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With further advances, it became practical to generate pulses having a width on the same order as the period of the RF carrier (T = 1/f). This is now generally called impulse radar. The first significant application of this technology was in ground-penetrating radar (GPR). Developed in the 1970s, GPR is now used for structural foundation ...
Project Diana marked the birth of radar astronomy later used to map Venus and other nearby planets, and was a necessary precursor to the US space program. It was the first demonstration that terrestrial radio signals could penetrate the ionosphere, [1] opening the possibility of radio communications beyond the Earth for space probes and human ...
Radar coverage along the UK coast, 1939–1940. By 1937, the first three stations were ready, and the associated system was put to the test. The results were encouraging, and the government immediately commissioned construction of 17 additional stations. This became Chain Home, the array of fixed radar towers on the east and south coasts of ...
The radar mile is the time it takes for a radar pulse to travel one nautical mile, reflect off a target, and return to the radar antenna. Since a nautical mile is defined as 1,852 m, then dividing this distance by the speed of light (299,792,458 m/s), and then multiplying the result by 2 yields a result of 12.36 μs in duration.
After the United States entered World War I in 1917, Loomis volunteered for military service. He was commissioned as a captain, and rose to the rank of lieutenant colonel. He worked in ballistics at the Aberdeen Proving Ground in Maryland, where he invented the Aberdeen Chronograph, the first instrument to measure accurately the muzzle velocity of artillery shells, and portable enough to be ...
1911: The cloud chamber, the first particle detector, is invented by Charles Thomson Rees Wilson. 1912: The first commercial slot cars or more accurately model electric racing cars operating under constant power were made by Lionel (USA) and appeared in their catalogues in 1912. 1912: The first use of articulated trams by Boston Elevated Railway.
AZON (or Azon), from "azimuth only", was one of the world's first guided weapons, deployed by the Allies and contemporary with the German Fritz X.. Officially designated VB-1 ("Vertical Bomb 1"), it was invented by Major Henry J. Rand and Thomas J. O'Donnell during the latter stages of World War II as the answer to the difficult problem of destroying the narrow wooden bridges that supported ...
Sputnik 1 (/ ˈ s p ʌ t n ɪ k, ˈ s p ʊ t n ɪ k /, Russian: Спутник-1, Satellite 1), sometimes referred to as simply Sputnik, was the first artificial Earth satellite.It was launched into an elliptical low Earth orbit by the Soviet Union on 4 October 1957 as part of the Soviet space program.