SPACE and ELECTRONIC WARFARE LEXICON SEW Lexicon GHI

SPACE and ELECTRONIC WARFARE LEXICON  SEW Lexicon GHI


G
GALLIUM ARSENIDE (GaAs) - A compound used in integrated circuits (ICs). [10:12] NOTE: GaAs provides a speed of electron mobility about five times that of silicon, and lower power dissipation at the same speed than silicon of the same feature size. Potential GaAs advantages include increased radiation hardness and operation at higher temperatures than can be achieved with silicon. Additionally, the band structure of GaAs allows light-emitting devices to be made, not previously possible with silicon (Recently, etched silicon has also been made to emit light by applying a voltage or a "pumping" light).
GARDIAN - An acronym for General ARea Defense Integrated ANti-missile.  GARDIAN is a LASER system that utilized a high energy CHEMICAL LASER to protect military assets against low flying tactical threats such as cruise missiles and UNMANNED AERIAL VEHICLEs (UAVs).   GARDIAN generates a laser beam which is focused on a moving target creating immense heat at a single spot, effectively burning a hole in the target.  The laser can engage within a few seconds and locks on until the target is destroyed.  [10:2557]  See also DIRECTED ENERGY WEAPON (DEW).
GARNISHING - In surveillance, natural or artificial material applied to an object to achieve or assist CAMOUFLAGE. []
GARRET SCANNER - An electronic device used to scan rooms for concealed weapons.  It includes a "reduced sensitivity" mode for scanning near floors containing reinforcement bars (rebars).  []
GAS LASER - A LASER in which a gas is used as a light-emitting source.  The electrons in the gas molecules are excited by x-rays plus electrical discharges (calledelectrical/gas lasers), or by chemical reactions (called CHEMICAL LASERs).  The choice of gas determines the color of the output light.  [10:2559]  See also CRYSTAL LASER, DIODE LASER, DYE LASER.
GATE - (1) An interval of time during which some portion of a circuit or display is allowed to be operative. (2) The circuit which provides gating. [3]
GATE DECEPTION - A SELF SCREENING ECM technique that returns a large jamming or on-frequency noise signal back to a victim automatic tracking radar. The jamming signal is much stronger than, and thus masks in the (velocity, range, or angle) gate, the true signal returned by the radar cross section of the jamming platform. The jamming signal is then gradually increased or decreased relative to the true return signal, causing the radar's gate to move away from the true signal. After a specified time or signal-magnitude, the jamming signal is turned off, causing the radar to lose its track and go into a search mode to reacquire the target. This process then repeats itself. [8]
GATEWAY - A device that forwards information from one network to another.  [10:2619]  Also called a ROUTER or switch.
GATING - (1) The process of selecting those portions of a signal that exist during one or more selected time intervals. (2) (Radar) The application of enabling or inhibiting pulses during part of a cycle of equipment operation. [3]
GATOR MINE - A component of the Navy's CBU-78/N and the Air Force's  CBU-89/B air-launched cluster bombs.  Each Navy bomb contains 15 antipersonnel and 45 antitank Gator mines; each Air Force bomb contains 22 antipersonnel and 72 anti-tank Gator mines.  Gator mines can also be deployed from vehicles and helicopters using the VOLCANO multiple delivery mine system. [10:2735]
GENERIC WEAPON - A weapon that is useful against any target. []
GENETIC ALGORITHM (GA) - A computer algorithm based on the mechanisms of biological natural selection, using populations of objects which can reproduce based on the biological concepts of survival of the fittest and mutation. [10:51]
GENETIC ANTENNA - An antenna designed through use of GENETIC ALGORITHMs to best meet the antenna specifications.  It is particularly useful in situations where existing designs are not adequate.  [10:2602]  See also FRACTAL ANTENNA.
GENETIC DATA MINING - The automatic extraction of prediction and classification rules from databases using advanced GENETIC ALGORITHMS.  [10:2767]
GENOMICS - (1) The study of genes and their function.  []  (2) A new technology combining biotechnology, genetic engineering, and microelectronics.  []
GEOPOSITIONING - The placement, by radio control, of a satellite from one GEOSYNCHRONOUS position to another.  []
GEOSTATIONARY SATELLITE - A satellite that has a circular orbit, lies in the plane of the earth's equator, and moves about the earth's polar axis in the same direction and with the same period as the earth's rotation.  Thus, the satellite remains above a fixed point on the earth's equator.   [10:14]  See also GEOSYNCHRONOUS SATELLITE.
GEOSYNCHRONOUS SATELLITE - A satellite that orbits the earth such that it remains stationary with respect to a given point on the earth because its orbit has the same period of revolution as the earth.  That is to say that a radial line originating at the center of the earth and passing through the point of interest on the surface of the earth will also pass through the satellite. [10:2620*]  See also GEOSTATIONARY SATELLITE, MOLNIYA ORBIT.
GIANT MAGNETORESISTANCE (GMR) - An application of MAGNETOELECTRONICS.   In a GMR material, consisting of a stack of alternating layers of magnetic and nonmagnetic atoms, a small magnetic field can produce a large change in electrical resistance, thus allowing great increases in hard drive densities.  [10:2782]
GLARE LASER - A NONLETHAL WEAPON intended to cause temporary loss of sight to the targeted individual (TI).  [10:2730]
GLINT -- The inherent random component of error in measurement of position or Doppler frequency of a complex target due to interference of the reflections from different elements of the target.  [3]
GLINT ENHANCE JAMMING -- A jamming technique which features a jamming signal transmitted alternately from different antennas, switching from one antenna to the other either sequentially or randomly.  []
GLOBAL AREA STRIKE SYSTEM (GLASS) - A system incorporating a HIGH-ENERGY LASER (HEL) system, a KINETIC ENERGY WEAPON (KEW) system, and a transatmospheric vehicle (TAV).  The HEL system consists of ground-based lasers and space-based mirrors which direct energy to the intended target.  The KEW system consists of terminally-guided projectiles, and the TAV is a flexible platform capable of  supporting maintenance and replenishment of the space assets, and can be used for rapid deployment of special operations forces (SOF).   [USAF 2025 Study]
GLOBAL INFORMATION MANAGEMENT SYSTEM (GIMS) - A network of intelligent information gathering, processing, analysis, and advisory nodes.  GIMS collects, stores, analyzes, fuses, and   manages information from ground, air, and space sensors and all-source intelligence.  Sensors used include acoustic, optical, radio frequency (RF), olfactory, etc.  It employs neural processing to provide information tailored to the user's personal requirements.  [USAF 2025 Study]
GLOBAL NAVIGATION SATELLITE SYSTEM (GLONASS) - A Russian small lightweight jammer designed to jam the Global Positioning System (GPS) []
GLOBAL POSITIONING SYSTEM (GPS) - A constellation of 21 operating satellites and three in-orbit spares (1995).  Each satellite continuously emits a pair of signals by which the system's precision and accuracy are achieved.  GPS receivers employed by various users can provide positioning accuracy to within centimeters.  [10:2573] NOTE: The determining of position of a GPS receiver requires the simultaneous measurement of the distances to four orbiting satellites.  The measurement of raw range from a single satellite places the receiver on the surface of a sphere centered on the satellite with a radius equal to the measured range.  A simultaneous measurement of the range to a second satellite creates a second sphere that intersects the first and creates a sector upon which the receiver may be found.  A third measurement produces the intersection of three spheres with only two points common to all three.  One of these points will be in space, the other at the receiver's terrestrial position.  In theory, these three measurements should be sufficient to produce an unambiguous positional fix.  In practice, however, the inaccuracy of the user's inexpensive clock must be accommodated by a range measurement to a fourth satellite.  At this point there are four unknowns -- the user's longitude, latitude and altitude measured from the center of the earth, as well as the bias required to bring the user's clock error into synchronicity with system time and four independent range equations.  Solving the system of equations yields user position data to an accuracy of at least 15 meters and time to within 100 NANOSECONDs.  [10:2599]  There are at least two levels of precision associated with GPS --  Coarse/Acquisition (C/A) code, which involves ionospheric and geoid correction algorithms, and encrypted Precision (P) code, presumably for ballistic missile and other military usage.
