Bhangmeter

A bhangmeter is a non-imaging radiometer installed on reconnaissance and navigation satellites to detect atmospheric nuclear detonations and determine the yield of the nuclear weapon.

The bhangmeter was invented, and the first proof-of-concept device was built, in 1948 to measure the nuclear test detonations of Operation Sandstone. Prototype and production instruments were later built by EG&G, and the name “bhangmeter” was coined in 1950. Bhangmeters became standard instruments used to observe US nuclear tests. A Mod II bhangmeter was developed to observe the detonations of Operation Buster-Jangle (1951) and Operation Tumbler-Snapper (1952). These tests lay the groundwork for a large deployment of nationwide North American bhangmeters with the Bomb Alarm System (1961-1967).

US president John F. Kennedy and the First Secretary of the Communist Party of the Soviet Union Nikita Khrushchev signed the Partial Test Ban Treaty on August 5, 1963, under the condition that each party could use its own technical means to monitor the ban on nuclear testing in the atmosphere or in outer space.

Bhangmeters were first installed, in 1961, aboard a modified US KC-135A aircraft monitoring the pre-announced Soviet test of Tsar Bomba.

The Vela satellites were the first space-based observation devices jointly developed by the U.S. Air Force and the Atomic Energy Commission. The first generation of Vela satellites were not equipped with bhangmeters but with X-ray sensors to detect the intense single pulse of X-rays produced by a nuclear explosion. The first satellites which incorporated bhangmeters were the Advanced Vela satellites.

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Wikipedia