Barrage jamming: jamming accomplished by transmitting a band of frequencies that is large with respect to the bandwidth of a single emitter. Barrage jamming may be accomplished by presetting multiple jammers on adjacent frequencies, by using a single wideband transmitter, or by using a transmitter capable of frequency sweep fast enough to appear radiating simultaneously over wide band (e.g. a carcinotron). Barrage jamming makes it possible to jam emitters on different frequencies simultaneously and reduces the need for operator assistance or complex control equipment. These advantages are gained at the expense of reduced jamming power at any given frequency. Barrage jamming has to be used against frequency-agile radars, which change frequencies too quickly to follow them in a conventional way. The use of Barrage jamming may also affect the communications capability of the jamming source in a negative fashion.
Photomultiplier tubes were popularized during World War II since they could be used to as high bandwidth (up to several hundred MHz) noise sources. Although wide bandwidth sources typically suffer from low spectral power per unit frequency, the photomultiplier tube offers high gain (about ) amplification of photon shot noise, making it advantageous over other lower gain noise sources.
Famous quotes containing the word barrage:
“The rising power of the United States in world affairs ... requires, not a more compliant press, but a relentless barrage of facts and criticism.... Our job in this age, as I see it, is not to serve as cheerleaders for our side in the present world struggle but to help the largest possible number of people to see the realities of the changing and convulsive world in which American policy must operate.”
—James Reston (b. 1909)