GLOBAL SURVEILLANCE, RECONNAISSANCE, AND TARGETING SYSTEM (GSRT) - A space-based all-sensor collection, processing, and dissemination system which provides a real-time information database.  This database is used to create a VIRTUAL REALITY (VR) image of the area of interest, thus providing all levels of command SITUATIONAL AWARENESS (SA), technical and intelligence information, and command & control (C2).  [USAF 2025 Study]
GOVERNMENT OSI PROFILE (GOSIP) - A subset of OPEN SYSTEM INTERCONNECTION (OSI) standards specific to U.S. Government procurements, designed to maximize interoperability in areas where plain OSI standards are ambiguous or allow too many options.  [10:2736]
GRACEFUL DEGRADATION - A system design feature to prevent catastrophic failure by allowing the system to operate at a predictably decreasing capability in the presence of increasing subsystem failure. []
GRASER - Gamma X-ray laser. [] NOTE: Grasers are small-size devices having potential for use as directed energy weapons.
GRAY - A term used to indicate countries other than the U.S. or the Soviet Union; e.g., gray forces, gray equipment. [] Contrast with BLUE, RED FORCES.
GRAYBODY - A temperature radiator whose spectral emissivity is less than unity and the same at all wavelengths. [3] NOTE: Graybody radiation can emanate from an infrared-generating missile in flight: from the leading edges, exhaust smoke, and the engine enclosure.
GRAYBODY RADIATOR - A flare designed to emit over a wide spectrum. [10:65]
GRAY-HAT HACKER - A HACKER whose aim is to publicly expose security flaws in software, and who generally posts the results on the Internet.   []  Contrast withCRACKER.   See also BLACK-HAT HACKER.
GRID - A VACUUM TUBE element used to control the electrical current flowing through the tube by varying its voltage with respect to that of the CATHODE. []
GRIDLOCK - (1) The process of removing navigational and radar biases by calibrating to a common force reference point. This is accomplished by all units of the force simultaneously recording the position of a commonly-held target that has a specified relative position from the force center (or other reference point) at the same instant. [] (2) The computer process used to compare an individual ship's track data with remotely originated track data, and to determine the correction necessary to bring the tracks into alignment. [10:84]
GROUND-BASED ELECTRO-OPTICAL DEEP SPACE SURVEILLANCE SYSTEM (GEODSS) - A system of three telescope sensors linked to video cameras, which feed their space pictures into a nearby computer for display on a monitor and recording on magnetic tape.  []
GROUND CLUTTER - CLUTTER resulting from the ground or objects on the ground. [3] See also RADAR CLUTTER, WAVE CLUTTER.
GROUND EFFECT - A condition which occurs when a helicopter hovers near (within 1/2 rotor diameter) of the ground, and is due to the interference of the surface with the airflow pattern of the rotor system.  When a helicopter is hovering In Ground Effect (IGE), blade efficiency increases, and less power is required than a hover Out of Ground Effect (OGE).  [10:2776] NOTE:  Maximum ground effect is achieved when hovering over smooth paved surfaces.
GROUND-EMPLACED MINE SCATTERING SYSTEM (GEMSS) - A mine dispenser designed to be towed by a vehicle.   It flips one mine out of a tube every two seconds, and is capable of  thus scattering up to eight hundred antipersonnel mines and/or antitank mines per load.   The mines are similar to those used by the ADAMsystem.  [10:2735]
GROUND HOMING ON PSEUDO-TARGET - An ECM technique consisting of pointing the ECM antenna in a direction other from that of the victim radar in order to create off-angle noise strobing or false targets. [8*]
GROUNDING - The BONDING of an equipment case, frame or chassis, to an object or vehicle structure to ensure a common [electrical] potential. [1] See alsoEARTHING.
GROUND PENETRATING RADAR (GPR) - A radar which produces ultrawide-band impulses that penetrate ground substrata and produce signal reflections from more dense deposits contained therein.  [10:2681]  Also called GPEN RADAR.  NOTE: GPRs have been used to detect deposits of gold ore lying two-to-three feet deep within the tunnel wall of a working gold mine.  This technology has also been used for detection of subterranean tunnels and fortifications as well as buried antipersonnel and antivehicle mines.  In this latter role, however, GPR does not perform well in dry soil and produces false positives from rocks and tree roots.  [10:2674]   A hand-held GPR system that integrates the ground penetrating radar with a pulsed induction metal detector to produce a unit that can be used by a combat engineer or infantryman to reliably detect buried mines, including heavy anti-tank mines and small plastic anti-personnel mines. [10:2702]
GROUND WAVE - A radio wave that is propagated over the earth and is ordinarily affected by presence of the ground and troposphere. [3] Contrast with SKY WAVE.
GUARD BAND - A frequency band between two channels which gives a margin of safety against mutual interference. [3]
GUARD GATING - An ECCM technique wherein the velocity- and/or range-gate of a tracking radar is protected from GATE DECEPTION, CHAFF, and other forms ofECM by the use of additional gates. [8]
GUARDRAIL/COMMON SENSOR (GR/CS) - An airborne SIGINT collection/location system that integrates the Improved GuardRail V (IGR V), the Communication High Accuracy Airborne Location System (CHAALS) and the Advanced QUICKLOOK (AQL) into the same platform aircraft.  The system consists nominally of twelve aircraft which                                                 perform operational missions in flights of three.  [10:2811]  NOTE:  The GR/CS can employ five operation modes, selectable by the mission commander:  Direct Tether - each aircraft talks to its own tracking operator via a datalink;  Extended Tether - The aircraft talks to both the ground station and to the other two aircraft in the flight of three;  Untethered - The aircraft records data while aloft for later downloading;  Repeater Operations - Extended data-collection capability with downlink to a ground vehicle, which in turn retransmits the data to a satellite for global redirection when a downlink is available; and  Direct Air-to-Satellite Relay -- All three aircraft transmit directly to a satellite, which in turn relays to an Integrated Processing Facility (IPF) ground station that does not have to be in the operational area.
GUIDED MUNITION - A "one-on-one" munition:  A specific munition engages a specific taget, which is advantageous during close combat situations.  An operator is required in the loop to select the target and often assist in the guidance.  The munition may be either COMMAND-TO-LINE-OF-SIGHT (CLOS), or possess HOMING GUIDANCE.  [12]   Contrast with BRILLIANT MUNITION.  See also SMART MUNITION.
