Radar Is Developed

The development of radar, which made the identification of distant objects possible, revolutionized both wartime and peacetime industries.

Summary of Event

“Radar” is an acronym for “radio detection and ranging.” The principle of radar involves the transmission of high-frequency pulses of electromagnetic energy through a directional antenna. The pulses are reflected by objects that intercept them. Radar receivers pick up the reflections, process them electronically, and convert them into dots of light (blips) on the face of a fluorescent screen that forms part of a cathode-ray tube. In this way, the receivers determine with instant precision the direction, distance, velocity, altitude, and even form of the targeted object, such as an airplane, ship, submarine, iceberg, body in space, thunderstorm, or landmass. [kw]Radar Is Developed (1934-1945)
[g]Europe;1934-1945: Radar Is Developed[08580]
[g]United States;1934-1945: Radar Is Developed[08580]
[c]Science and technology;1934-1945: Radar Is Developed[08580]
[c]Military history;1934-1945: Radar Is Developed[08580]
[c]Inventions;1934-1945: Radar Is Developed[08580]
Hülsmeyer, Christian
Page, Robert M.
Young, Leo C.
Watson-Watt, Robert Alexander
Tizard, Henry Thomas

Three U.S. soldiers sit in place at a radar installation used in Casablanca, French Morocco, during World War II.


Radar came into widespread use during World War II World War II (1939-1945)[World War 02];radar and has been credited with changing the course of history, and certainly that of North American history. During the 1930’s, radar development was pioneered independently and simultaneously in Britain, France, Germany, and the United States. While several proposals to build radar-type detection devices had been made since the late nineteenth century—including a demonstration by Germany’s Christian Hülsmeyer in 1904—it was not until the 1930’s that the study of radio-echo signals from moving objects was considered important. Early in 1934, Robert M. Page, an American physicist pursuing the theory of his colleague Leo C. Young at the U.S. Naval Research Laboratory, worked out a practical technology for pulse radar. This development marked the beginning of an effective radar program in the United States.

By this time, Britain was becoming increasingly apprehensive of Adolf Hitler’s rearming of Nazi Germany. Responding to rumors about a German “death ray” initiated by a speech by the Nazi leader, Scottish physicist Robert Alexander Watson-Watt wrote a report in which he demolished the death-ray fiction but observed that the echoes of shortwave pulses could be used to locate approaching aircraft and the like. To boost the British effort, a special committee headed by scientist Henry Thomas Tizard was formed to give top priority to the systematic research and development of British radar. By 1935, Watson-Watt had completed a practical radar system that was to contribute to the successful outcome of the Battle of Britain Britain, Battle of (1940);radar five years later. Simultaneously, the French were placing their own version of radar on the luxury liner Normandie to assist in the detection of icebergs on crossings of the North Atlantic.

Thus, by the beginning of World War II, several nations benefited from functioning radar systems. These systems were based on fundamentally different designs. The further diversification of radar designs and their applications by the Allies and Germany would improve the technology considerably by the end of the war. The British won the Battle of Britain by using radar to help intercept approaching aircraft. When Germany switched to night bombing in 1941, British ground and airborne radar enabled British fighters to zero in on the attackers. The German threat of invasion was thus foiled, and Britain in turn became the strategic staging area from which the Allied forces launched their landing in Nazi-held “fortress Europe” in 1944.


In some respects, radar was a typical product of mid-twentieth century scientific technology. It was made possible by an earlier effort, a research project committed solely to an understanding of pertinent scientific phenomena. Two names stand out in this connection: James Clerk Maxwell Maxwell, James Clerk in Britain, whose mathematical predictions in 1864 regarding the nature of light and electromagnetic phenomena indicated that the latter, like the former, could be reflected, and Heinrich Hertz, Hertz, Heinrich a German physicist who in 1887 demonstrated that Maxwell was right. Hertz’s efforts were based on the sophisticated understanding of electronics that had formed over three decades of experiments with radio communications. So many individuals were involved in this development that it can be said that radar—like most scientific breakthroughs—evolved rather than was invented.

