The Radiation Laboratory, commonly called the Rad Lab, was located at the Massachusetts Institute of Technology (MIT) in Cambridge, Massachusetts (US) and functioned from October 1940 until December 31, 1945. Alfred Lee Loomis, a millionaire and physicist who headed his own private laboratory, selected the location for the laboratory on the campus, named it the MIT Radiation Laboratory, and arranged funding for the Rad Lab until federal money was allocated. It was formed by, and initially operated under, the National Defense Research Committee (NDRC), a commission established by U.S. President Franklin D. Roosevelt with Vannevar Bush as its chairman. In 1941, the NDRC was enlarged to become the Office of Scientific Research and Development (OSRD), with Bush remaining as chairman. Lee A. DuBridge served as the Rad Lab director. This facility was responsible for developing most of the microwave radars used by the United States during World War II, including the H2X radar used for bomb-aiming and the subsequent improvements to the initial H2X radar's technology.
The Rad Lab also developed Loran-A, the first worldwide radio navigation system, which originally was known as "LRN" for Loomis Radio Navigation, after Alfred Lee Loomis, who invented it and played a crucial role in military research and development during World War II. It remained the most widely used long-range navigation system until it was gradually replaced by Loran-C. Loran-A was discontinued by the United States in 1980.
During the mid- and late-1930s, radio systems for the detection and location of distant targets had been developed under great secrecy in the United States and Great Britain, as well as in several other nations, notably Germany, the USSR, and Japan. These usually operated at Very High Frequency (VHF) wavelengths in the electromagnetic spectrum and carried several cover names, such as Ranging and Direction Finding (RDF) in Great Britain. In 1941, the U. S. Navy coined the acronym 'RADAR' (RAdio Detection And Ranging) for such systems; this soon led to the name 'radar' and spread to other countries.