GULL - In electronic warfare, a floating radar reflector used to simulate a surface target at sea for deceptive purposes. []
GYROCHIP - An angular rate sensor designed to be a reliable replacement for iron gyros.  It is a single piece of piezoelectric quartz shaped like a double-ended tuning fork.  It uses the Coriolis effect in determining angular rate.  The unit operates on 600 milliwatts if DC power and has no motors or bearings and is essentially solid-state. The gyrochip is used in applications that include helicopter yaw control, infrared line of sight stabilization, missile flight control and guidance, parachute instrumentation and periscope stabilization.  [10:2524]
GYROTRON - A high power microwave generating device suitable for use as a DIRECTED ENERGY WEAPON in the MILLIMETER WAVE band. [10:16] See alsoBEAM-PLASMA DEVICE, FREE- ELECTRON LASER; VIRTUAL-CATHODE OSCILLATOR.
________________________________________
October 06, 2001 07:49 AM -0400
H
HACKER - A person who delights in having an intimate understanding of the internal workings of a system - computers and computer networks in particular.  The term is almost universally misused in a pejorative context, where CRACKER would be the correct term.  [10:2736]   Also called WHITE HAT HACKER.  See also GRAY-HAT HACKER.
HAND-EMPLACED JAMMER - A lightweight, man-portable, expendable solid-state jammer with self-disabling features, designed to be hand-emplaced to operate against threat signals. [4:26] See also LEAVE-IT-BEHIND JAMMER.
HANDOFF - The passing of tracking responsibility from one system to another, such as from a search radar to a fire-control radar. []
HANDSHAKING - Part of a communications PROTOCOL that requires the interchange of predetermined signals between devices prior to making a connection. [10:45]
HARD KILL - The physical destruction of a weapon or a platform through employment of electronic counter- measures techniques, bombs, or missiles. [] Contrast withSOFT KILL, FIRM KILL.
HARD-KILL ECM - HARD KILL weapons which employ electronic warfare concepts to achieve target destruction. [] See also DIRECTED ENERGY WEAPON,FRONT-DOOR SYSTEM PENETRATION, BACK-DOOR SYSTEM PENETRATION; LETHAL ELECTRONICS COUNTERMEASURES.
HAVE STARE (HS) - An X-band (8-12 GHz) 200 kw tracking RADAR that can detect small space debris in the 1 to 10 cm range, depending on altitude. []
HAYSTACK LONG RANGE IMAGING RADAR (LRIR) - Part of the Millstone Haystack complex consisting of two radars that share hardware and power which precludes simultaneous operations. The two radars are the Haystack Long Range Imaging Radar (LRIR) and the Haystack Auxiliary Radar (HAX). These radars support missions for the U.S. Space Command, the National Science Foundation, and NASA. Their primary function is for deep space imaging of foreign and domestic satellites and orbital debris. The radars image every new foreign space launch in Near Earth (NE), and image domestic satellites in trouble.  The LRIR takes two-dimensional images of earth satellites by processing highly stable, coherent signals to extract target return range and doppler information. The radar is capable of tracking and imaging near-earth (NE) satellites, 200-4,000 km altitude, as well as deep space objects out to 40,000 km range and beyond. The maximum tracking rate of the Haystack antenna is 2 degrees/second, and this sets the limits on observation of near-earth satellites, especially those passing nearly overhead. The limitation on deep space objects is their size: a one square meter radar cross section at 40,000 km is roughly the detection threshold of the radar. The radar operates at 10-GHz center frequency and transmits over a broad range of pulse widths and pulse repetition frequencies, including a 1-GHz linear FM pulse which, when compressed, is used for radar imaging. The radars also provide detection of objects in space and gather information about their estimated size, velocity, altitude, and direction of travel.  [10:2804]
HAZARDS OF ELECTROMAGNETIC RADIATION TO PERSONNEL, ORDNANCE, AND VOLATILE MATERIALS (HERO) - See ELECTROMAGNETIC RADIATION HAZARDS.
HEAD-UP DISPLAY (HUD) - A display of flight, navigation, attack, or other information superimposed upon the pilot's forward field of view. [1] See also HORIZONTAL SITUATION DISPLAY, VERTICAL SITUATION DISPLAY.
HEALING AGENT - See AUTONOMIC HEALING
HEDGEHOG (HH) - An anti-submarine mortar-like projectile used by destroyers and anti-submarine ships circa 1942 - 1960.   They were favored over depth charges because they could be fired in patterns 100-150 yards ahead of the ship while it still maintained sonar contact with the target submarine.  Each hedgehog was approximately 7 inches in diameter at the warhead end and carried 30 lbs of TNT (or 34 lbs of Torpex).  Twenty-four hedgehogs were mounted in open view in a cradle-like base on the bow of the ship.  The cradle was mounted on a power drive which allowed a training arc of 20 degrees on either bow (later versions allowed a full gun train).  The ring-finned tail of each hedgehog was sleeved to a rod mount called a spigot which held the firing pin.  The spigots also had a tilt capability to compensate for the roll-and-pitch motion of the deck .  Hedgehogs were fired in pairs at intervals which deployed the 24 weapons in a 1 - 1.5 second interval, forming a circular pattern at water entry.  [ALL HANDS magazine, April 1958, p45]  See also MOUSETRAP. NOTE:  Hedgehogs had the additional advantage over depth charges (which detonated at preset depths) in that they did not detonate except on contact.  This if the submarine was not hit, sonar conditions were not deteriorated by bubbles and water disturbance generated by a detonation, as with depth charges.   Click to viewphotos and additional information about hedgehog installations.
HELICOPTER MINE - A device which will autonomously search, detect, track, identify, engage and destroy enemy helicopters flying at speeds up to 350 kilometers per hour and at altitudes up to 250 meters.  It possesses a positive hostile target signature identification processor that sorts and identifies helicopter acoustic signatures.  The mines can be equipped with countermobility remote control system transceivers, enabling them to be de-activated for friendly force passage and mine recovery.  [10:2546]
HERTZ - The unit of FREQUENCY, one cycle per second. [3]
HETERODYNE LADAR - See HOMODYNE LADAR.
HIDDEN SCAN - An ECCM technique for use by semi-active missile guidance receivers. [8] See also INVERSE GAIN ECCM.
HIGH ENERGY DENSITY MATERIAL (HEDM) - Material composed of high- energy ingredients, such as explosives, propellants, and pyrotechnics. [10:89]
HIGH ENERGY LASER (HEL) - A HARD-KILL ECM device which employs lasers used as directed energy weapons. They work by accelerating electrons to very high velocities, then causing them to radiate some of their kinetic energy at the proper wavelength and in the proper direction in resonance with light waves in the electron beam. [5:1] EXAMPLES: X-RAY, CHEMICAL, FREE-ELECTRON, and EXCIMER LASERs.
