History of Radar in Timeline

Radar is a radiodetermination system employing radio waves to ascertain an object's range, direction, and radial velocity relative to the radar's location. Its applications span detecting and tracking various objects, including aircraft, ships, vehicles, weather patterns, and terrain. Coined in 1940 by the U.S. Navy as an acronym for "radio detection and ranging," the term 'radar' has evolved into a common noun, losing its capitalization. It is a crucial technology for navigation, surveillance, and meteorology.

April 1904: Christian Hülsmeyer Patents Detection Device

In April 1904, Christian Hülsmeyer obtained a patent for his detection device, which used radio waves to detect the presence of distant metallic objects. He later obtained a patent amendment for estimating the distance to the ship.

September 1904: British Patent for Telemobiloscope

On September 23, 1904, Christian Hülsmeyer obtained a British patent for a full radar system called a telemobiloscope. It used a 50 cm wavelength and a spark-gap to create the pulsed radar signal. The system used a horn antenna with a parabolic reflector, but it was rejected by German military officials.

1915: Robert Watson-Watt Used Radio Technology to Detect Thunderstorms

In 1915, Robert Watson-Watt used radio technology to provide advance warning of thunderstorms to airmen.

1922: U.S. Navy Researchers Discover Signal Fading Due to Ships

In 1922, U.S. Navy researchers A. Hoyt Taylor and Leo C. Young discovered that ships passing through the beam path between a transmitter and receiver caused the received signal to fade in and out. Taylor suggested using this to detect ships in low visibility.

1928: Secret Provisional Patent for Naval Radar

In 1928, L. S. Alder took out a secret provisional patent for Naval radar in the UK.

January 1931: First Official Record of Coastal Defence Technology

In January 1931, a writeup on the apparatus developed by W.A.S. Butement and P. E. Pollard was entered in the Inventions Book maintained by the Royal Engineers. This is the first official record in Great Britain of the technology that was used in coastal defence and was incorporated into Chain Home as Chain Home (low). The apparatus operated at 50 cm (600 MHz) and used pulsed modulation.

December 1934: First Pulsed System Demonstrated

In December 1934, Robert M. Page at the Naval Research Laboratory demonstrated the first elementary pulsed radar apparatus.

1934: CSF Begins Developing Obstacle-Locating Radio Apparatus

In 1934, the research branch of the Compagnie générale de la télégraphie sans fil (CSF), headed by Maurice Ponte, began developing an obstacle-locating radio apparatus following systematic studies on the split-anode magnetron.

February 1935: The Daventry Experiment

On February 26, 1935, the Daventry Experiment was performed using a powerful BBC shortwave transmitter as the source and their GPO receiver setup in a field while a bomber flew around the site. When the plane was clearly detected, Hugh Dowding was impressed with their system's potential and funds were provided for further operational development.

May 1935: Germany Tests Surface-to-Surface Radar

In May 1935, the United States Army successfully tested a primitive surface-to-surface radar to aim coastal battery searchlights at night. This design was followed by a pulsed system demonstrated by Rudolf Kühnhold and the firm GEMA in Germany.

June 1935: Air Ministry Team Demonstrates Pulsed System

In June 1935, an Air Ministry team led by Robert Watson-Watt in Great Britain demonstrated a pulsed radar system.

1935: Radar Aspects Installed on Ocean Liner Normandie

In 1935, aspects of the obstacle-locating radio apparatus developed by CSF were installed on the ocean liner Normandie.

1935: Working Radar Systems Produced

In 1935, the team produced working radar systems and began deployment of the Chain Home (CH) system.

1936: First Five Chain Home Systems Operational

By 1936, the first five Chain Home (CH) systems were operational.

1936: Watson-Watt Becomes Superintendent of Bawdsey Research Station

In 1936, Robert Watson-Watt became superintendent of a new establishment under the British Air Ministry, Bawdsey Research Station, leading to the design and installation of Chain Home aircraft detection stations.

1938: First Commercial Radar Device Fitted to Aircraft

In 1938, the first commercial radar device fitted to aircraft was a Bell Lab unit on some United Air Lines aircraft.

1939: Chain Home Operational at Outbreak of WWII

By the outbreak of World War II in 1939, the Chain Home system of aircraft detection and tracking stations was installed along the East and South coasts of England. This system provided vital advance information that helped the Royal Air Force win the Battle of Britain.

1939: Soviets Produced First Mass Production Radars RUS-1 and RUS-2 Redut

In 1939, the Soviets produced their first mass production radars, the RUS-1 and RUS-2 Redut. However, further development was slowed following the arrest of P.K. Oshchepkov, who was collaborating with the Leningrad Electrotechnical Institute.

April 1940: Popular Science Shows Radar Unit Using Watson-Watt Patent

In April 1940, Popular Science showed an example of a radar unit using the Watson-Watt patent in an article on air defense.

1940: Chain Home Stretched Across the Entire UK

By 1940, the Chain Home (CH) systems stretched across the entire UK, including Northern Ireland.

1940: Cavity Magnetron Key Development

In 1940, a key development was the cavity magnetron in the UK, which allowed the creation of relatively small systems with sub-meter resolution. Britain shared the technology with the U.S. during the Tizard Mission.

1940: Term RADAR coined

In 1940, the United States Navy coined the term RADAR as an acronym for "radio detection and ranging." Since then, the term radar has entered English and other languages as an anacronym and a common noun, losing all capitalization.

1941: Watson-Watt Advises on Air Defense; MIT Radiation Laboratory Organized

In 1941, Watson-Watt was sent to the U.S. to advise on air defense after Japan's attack on Pearl Harbor. Also in 1941, Alfred Lee Loomis organized the secret MIT Radiation Laboratory at Massachusetts Institute of Technology, Cambridge, Massachusetts which developed microwave radar technology in the years 1941–45.

June 1943: First Russian Airborne Radar Enters Service

In June 1943, the first Russian airborne radar, Gneiss-2, entered into service on Pe-2 dive bombers.

1943: Page Improves Radar with Monopulse Technique

In 1943, Robert M. Page greatly improved radar with the monopulse technique, which was used for many years in most radar applications.

1944: Production of Gneiss-2 Radar Stations

By the end of 1944, more than 230 Gneiss-2 radar stations had been produced.

1978: U.S. Navy Aircraft Loss Attributed to Coolanol Fire

In 1978, the loss of a U.S. Navy aircraft was attributed to a silicate ester (Coolanol) fire. Coolanol was used in several military radars but is hygroscopic and toxic.

2017: NOAA Plans National Network of Phased Array Radars

As of 2017, NOAA plans to implement a national network of multi-function phased array radars throughout the United States within 10 years, for meteorological studies and flight monitoring.