taylor and Young, used radio equipment to detect passing aircraft in 1930, which eventually led to the proposal and patent for using radar technology for detecting ships and aircraft.

Starting in 1931, Pierre David at the Laboratoire National de Radioélectricité experimented with reflected radio signals at about a meter wavelength, leading to research on a detection technique called barrage électromagnétique.

In June 1933, physicist Pavel K. Oshchepkov shifted his research focus from optics to radio techniques, leading to the development of a reconnaissance electromagnetic station. This marked the beginning of radio-location techniques in the Soviet Union.

Lt. Gen. M. M. Lobanov, in charge of the aircraft detection problem at the Glavnoe Artilleriyskoe Upravlenie (GAU), collaborated with Yu. K. Korovin from the Tsentral’naya Radiolaboratoriya (TsRL) in Leningrad. They successfully received a Doppler signal from an aircraft at 600m range and 100-150m altitude using a 50 cm transmitter on January 3, 1934.

On June 17, 1935, the first target, a Supermarine Scapa flying boat, was detected using radio-based detection and ranging at a range of 17 miles. This event is historically significant as it marks the first demonstration of radar in Britain.

On December 14, 1936, the Signal Corps Laboratories successfully detected aircraft at a range of up to 7 miles using pulsed microwave transmission technology.

On May 26, 1937, the first demonstration of a radar system took place where a bomber was detected and illuminated by a searchlight. This event impressed the Secretary of War, leading to orders for the full development of the system.

At the start of 1938, the Royal Air Force (RAF) took over control of all Chain Home (CH) stations, marking the beginning of regular operations for the network.

In April 1938, an 'electrical listening device' operating at 70 cm (430 MHz) was demonstrated to the Army. The device detected an aircraft at a range of 18 km (11 mi) but was rejected due to its inability to withstand harsh combat conditions.

In May 1938, Rowe replaced Watson Watt as Superintendent at Bawdsey, overseeing work on Chain Home (CH) and successor systems, as well as major work in airborne RDF equipment.

In July 1938, the Redut radar system was developed by Ioffe's LPTI, featuring a peak power of 50 kW and 10 μs pulse duration. It was tested in October 1939 near Sevastopol, Ukraine, detecting aircraft at ranges up to 150 km.

In August 1938, the RUS-1 radar system was developed as a mobile system called Radio Ulavlivatel Samoletov (RUS). It featured a truck-mounted transmitter operating at 64 MHz and two truck-mounted receivers for aircraft detection.

In October 1938, Pierre David designed a 50 MHz, pulse-modulated system with a peak-pulse power of 12 kW, realizing the advantages of a pulsed system for aircraft detection.

Arnold Wilkins, along with Robert Watson-Watt, suggested the use of reflected radio waves to detect aircraft, leading to the first ground to air radar detection.

In mid-1940, Maurice Ponte presented a cavity magnetron designed by Henri Gutton at SFR to the GEC laboratories at Wembley, Britain, marking a significant contribution to British radar.

On August 2, 1941, funds were allocated for the initial development of pulse-modulated radars in Japan, following reports from technical exchanges with Germany and intelligence concerning Britain's success with RDF.

On December 7, 1941, a radar system detected a flight of aircraft approaching Pearl Harbor, but the warning was misidentified as U.S. bombers. This led to the devastating attack by Japanese aircraft on Pearl Harbor.

Australia received the first Japanese attack on February 19, 1942, while the air-warning system, AW Mark I, was being installed in Darwin.

In December 1945, the Jodrell Bank Observatory, initially established as a radar astronomy facility by Bernard Lovell, made its first observations of ionized trails in the Geminids meteor shower.

Under Project Diana, radar echoes from the Moon were received using a modified SCR-271 radar operating at 110 MHz with 3 kW peak-power on January 10, 1946. Zoltán Bay accomplished this on February 6, 1946.

In the early 1950s, a team at the Naval Research Laboratory developed the Over-the-Horizon (OTH) radar to provide early warnings at great ranges for long-range bombers and missiles.

In 1951, Carl Wiley led a team at Goodyear Aircraft Corporation in developing synthetic aperture radar (SAR), a technique that greatly improved radar-generated image resolution by using complex signal processing with an ordinary-sized antenna fixed to an aircraft.

In 1953, the RAF's Telecommunications Research Establishment and the Army's Radar Research and Development Establishment were combined to form the Radar Research Establishment in Britain.