HIGH ENERGY MILLIMETER WAVE (MMW) - Directed energy in the MILLIMETER WAVE region of the ELECTROMAGNETIC SPECTRUM. []
HIGH-ENERGY LASER WEAPON SYSTEM (HELWEPS) - A defensive system incorporating a HIGH ENERGY LASER (HEL) designed to protect Aegis-class cruiser and destroyers against high-speed, sea-skimming cruise missiles.  The self-contained, modular (fire-control, ammunition, and pump) weapon configuration is intended to replace a ship's forward 5-inch/54 gun mount.   The device is a deuterium-fluoride (DF) LASER which produces a coherent beam that can (with only about 1-second engagement duration) destroy missile targets radomes at 4 kilometers, and optical systems at up to 10 kilometers.   [10:2560]  See also MIRACL.
HIGH ENERGY RADIO FREQUENCY (HERF) - A weapon that can direct high levels of RF radiation at digital devices such as computers and navigation equipment, thereby disrupting their operation. []  Also called EMP/T BOMB.
HIGH-FREQUENCY SURFACE WAVE ARRAY RADAR (HIFAR) - A BISTATIC RADAR   operating in the HF (3 - 30 MHz) range, used for ocean surveillance.  At these frequencies, the radar waves propagate over the ocean surface for long distances, well beyond the normal radar horizon.  []
HIGH OFF-BORESIGHT SYSTEM (HOBS) - A helmet-mounted sight and short-range missile system to combat Mig-29s.  []
HIGH POWER COMBINER - A radio frequency (RF) device which combines the outputs of multiple solid state amplifiers over a given frequency range.  []
HIGH-POWERED MICROWAVES - See HIGH-POWERED RF.
HIGH-POWERED RF - A term replacing HIGH-POWERED MICROWAVES, high-power energy roughly above 1,000 MHz. []
HIGH-POWER SOURCE NOISE JAMMING - A type of BARRAGE JAMMING in which noise is added to the high-power signal of the jammer. [10:36] Contrast withLOW-POWER SOURCE NOISE JAMMING.
HIGH POWERED ACOUSTIC WEAPON - A NONLETHAL WEAPON versatile high power acoustics system with a tunable, less-than-lethal incapacitating capability.  [10:2745]   See also ACOUSTIC WEAPON.
HIGH SPEED ANTI-RADIATION MISSILE (HARM) - High-speed anti-radiation missiles designed for use against early-warning radars and air defense systems. [] See also ANTI-RADIATION MISSILE.
HIGH-SPEED CHOP - A technique to achieve compatibility between RADAR WARNING RECEIVERs (RWRs) and ECM systems. The receiver and transmitter operate effectively simultaneously by implementing a high-speed time sharing scheme. [10:2400] See also LOOK AROUND, LOOK OVER, and LOOKTHROUGH.
HIGH TEMPERATURE SUPERCONDUCTIVITY (HTSC) - Superconductivity at temperatures above 125 degrees Kelvin (-234 degrees Fahrenheit). [10:116]
HOG NOSE - See RIVET JOINT
HOG CHEEKS - See RIVET JOINT
HOLE-FINDING - An ECCM technique used against a noise jammer which partially covers a radar frequency band. It consists of scanning the receiver bandwidth at the end of a pulse repetition period to determine the frequency having the lowest jamming level at which the radar will operate during the next pulse repetition period. [8] Synonymous with HOLE-HUNTING and HOLE-SEEKING.
HOLE-HUNTING - See HOLE- FINDING.
HOLE-SEEKING - See HOLE- FINDING.
HOLOGRAM - An in-depth apparent three-dimensional image with great realism produced by illuminating an object field with two interrelated coherent light beams, one directly from a light source and the other slightly delayed, thus giving the three-dimensional appearance. [10:14]
HOLOGRAPHIC DATA STORAGE SYSTEM (HDSS) - Optical interference images recorded in a light-sensitive, usually erasable, medium.  To achieve high storage density, the images are multiplexed -- that is, more than one image occupies the same volume within the crystal.  To differentiate among images, subtle recording differences, such as changing the reference angle, changing the wavelength of the laser light, or other optical stratagems, are used.   Later, the inverse optical conditions are used to reconstruct the hologram so that data can be optically or photographically read out.  [10:2594]
HOLOGRAPHIC MEMORY - A four- dimensional (the fourth dimension is wavelength) storage medium based on a method called "spectral hole burning" to retain holographic images (HOLOGRAMs), which can later be retrieved using low level laser rays. [10:2410]
HOME-ON-JAM (HOJ) - A means whereby a missile guidance receiver utilizes the self-screening target jamming signal to develop angular steering information so that the missile can home on that target. [8]
HOMING GUIDANCE - A system by which a missile steers itself towards a target by means of a self-contained mechanism which is activated by some distinguishing characteristics of the target. [1] See also ACTIVE HOMING GUIDANCE, PASSIVE HOMING GUIDANCE, SEMI-ACTIVE HOMING GUIDANCE.
HOMODYNE LADAR - A laser radar which includes an optical detector constantly receiving a local oscillator (LO) signal in the form of a low-power laser beam. When a reflected return from a target is received, the returned beam is combined with the LO beam on the optical detector which picks up the difference frequency between the two beams. The frequency of the beat signal indicates target relative speed and direction. [] Synonymous with HETERODYNE LADAR.
HOP - (1) In FREQUENCY HOPPING (HF), the shifting of a transmitter from one frequency to another.  []  (2) For network ROUTING, a segment of a path to a destination on a network (a path from the origin to a destination on a network is a series of hops through ROUTERS).  [10:2736]  See also ROUTE.
HORIZONTAL SITUATION DISPLAY - An electronically generated display on which navigation information and stored mission and procedural data can be presented. Radar information and television picture can also be displayed either as a map overlay or as a separate image. [1] See also HEAD-UP DISPLAY, HORIZONTAL SITUATION INDICATOR, VERTICAL SITUATION DISPLAY.
HORIZONTAL SITUATION INDICATOR (HSI) - An electronically generated display that provides a basic horizontal view of the aircraft's navigation picture.  []  NOTE:  In the F-15E, for example, HSI can provide navigation data to selected ground navigation facilities such as TACAN or Instrument Landing System (ILS), or to onboard navigation systems such as the Inertial Navigation System (INS).
HORN - An antenna consisting of a waveguide section in which the cross- sectional area increases toward an open end which is the aperture. [3]
HORN ANTENNA - A radiating element having the shape of a horn. [3]
HOST-BASED INTRUSION DETECTION - A type of INTRUSION DETECTION that examines computer operations data to detect HACKERS.  [10:2853]  Also called COMPUTER-BASED INTRUSION DETECTION.  See also ANOMALY DETECTION, NETWORK-BASED INTRUSION DETECTION, PORT SCAN,SIGNATURE DETECTION.
HOSTILE ARTILLERY LOCATOR (HALO) - A system which will detect and locate all sources of high energy sound and provide rapid analysis and identification of artillery, guns, mortars and machine guns.   It is accurate to 20 meters at range of 15 km; and can work at ranges of 30-40 km.   [10:2732]  NOTE:  HALO processes signals from pre-positioned microphones to identify specific types of ordnance by the acoustic waves they make in flight.  HALO can also identify and track engine sounds and even human footfalls. [10:2889]
HOT CHAFF - An infrared counter- measure employing small chaff elements which generate infrared radiation when exposed to air. When deployed, hot chaff generates a broad signature source which counters an infrared detector's decoy discrimination features. [] See also INFRARED COUNTERMEASURES.