The fact that radar did not have any single inventor was also a result of its complexity, its design variations, and the number of different components used in radar systems. Moreover, the national emergency of war mandated a total mobilization of resources on the parts of all involved. Accordingly, for perhaps the first time in history, scientists, policy makers, military personnel, and others on both sides of the Atlantic became completely devoted to research and development on a single project. In tribute, former World War II German navy head Admiral Karl Doenitz said in 1945, “The one single weapon which defeated the [German] submarine and the Third Reich was the long-range airplane with radar.” In subsequent years, scientists were to focus on technologies that enabled aircraft to avoid radar detection, radar contact with planets and other celestial bodies (radio astronomy), and the use of radar to improve the safety of air travel. Radar

Further Reading

  • Bowen, E. G. Radar Days. Bristol, England: Adam Hilger, 1987. Describes how airborne radar helped to defeat Hitler and the bombers of the Luftwaffe. Early accounts of English radar usually were written from the viewpoint of someone in the higher echelons of government or as seen by the management, but this work was written from the point of view of those who performed laboratory studies, which were followed by flight trials in which the lone experimenter tried to simulate the problems likely to be met in upcoming battles.
  • Brown, L. A Radar History of World War II: Technical and Military Imperatives. Boca Raton, Fla.: Taylor & Francis, 1999. Comprehensive volume discusses radar programs in every nation that participated in World War II.
  • Buderi, Robert. The Invention That Changed the World: How a Small Group of Radar Pioneers Won the Second World War and Launched a Technical Revolution. Carmichael, Calif.: Touchstone Books, 1998. Provides a clear and logical explanation of the technology behind radar and its development. Includes several short biographies of the individuals involved.
  • Burns, Russell W., ed. Radar Development to 1945. London: Peregrinus, 1988. Illustrated, blow-by-blow account of the development of radar in various countries. Among those writing the history of American radar is one of its principal developers, Dr. Robert M. Page, the retired head of the U.S. Naval Research Laboratory.
  • Clark, Ronald W. Tizard. Cambridge, Mass.: MIT Press, 1965. In 1940, the Tizard mission was sent to the United States to disclose English secret technical advances, including radar, in return for U.S. help on technical and production matters. No comprehensive account of the Tizard mission has ever been written, but this book is a step in that direction.
  • De Arcangelis, Mario. Electronic Warfare: From the Battle of Tsushima to the Falklands and Lebanon Conflicts. Poole, England: Blandford Press, 1985. Fascinating, clearly written account of important military operations involving radar and other technologies.
  • Fisher, David E. A Race on the Edge of Time: Radar, the Decisive Weapon of World War II. New York: McGraw-Hill, 1988. Competent account of radar’s use during the war. Based on interviews with those involved.
  • Pritchard, David. The Radar War: Germany’s Pioneering Achievement, 1904-1945. Wellingborough, England: P. Stephens, 1989. Traces the development of German radar from Hülsmeyer’s demonstration to the end of the war. Includes photographs of individuals and equipment.
  • Rowe, Albert P. One Story of Radar. Cambridge, England: Cambridge University Press, 1948. The period at St. Athan will be remembered for the start of mass production of airborne radar and for fitting these sets to aircraft at an unprecedented rate. As that work drew to a close, another move was contemplated. The decision of where to relocate was decided by events at Dundee, where things had reached crisis point. The fiction that Dundee was a good place for radar research could no longer be maintained and another move had to be made.
  • Skolnik, Merrill I. Introduction to Radar Systems. 2d ed. New York: McGraw-Hill, 1980. Includes a few pages devoted to radar development prior to World War II. Surveys the efforts of both Allied and Axis powers.
  • Watson-Watt, Robert A. The Pulse of Radar: The Autobiography of Sir Robert Watson-Watt. New York: Dial Press, 1959. Account by the gifted Scottish pioneer of radar, including a perceptive chapter on why the Americans ignored radar warnings of the impending Japanese attack at Pearl Harbor on December 7, 1941.

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