The Illustrated Dictionary of Electronics - Loscha

ARSR • assemble 41ARSR Abbreviation of air route surveillance radar.articulation A measure of the effectiveness of voicecommunications, expressed as the percentage ofspeech units understood by the listener when theeffect of context is negligible.artificial antenna See DUMMY ANTENNA.artificial ear A microphone-type sensor, equivalentto the human ear, used to measure soundpressures.artificial echo 1. In radar practice, the reflectionsof a transmitted pulse returned by an artificialtarget. 2. A signal from a pulsed radio-frequency(RF) generator, delayed to simulate an echo.artificial ground The effective ground provided bythe radials or disk of a ground-plane antenna, asopposed to actual ground (the earth itself ). CompareTRUE GROUND.artificial horizon In aircraft instrumentation, adevice that displays lines showing the position ofthe aircraft in flight, with reference to the horizon.artificial intelligence Abbreviation, AI. 1. A specializedfield of computer science overlappingwith electronics, biology, physiology, and othersciences, concerning attempts to develop advancedcomputer systems that can emulate theprocesses of the human mind. 2. The ability of acomputer to learn from its mistakes, refine itsown processes, and perhaps ultimately reason ina humanlike manner.artificial ionization An artificial reflecting layerthat is created in the atmosphere to provide askip condition.artificial language A language that is not commonlyused, but has been devised for efficiency ina particular situation—especially in a computersystem.artificial life 1. The ultimate endpoint of ARTIFI-CIAL INTELLIGENCE, wherein machines acquirequalities, such as wisdom and the capability tofeel emotions. The state of the art is currentlynowhere near this point. 2. A hypothetical machineor set of machines with lifelike qualities, includinghuman-level intelligence, wisdom, andemotion.artificial stimulus An electronic method of robotguidance and navigation using radar, sonar, visionsystems, edge detection, and/or beacons.artificial transmission line A network of capacitorsand inductors with characteristics similar tothose of the more bulky transmission line it replacesin tests and measurements. It also servesas a time-delay or phase-shift device and as apulse-forming network.artificial voice A device used to test and calibratenoise-canceling microphones, consisting essentiallyof a small loudspeaker that has a bafflewhose acoustical properties simulate those of thehuman head.artos stripper A machine that cuts and strips wirefor the fabrication of multiconductor cables.artwork 1. In the manufacture of printed circuits,the scaled drawings from which the mask or etchpattern is obtained photographically. 2. Collectively,the illustrations depicting an electronic circuit,device, or system.As Symbol for ARSENIC.ASA Abbreviation of AMERICAN STANDARDS AS-SOCIATION.asbestos A nonflammable fibrous material consistingof calcium and magnesium silicates that isused for high-temperature insulation.A-scan A radar-screen presentation in which thehorizontal time axis displays distance or range,and the vertical axis displays the amplitude ofsignal pulse and echo pulses.ascending node For a satellite orbiting the earth oranother planet, any point at which the groundtrackcrosses the equator as it moves from thesouthern hemisphere into the northern hemisphere.This node generally changes for eachsucceeding orbit, because the earth or planet rotatesunderneath the orbit of the satellite. CompareDESCENDING NODE.ascending pass For a specific point on the earth’ssurface, the time during which an artificial communicationssatellite is accessible when its latitudeis moving northward. The duration ofaccessibility depends on the altitude of the satellite,and on how close its groundtrack comes tothe earth-based point. Compare DESCENDINGPASS.ASCII Acronym (pronounced “ask-ee”) for AmericanStandard Code for Information Interchange.ASI Abbreviation for American Standards Institute.A-scope A radar system that displays an A-SCAN.Askarel A synthetic, nonflammable liquid dielectric.aspect ratio The width-to-height ratio of a videoimage, generally three units high by four unitswide.asperities On the surface of an electrode, tinypoints at which the electric field is intensified andfrom which discharge is highly probable.ASR 1. Abbreviation of AIRBORNE (or AIRPORT)surveillance radar. 2. Abbreviation of AUTO-MATIC SEND/ RECEIVE.ASRA Acronym for automatic stereophonic recordingamplifier.assemble 1. To gather subprograms into a completedigital computer program. 2. To translate a