HOVERING DECOY - See NULKA.
HUMAN FACTORS ECCM - A generic ECCM technique that covers the ability of an electronic warfare officer (EWO), a radar operator, a military vehicle operator, a commanding officer, and/or any other EW-associated personnel to recognize the various kinds of ECM, to decide what the appropriate ECCM should be, and/ or to take the necessary ECCM action within the framework of this command structure. [8]
HUMAN FACTORS ECM - A generic ECM technique that covers the ability of an EW-related individual or supervisor to recognize the need for ECM, to decide what the appropriate ECM should be, and to take the necessary ECM action within the framework of the individual's command structure. [Patterned after the definition of HUMAN FACTORS ECCM from reference 8]
HUMAN INTELLIGENCE (HUMINT) - A category of intelligence derived from information collected and provided by human sources. [1] See also HUMAN RESOURCES INTELLIGENCE.
HUMAN RESOURCES INTELLIGENCE - The intelligence information derived from the intelligence collection discipline that uses human beings as both sources and collectors, and where the human being is the primary collection instrument. Sometimes called HUMINT. [1] See also HUMAN INTELLIGENCE.
HUMANE WEAPON - See NONLETHAL WEAPON (NLW)
HUNTER SENSOR SUITE (HSS) - A vehicular integrated, long-range target acquisition suite mounted on an extendible mast assembly platform, remotely controlled from an operator's station located inside the vehicle, e.g., HMMWV.  HSS operates both on the move and stationary.  The integrated sensor suite includes 2nd-generationTHERMAL IMAGING, ACOUSTIC DETECTORS, day TV, Eyesafe laser Rangefinding, Aided Target Recognition (ATR), high density integrated processing. color digital maps, image compression/transmission, GLOBAL POSITIONING SYSTEM (GPS), North-Seeking Module (NSM) and secure communications.  [10:2801]
HYBRID CHANNELIZED/SUPERHETERODYNE RECEIVER ARCHITECTURE - A receiver system that uses multiple-channel channelizers to provide frequency video and to act as a pulse-by-pulse tuner for the associated narrowband superheterodyne receiver. A portion of each received signal is fed into the channelizer, with the remaining signal going straight into the superheterodyne after a delay of several hundred nanoseconds. Both receivers generate amplitude video, offering a higher probability of intercept with high levels of sensitivity and measurement accuracy. []
HYBRID SPACE MINE - A variation of the SPACE MINE.  The hybrid space mine is maintained in a "storage orbit" and is maneuvered to its target by command signals.  A hybrid space mine's storage orbit may be such that it is covertly placed among drifting space debris until the time it is maneuvered to its target.  [5.8]
HYBRID THREAT - A threat resulting from a mix of systems having differing national origins, such as a Soviet aircraft using a French IFF system. []
HYDROGEN FLUORIDE (HF) LASER - A CHEMICAL LASER which combines heated hydrogen (produced in a combustion chamber similar to the one in a rocket engine) with fluoride gas to produce excited hydrogen fluoride molecules.  The light beam that results radiates on multiple lines between 2.7 µm and 2.9 µm.  These wavelengths transmit poorly through the atmosphere.  Even so, the BALLISTIC MISSILE DEFENSE (BMD) organization is considering (1997) HF lasers for space-based defenses needing to propagate through only he upper atmosphere.  [10:2607]  See also DEUTERIUM FLUORIDE (DF) LASER.
HYDROMAGNETICS - The science that deals with an electrically conducting fluid, as a liquid metal or an ionized gas. [] Also called MAGNETOHYDRODYNAMICS. See also MEASUREMENT AND SIGNATURE INTELLIGENCE.
HYPERENCRYPTION - The hiding of a message within a very large stream of data.  [10:2906]  NOTE:  In the face of hyperencryption, a code-breaker would be unable to store the message-within-data for eventual decoding because the total amount would simply be overwhelming.
HYPERLINK -- (1)  A pointer from a segment of text or from an image to a BOOKMARK or UNIVERSAL RESOURCE LOCATOR (URL), which may be located on the same page, another page or computer file in the web site in which the hyperlink exists, or to a file or bookmark in another web site on the World Wide Web.  Hyperlinks allow the user to navigate between bookmarks on the same page (example: click here to move to the bookmark "HYDRODYNAMICS" above), to other files on the same site (as most of the hyperlinks in this lexicon) or to bookmarks or files on other web sites (as in the hyperlinks to sound files under ELECTROMAGNETIC JAMMING).  (2) A pointer within a HYPERTEXT document which points (links) to another document, which may or may not also be a hypertext document. See also HYPERTEXT MARKUP LANGUAGE (HTML).  []
HYPERSPECTRAL IMAGERY -- A process in which visual light is significantly enhanced by a computer processor, enabling the smallest changes in color variance of the water to be detected, thus improving the ability to detect submarines.  [10:2656]   The HYPERSPECTRAL (IMAGING) SENSOR is designed to provide a detailed analysis of the entire light spectrum from visible light up to FAR INFRARED.  Current (1999) multispectral imaging sensors can break this range into a dozen or more sections for individual analysis.  The hyperspectral imaging sensor can examine extremely narrow bands of this range, allowing the sensor to look for specific chemical compositions that reflect light only in those very narrow bands.  This provides a capability to "look" through dense foliage and detect, for example, camouflage paint.   The image presented to the sensor's user would give a visual representation of that "hidden" source in the same manner as infrared or other displays.  [10:2692]  See also AIRBORNE TARGETING AND CROSS-CUEING SYSTEM (ATACCS), LITTORAL AIRBORNE SENSOR-HYPERSPECTRAL (LASH), HYPERSPECTRAL SENSOR.
HYPERSPECTRAL SENSOR - A reconnaissance sensor system used to quickly pinpoint objects that are undetectable to traditional ELECTRO-OPTIC (EO) equipment.   The system divides the incoming optical radiation into hundreds of spectral bands and analyzes that information for specific signatures unique to a scene.  The signatures are processed in a way that allows accurate detection of objects that are different from their backgrounds.  [10:2590]   Synonymous with HYPERSPECTRAL IMAGING SENSOR.  See also PORTABLE HYPERSPECTRAL IMAGER FOR LOW LIGHT SPECTROSCOPY (PHILLS).  NOTE:   A HYPERSPECTRAL IMAGING SENSOR is aMULTISPECTRAL IMAGING SENSOR having more than 20 discrete spectral bands.  [12]
HYPERTEXT - A document, written in HYPERTEXT MARKUP LANGUAGE (HTML), which contains HYPERLINKS to other documents, which may or may not also be hypertext documents. Hypertext documents are usually retrieved from the INTERNET, using the WORLD WIDE WEB (WWW).   [10:2736]
HYPERTEXT MARKUP LANGUAGE (HTML) -- A programming language used to build Web sites.  It contains standard codes, or tags, that determine how a Web page looks when a browser displays it. ( For a listing of current HTML tags, click  ).  HTML tags may be used to create headings, paragraphs, and lists.  HTML tags also make possible the HYPERLINKs that connect information on the World Wide Web.  []   See also DYNAMIC HYPERTEXT MARKUP LANGUAGE,GENERALIZED MARKUP LANGUAGE, JAVA   NOTE:  In most browsers, you can see the underlying HTML code for the displayed page by selecting the Menu item "View", and then "Source".