The radar gun, a handheld Doppler radar device used to detect the speed of objects like vehicles and baseballs, was first developed in 1954. It operates with low power in X or Ku Bands and is widely used in traffic regulation and sports.

In 1955, Bryce Brown, a university professor with experience from the Manhattan Project, established Muniquip (short for Municipal Equipment) where he started manufacturing the first law enforcement radar using speed timers made from stretching two hoses across a road.

John Randall created a device called cavity magnetron that generates microwaves using electrons in a magnetic field.

The WSR-57 was an 'S' band radar system developed for the United States Weather Bureau and the U.S. Navy. It has been in service since 1959 and continues to be a significant part of the National Weather Service's radar network.

In 1960, it became mandatory for aircraft flying in certain areas to carry radar transponders to improve radar performance and aid in aircraft identification. This requirement aimed to enhance air traffic control systems.

The Arecibo Observatory, opened in 1963, was the largest radio telescope in the world. It was primarily used for radio astronomy but also had equipment available for radar astronomy, making significant scientific discoveries.

In 1964, Bryce Brown left Millikin University to focus on his radar company. He later sold his other products to a Toronto firm, retaining the radar division and renaming the company to Decatur Electronics, Inc.

Since 1966, the responsible agency for air traffic control in the United States has been the Federal Aviation Administration (FAA). The FAA oversees various aspects of aviation safety and regulation.

In 1970, the book 'Radar Meteorology' by H.W. Hiser was published, providing valuable insights and information on the use of radar in meteorology.

In May 1973, a tornado in Union City, Oklahoma, was documented by a Dopplerized 10-cm wavelength radar from NSSL, revealing a mesoscale rotation in the cloud aloft before the tornado touched the ground.

In 1974, the National Weather Service and the U.S. Air Force initiated the procurement and setup of the WSR-74 'C' band system, known as FPQ-21 in military terms.

A Safeguard site near Grand Forks AFB in North Dakota, intended to defend Minuteman ICBM missile silos, was completed in October 1975. However, funding was withdrawn by the U.S. Congress after just one day of operation.

In 1976, the Soviet Union successfully developed the Duga OTH radar system, also known as Steel Yard, which was capable of detecting missile launches at long distances. Western intelligence referred to it as Woodpecker due to interference issues caused by its powerful 10 MW transmitter.

In 1977, the Weather Surveillance Radar-57 (WSR-57) was implemented, which shot bursts of energy from a rotating antenna to gauge the size of particles like rain, snow, or hail, enhancing weather monitoring capabilities.

A technical history of the beginnings of radar technology by Seán S. Swords.

In 1988, the construction of a network consisting of 10 cm (4 in) wavelength radars, called NEXRAD or WSR-88D, started in the United States following NSSL's research on Doppler radar.

In 1989, the Arecibo Observatory radar-imaged an asteroid for the first time in history, marking a significant milestone in radar astronomy.

A historical account of the history of H2S radar by Sir Bernard Lovel.

In 1992, the Next-Generation Radar systems (NEXRAD) were introduced, utilizing Doppler technology to detect the movement of particles, precipitation, and wind inside storms, providing crucial information for meteorologists and the public.

In 1993, McGill University dopplerized its radar (J. S. Marshall Radar Observatory), contributing to the development of the Canadian Doppler network.

The Bismarck WSR-88D radar was installed in 1994, enhancing weather monitoring capabilities in the region with improved resolution and severe weather detection.

A history of radar in the UK during WWII told by the men and women who worked on it.

A book about night fighters, possibly related to radar technology.

A book detailing the birthplace of German radar and sonar, translated by Louis Brown.

A book detailing Britain's radar technology and its role in the defeat of the Luftwaffe.

Since 2003, the U.S. National Oceanic and Atmospheric Administration has been experimenting with phased-array radar as a replacement for conventional parabolic antenna to provide more time resolution in atmospheric sounding.

Memoirs detailing the birth of British radar by Arnold 'Skip' Wilkins.

A comprehensive history of radar evolution in 13 nations during World War II by Raymond C. Watson, Jr.

Radar technology has evolved to be utilized in various applications such as detecting speed with radar guns, monitoring weather patterns, and in military operations.

Due to cable failures, the Arecibo Observatory telescope suffered a collapse on December 1, 2020, leading to the decision of decommissioning the telescope through controlled demolition.

The history of radar involves a long line of innovation by both military and civilian inventors. It has been crucial in various fields including law enforcement.

Fraunhofer FHR showcased a project focusing on Automotive Radar technology. This project aimed to demonstrate the capabilities and advancements in radar technology for automotive applications.