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In July 1962, the US carried out the Starfish Prime test, exploding a 1.44 Mt (6.0 PJ) bomb 400 kilometres (250 mi; 1,300,000 ft) above the mid-Pacific Ocean.This demonstrated that the effects of a high-altitude nuclear explosion were much larger than had been previously calculated.
An electromagnetic pulse (EMP), also referred to as a transient electromagnetic disturbance (TED), is a brief burst of electromagnetic energy. The origin of an EMP can be natural or artificial, and can occur as an electromagnetic field , as an electric field , as a magnetic field , or as a conducted electric current .
An electromagnetic pulse (EMP), sometimes called a transient disturbance, is a short-duration pulse of energy. This energy is usually broadband by nature, although it often excites a relatively narrow-band damped sine wave response in the victim. Pulse signals divide broadly into isolated and repetitive events.
The most notable of these is the Worked All Trinidad and Tobago Simplex or WATTS contest. The objective of this contest is to make contact with as many amateur radio operators in Trinidad and Tobago without the aid of repeater stations or satellites. The club station 9Y4TT is also active for some contests including the IARU HF championships.
EMP-like effects are not always from open-air or space explosions; there has been work with controlled explosions for generating electrical pulse to drive lasers and railguns. For example, in a program called BURNING LIGHT, KC-135R tankers, temporarily modified to carry MASINT sensors, would fly around the test area, as part of Operation ...
The pulse-repetition frequency (PRF) is the number of pulses of a repeating signal in a specific time unit. The term is used within a number of technical disciplines, notably radar . In radar, a radio signal of a particular carrier frequency is turned on and off; the term "frequency" refers to the carrier, while the PRF refers to the number of ...
A pulse per second (PPS or 1PPS) is an electrical signal that has a width of less than one second and a sharply rising or abruptly falling edge that accurately repeats once per second. PPS signals are output by radio beacons, frequency standards , other types of precision oscillators and some GPS receivers.
Pulse-frequency modulation (PFM) is a modulation method for representing an analog signal using only two levels (1 and 0). It is analogous to pulse-width modulation (PWM), in which the magnitude of an analog signal is encoded in the duty cycle of a square wave .