HYPERVELOCITY INTERCEPTOR - A KINETIC KILL VEHICLE that can reach speeds of more than 8,000 feet per second within fractions of a second after launch. [10:74]
________________________________________
September 28, 2001 06:43 AM -0700
I
IDENTIFICATION - The process of determining the friendly or hostile character of an unknown detected contact. [1] See also TARGET IDENTIFICATION.
IDENTIFICATION, FRIEND OR FOE (IFF) - A system using electromagnetic transmissions to which equipment carried by friendly forces automatically responds, for example, by emitting pulses, thereby distinguishing themselves from enemy forces. [1] See also COOPERATIVE TARGET IDENTIFICATION.
IGNITION SPIKE - The initial, intense, short-duration radiative emission occurring when a FLARE begins burning. [10:27] NOTE: An ignition spike is the emission caused by the energy given off by the igniter material (e.g. a squib) rather than the energy given off by the flare which it ignites. This emission may be more intense, hence distinguishable from that of the flare, making it detectable by an ECCM system.
ILLUMINATED CHAFF (ILLCH) - A JAFF technique in which jamming energy is directed at deployed chaff so that the energy will be reflected to the victim sensor. []
ILLUMINATOR - A system designed to impose electromagnetic radiation on a designated object so that the reflections can be used by another sensor, typically for purposes of homing. [3] See also SEMI-ACTIVE HOMING GUIDANCE.
ILLUMINATOR GRENADE - A NONLETHAL WEAPON consisting of a grenade which provides illumination for dark rooms.  [10:2745]
IMAGE DISPLAY - That aspect of IMAGERY EXPLOITATION involving pseudo-color, brightness, density slicing, registration with a reference image, addition/subtraction of two images, flicker between two registered images, stereo, overlay of graphic cues (SIGINT error ellipses, target symbols), image windows, split screen, and quad screen. [10:2443]
IMAGE-ENHANCED MIXING - An ECCM technique for use in monopulse tracking radars that depend on phase sensing for angle tracking. The objective is to use the repeated signal from an IMAGE JAMMER as a beacon for tracking the target. [8]
IMAGE ENHANCEMENT - That aspect of IMAGERY EXPLOITATION involving dynamic range adjustment, edge enhancement, smoothing/ noise filtering, and warping. [10:2443]
IMAGE FREQUENCY - An undesired input frequency capable of producing the selected frequency by the same process. [3] NOTE: An image frequency is a frequency which differs from, but has a certain symmetrical relationship to, that which a superheterodyne receiver is tuned. Consequently, the image frequency can be mistakenly accepted and processed as a true frequency by the receiver.
IMAGE INTENSIFICATION - The increasing of the intensity of a radiant image through use of optoelectronic amplification. []
IMAGE JAMMING - (1) A self-screening ECM technique for use against tracking radars that depend on phase sensing for angle tracking. The technique involves radiating a signal on the image frequency of the victim radar. [8] (2) Jamming the image frequency of a monopulse radar causing the antenna to be driven away from the target. Not effective if the radar uses IMAGE REJECTION. [4:1]
IMAGE MANIPULATION - That aspect of IMAGERY EXPLOITATION that involves image roam, zoom, and rotation. [10:2443]
IMAGE REJECTION - An ECCM technique incorporated as a feature in radar receiver design. The design attenuates image-signal frequencies so that IMAGE JAMMINGmethods will have little or no effect on the radar operation. []
IMAGERY - Collectively, the representations of objects reproduced electronically or by optical means on film, electronic display devices, or other media. [1]
IMAGERY EXPLOITATION - The extraction of needed intelligence from imagery data. Imagery exploitation consists of IMAGE MANIPULATION, IMAGE ENHANCEMENT, IMAGE DISPLAY, GEOPOSITIONING, . [10:2443]
IMAGERY INTELLIGENCE (IMINT) - Intelligence information derived from the exploitation of collection by visual photography, infrared sensors, lasers, electro-optics and radar sensors such as synthetic aperture radar wherein images of objects are reproduced optically or electronically on film, electronic display devices or other media. [1]
IMITATIVE COMMUNICATION DECEPTION - That division of DECEPTION involving the introduction of false or misleading but plausible communications into target systems that mimics or imitates the targeted communications. [7:CJCS MOP 6, APPENDIX B]
IMITATIVE ELECTROMAGNETIC DECEPTION - That type of ELECTROMAGNETIC DECEPTION that involves the introduction of electromagnetic energy into enemy systems that imitates enemy emissions. [7:CJCS MOP 6, APPENDIX B]
IMITATIVE ELECTRONIC DECEPTION - The introduction of electromagnetic energy into enemy systems that imitates enemy emissions. [1]
IMPULSE NOISE - NOISE characterized by transient disturbances separated in time by quiescent intervals. [3] Contrast with RANDOM NOISE.
IMPULSE NOISE JAMMING - Noise jamming using a very narrow pulse of high power across a wide BANDWIDTH that covers the bandwidth of the victim radar. [8]
IMPULSE RADAR - (1) A radar characterized by an extremely short pulse (around 1 nanosecond) at an extremely high peak power (in the order of gigawatts). Impulse radars may have resolutions measured in inches. [10:104]  (2) A radar having  a FRACTIONAL BANDWIDTH (FBW) greater than 0.25.  [10:2571]   Also called ULTRA-WIDEBAND RADAR, PICOSECOND PULSE RADAR, NONSINUSOIDAL RADAR, MONOCYCLE RADAR, SHOCK RADAR.  NOTE:  Impulse radars provide improved clutter suppression and range profiling, as well as greater penetration of foliage, earth, and water.
INBOUND RANGE GATE WALK-OFF - A fuze jamming technique used to predetonate a fuze that operates on target range. [4:2]
INCENDIARY GRENADE - A grenade which contains a filler that burns for approximately 40 seconds at a temperature of 4,000 degrees (F).  A portion of the filler turns into molten iron that produces intense heat, igniting or fusing whatever it touches.  It is used to ignite combustible materials, destroy weapons, records, or equipment, or burn holes in metal doors.  [10:2780]  Also called THERMITE GRENADE.  See also WHITE-PHOSPHOROUS GRENADE.
INCIDENT WAVE (Electromagnetic Wave) - A WAVE that impinges on a target. []
INCOHERENT INFRARED SENSOR - An INFRARED sensor which detects incident radiation as the square of the absolute magnitude of the amplitude. Contrast withCOHERENT INFRARED SENSOR. [4:6]
INDICATIONS AND WARNING (I&W) - Those intelligence activities intended to detect and report time-sensitive intelligence information on foreign developments that could involve a threat to the United States or allied military, political, economic interests or to U.S. citizens abroad. It includes forewarning of enemy actions or intentions; the imminence of hostilities; insurgency; nuclear/non-nuclear attack on the United States, its overseas forces, or allied nations; hostile reactions to United States reconnaissance activities; terrorists' attacks; and other similar events. [1]
INDIRECT (FREQUENCY) SYNTHESIS (IS) - FREQUENCY SYNTHESIS where generation of desired frequencies is achieved through interaction of two or more frequency sources. [10:2616]  Contrast with DIRECT SYNTHESIS (DS).
