noise jammer

noise jammer

[′nȯiz ‚jam·ər]
(electronics)
An electronic jammer that emits a carrier modulated with recordings or synthetic reproductions of natural atmospheric noise; the radio-frequency carrier may be suppressed; used to discourage the enemy by simulating naturally adverse communications conditions.
During World War II, a powerful transmitter modulated with white noise tuned to the approximate frequency of an enemy transmitter and used to obscure intelligible output at the receiver.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
References in periodicals archive ?
One way to take advantage of the noise jammer's simplicity, but raise the jamming signal power, is to use a spot jammer.
Hence, the probability of error depends on the number of users (N), spreading factor (2[beta]), estimated channel coefficients ([Mathematical expression not reproducible.]), the signal to noise ratio ([E.sub.b]/[N.sub.0]), duty cycle of pulse noise jammer ([rho]), signal to jamming power ratio ([E.sup.b]/[P.sup.j]), and number of receiving antennas (M).
However, indiscriminate use of a noise jammer is not only a waste of costly jamming resources, but may actually compromise the safety of the jamming platform.
However, indiscriminate use of a noise jammer may not only be wasteful of costly jamming resources, but may actually compromise the safety of the jamming platform.
Under typical receiver-track-mode operation, an 8-watt wideband noise jammer will deny GPS reception for up to 40 kin.
The variations in PRF and frequency required the noise jammer to spread its power across multiple frequencies and PRFs or to track the threat radar's changes.
In addition to the self-protection system already mentioned, the family includes a noise jammer to counter radars in the 10-, 20- and 70-cm wavelengths.
Further, the preset threshold has no capability to ignore external noise, as might be received from a noise jammer. The preset threshold does, however, have the advantage of providing an essentially instantaneous threshold setting following a receiver band change.
Key modules in the early 1980s appear to have been the ELT/211 surface-ship ESM, the ELT/318 multimode noise jammer and the ELT/521 multimode deception jammer.
Wide tuning bandwidth: The wide tuning bandwidth combined with rapid changes in frequency may force the noise jammer out of the spot noise mode and into the barrage noise mode, which has proportionally less power density.
Airborne systems include the 1- to 18-GHz BM/KZ 8608 ELINT system, the GT-1 chaff/IR decoy flare dispenser, the 0.7- to 1.4-GHz/2- to 18-GHz BM/KJ 8502 fixed-wing RWR, the BM/KG 8601 E/F- and I/J-band repeater jammer, the BM/KG 8606 I-band radar jammer, the BM/KG 8605 I/J-band noise jammer and the BM/KG 8605 I-band radar jammer.
The science of electronic countermeasures can trace its roots to the simple broadbeam, broadband, noise jammer, which was an extremely effective system until radar designers developed techniques to counter that type of jamming.