INDIRECT TARGET IDENTIFICATION - Target identification obtained through means other than those associated with the target itself. Examples of such indirect sources are third parties and intelligence. [] See also NON-COOPERATIVE TARGET IDENTIFICATION, TARGET IDENTIFICATION.
INDUCED ELECTROMAGNETIC PULSE (IEMP) - Induced current that is set up within a circuit that is subjected to the radiated field of an ELECTROMAGNETIC PULSE (EMP).  [10:2541]  See also SYSTEM-GENERATED ELECTROMAGNETIC PULSE (SGMP), NEMP COUNTERMEASURES.
INFORMATION BOMB - A controlled flood of information directly inserted into an adversary's computer systems, sensors, or satellites.  [10:2751]
INFORMATION DISCOVERY - See DATA MINING.
INFORMATION FUSION - Fully automated methods of merging data. [] Synonymous with MULTISOURCE CORRELATION or MULTISENSOR INTEGRATION.
INFORMATION HARVESTING - See DATA MINING.
INFORMATION SECURITY (INFOSEC) - A collection of disciplines related to one or more areas of information protection. []   See also ELECTRONIC INFORMATION SECURITY.
INFORMATION SYSTEM PRECEPTS - The seven absolute precepts to follow in building a new fleet information system are listed below.  [10:2775]
INFORMATION SYSTEM PRECEPTS (from IT-21)
If the boss doesn't use it, don't buy it!
Tactical and non-tactical applications must be integrated.
We must stay common with industry.
All applications must be driven to a single PC.
We must use Commercial Off-the-Shelf (COTS) wherever feasible
Sea to shore transitions must be seamless.
No stovepipes!

NOTE:  These are also referred to as "The Seven Habits of a Highly Effective Information System."
INFORMATION WARFARE (IW) - Actions taken to achieve information superiority by affecting adversary information, information-based processes, information systems, and computer-based networks while defending one's own information, information-based processes, information systems and computer-based networks.  [12]   The critical aspects of IW are Information Denial, Information Distortion, and Protection.   See also NETWAR, CYBERWAR.  NOTES: (1) Manipulative, disruptive or destructive actions taken covertly or overtly during peacetime, crisis or war against societal, political, economic, industrial or military electronic information systems.  The purpose is to achieve informational advantage over an adversary and to influence behavior, deter or end conflict or, that failing, to win a war quickly and decisively, with minimal expenditure of capital, resources and personnel and with minimum casualties on either side.  Information Warfare includes actions taken to preserve the integrity of one's own information systems from exploitation, corruption or destruction while at the same time exploiting, corrupting or destroying an adversary's information systems and in the process achieving an information advantage in the application of force.  [10:2570]  (2) Information Warfare entails collecting, processing, and acting upon information faster that the adversary. Information warfare includes False Force Presentation (FFP). []  (3)  The following are forms of information warfare: Command and Control Warfare (formerly C3CM),Intelligence-Based Warfare (IBW),  Electronic Warfare (EW), Psychological Warfare (PSYW), Hacker warfare, Economic Information Warfare (EIW), and Cyberwar.
INFRARED (IR) - The region of the electromagnetic spectrum between the long wavelength extreme of the visible spectrum (about 0.7 micrometers) and the shortest microwaves (about 1 millimeter). [3] See also ELECTRO-OPTIC, NEAR INFRARED, MID INFRARED, FAR INFRARED, EXTREME INFRARED. NOTE: Sometimes referred to as "temperature radiation". Any physical object having a temperature above absolute zero degrees (Rankine or Kelvin) radiates infrared energy. Sources of infrared radiation from an aircraft include reflected sunlight, landing lights, oil heat exchangers, and engine exhaust.
INFRARED COUNTERMEASURES (IRCM) - Those measures employed to counter infrared sensors and weapons. They include INFRARED SIGNATURE reduction (suppression), decoy targets (such as FLARES), and guidance deception (JAMMING). [4:10] See also DIRECTIONAL INFRARED COUNTERMEASURES, HOT CHAFF.
INFRARED IMAGERY - That IMAGERY produced as a result of sensing electromagnetic radiation emitted or reflected from a given target surface in the infrared position of the ELECTROMAGNETIC SPECTRUM (approximately 0.72 to 1,000 microns). [1]
INFRARED IMAGING - The process of sensing the natural thermal radiation emitted by a body because of its temperature. The image is formed from the temperature differences between targets and the background of the scene. [10:88]
INFRARED LINE SCANNER (IRLS) - A one-dimensional INFRARED scanner. The forward motion of the platform provides area scan. See also FORWARD LOOKING INFRARED. [10:24] NOTE: Capable of scanning a swath of from 5 to 10 miles with sufficient resolution to detect and possibly identify potential targets, the infrared line scanner generates data which may be recorded on film or transmitted to the control station via a data link.
INFRARED LINESCAN SYSTEM - A passive airborne infrared recording system which scans across the ground beneath the flight path, adding successive lines to the record as the vehicle advances along the flight path. [1] See also LASER LINESCAN SYSTEM.
INFRARED SIGNATURE - Measurable radiation characteristics of an INFRARED source. []
INFRARED SIGNATURE SOURCES


   IR Sensor	     Graybody radiation from leading edges                                             Graybody from smoke

  Reflected terrain,      Graybody from hot engine      Moderate emission in CO2 and H2O                  sky, sun  radiation                                                               bands from exhaust
INFRARED SIGNATURE CONTROL - The employment of materials, electronics, and platform design features intended to reduce the susceptibility of the platform to detection, tracking, and engagement by an adversary using INFRARED (IR) sensors. This includes the use of IR paints, coatings, films, thermally or electrically activated materials, and techniques for shielding IR sensors from the platform's IR signature sources.  [12]  See also ACOUSTICS SIGNATURE CONTROL, LASER SIGNATURE CONTROL, MAGNETIC SIGNATURE CONTROL, MULTISPECTRAL SIGNATURE CONTROL, OPTICAL SIGNATURE CONTROL, RADIO FREQUENCY (RF) SIGNATURE CONTROL, and SIGNATURE CONTROL.   NOTE:  Modern warships employ diesel exhaust and gas turbine exhaust suppressors to effect infrared signature control.
INFRARED WARNING SYSTEMS - A warning system which yields automatic decisions about the state of a phenomenon based on data from observations by anINFRARED sensor and on predetermined decision algorithms. [4:6] NOTE: Infrared warning applications include: (1) detection and characterization of missile launchings; (2) detection of poisonous gases; (3) detection of nuclear detonations; (4) warning to military aircraft of ground fire, anti-aircraft missiles, or fighter pursuit; (5) terrain avoidance; (6) hazards from mines; (7) detection of hazardous levels of air pollution or of damage to the atmosphere by alien gases; (8) intrusion detection and burglar alarms; and (9) warning of a fire in a fuel tank.
INFRASOUND - NONLETHAL WARFARE measures involving very low frequency (less than 20 Hertz) sound projection to disorient, sicken or frighten people away from designated areas.  [10:2648]  Sometimes referred to as LOW FREQUENCY SOUND WEAPON.  NOTE:  Infrasound frequencies are characterized by long-range propagation and can penetrate ground and structures.  Its effects include mild to severe discomfort, organ functional disturbance (e.g., nausea), and organ disruption (e.g., bowel spasms).  [10:2748]
INSERTION LOSS - A loss resulting from the insertion of a transducer in a transmission system. It is the ratio of (A) the power delivered to that part of the system following the transducer, before insertion of the transducer, to (B) the power delivered to that same part of the system after insertion of the transducer. [3] EXAMPLE: In the case of fiber optics, the insertion loss is the total optical power loss caused by the insertion of an optical component such as a connector or splice.
INSTANTANEOUS FIELD OF VIEW - An angular area defining limits to the volume of space within which a sensor can respond instantaneously to the presence of a target.  The instantaneous FIELD OF VIEW (FOV) of an ELECTRO-OPTIC  system is limited by a field stop in the focal plane (often the field stop is the physical aperture of a modulator or detector).  The instantaneous field of view of an RF system is limited by the angular extent, or BEAMWIDTH, of the main beam of its antenna.   []
INSTANTANEOUS FREQUENCY MEASUREMENT (IFM) RECEIVER -- A SIGINT receiver which operates by splitting the incoming signal into two or more paths of differing lengths so as to generate phase differences proportional to frequency.  This type receiver simultaneously covers a wide RF bandwidth with good frequency resolution and no need for spectral scanning.  The IFM receiver, however, suffers from relatively poor sensitivity and an inability to sort simultaneous signals.  [10:2561]
INSTANTANEOUS PULSE POSITION MEMORY - An ECCM technique that requires a radar pulse to be received on two successive pulse repetition periods in the same range interval before processing and display of the radar signal occurs. [8]
INSTRUMENTED MULTISPECTRAL CUE (IMC) - An expendable replica of an actual target, such as a tank, which contains heat generators and RADAR REFLECTORS to realistically simulate both the INFRARED (IR) and radar SIGNATURES of the target.  []
INTEGRATED CIRCUIT (IC) - A combination of interconnected circuit elements inseparably associated on or within a continuous substrate. [3]
INTEGRATED CIRCUIT CARD - See SMART CARD .
INTEGRATED NAVIGATION SENSOR SYSTEM (INSS) - A compact system designed to provide very-shallow-water divers, such as SEAL teams and Explosive Ordnance Disposal (EOD) teams, with a visually enhanced sensor and precise navigation capability.  []
INTEGRATED SIGHT (IS) - A weapon or tripod-mounted sight consisting of an integrated uncooled thermal imager, eye-safe laser rangefinder, electronic compass, CCD camera and INFRARED LASER pointer.  The integrated sight provides the soldier with the ability to acquire targets during daylight, darkness, adverse weather, and through battlefield OBSCURANTS to provide target position data for indirect fire.  [10:2802]
INTELLIGENCE-BASED WARFARE (IBF) - The design and protection of systems that seek sufficient knowledge to dominate the battlespace, and the denial of such knowledge to the adversary.  []
INTELLIGENT MINE FIELD (IMF) - A rapid force projection initiative (RFPI) that uses both acoustic and seismic sensors to detect and track vehicles entering the minefield. The primary components of the IMF are the Wide Area Munition (WAM) and a Gateway Controller.  The WAM consists of three major subsystems: a communications module, a ground platform module and a smart submunition/warhead (sublet module). Once deployed, the WAM rights itself and autonomously searches for a target vehicle. When ready to fire, the WAM launches a sublet over the target, using a passive infrared sensor to detect it and firing an Explosively Formed Penetrator (EFP) at the vulnerable area.  The Gateway Controller is a two-way communication system capable of independently commanding each WAM under its control and providing the commander with battlefield information gathered from the individual WAM sensors. This enables the instantaneous construction of a detailed "picture" of enemy forces entering the minefield. The Gateway Controller employs decision-aid logic to optimize minefield operations and is capable of safely disarming WAM units, allowing for easy battlefield cleanup.  [10:2721]
INTERCEPTIBILITY - A measure of the ease with which an enemy can electronically intercept and identify signals and determine the location of a friendly electronic system. [4:13] See also VULNERABILITY, ACCESSIBILITY, and SUSCEPTIBILITY.
INTERCEPT RECEIVER - A receiver designed to detect and provide visual and/or aural indication of electromagnetic emissions occurring within the particular portion of the ELECTROMAGNETIC SPECTRUM to which it is tuned. [1]
INTERFACE - (1) As pertaining to system components: (a) A shared boundary; (b) To interact or communicate with another system component. [10:33] (2) A boundary or point common to two or more similar or dissimilar command and control systems, sub-systems, or other entities against which or at which necessary information flow takes place. [1]
INTERFERENCE CANCELING - A passive ECCM technique which samples the interference or jamming signal, modifies its amplitude to be identical to that entering the receiver, and reverses its polarity. When the two signals are electrically summed, the interference is canceled. [4:4]
INTERFEROMETER - As pertains to radar, a receiving system which determines the angle of arrival of a WAVE by phase comparison of the SIGNALs received at separate antennas or separate points on the same antenna. [3]
INTERFEROMETRIC TRIANGLE - In DIRECTION FINDING, the triangle formed by a segment of the wavefront of the signal of interest, the base line (the line connecting two antennas which can both receive the signal of interest), and a line from the antenna farthest from the transmitter to the wavefront as it reaches the closer antenna.   [10:2516]  Note:  The interferometric triangle is a right triangle with the base line as the hypotenuse.
INTERNATIONAL ATOMIC TIME (TAI) - An atomic time scale maintained by the Bureau International des Poids et Mesures, near Paris, and based on data from some 230 atomic clocks located all over the world.  [10:2623]
INTERNATIONAL SIGNAL FLAGS - Flags, pennants, and burgees which denote letters, numbers, maneuvering signals, and other information.  []  ( Visit the Flag Home Page for this Web site. )
INTERNET - (1) internet: A collection of NETWORKS connected by ROUTERS.  (2) Internet: The worldwide internet based on the TCP/IP PROTOCOL.  [10:2632]  NOTE:  The Internet is a three-level hierarchy composed of BACKBONE networks (e.g., Ultranet), mid-level networks (e.g., NEARnet), and STUB NETWORKS.  The Internet is a multi-protocol internet.  [10:2736]
INTERNET COOKIE - See COOKIE.
INTEROPERABILITY - (1) The ability of systems, units or forces to provide services to and accept services from other systems, units or forces and to use the services so exchanged to enable them to operate effectively together. (2) The condition achieved among communications-electronics systems or items of communications-electronics equipment when information or services can be exchanged directly and satisfactorily between them and/or their users. The degree of interoperability should be defined when referring to specific cases. [1]
INTEROPERATION - The use of interoperable systems, units, or forces. [1]
INTERPRETABILITY - Suitability of IMAGERY for interpretation with respect to answering adequately requirements on a given target in terms of quality and scale: a)poor imagery is unsuitable for interpretation to answer adequately requirements on a given type of target. b) fair imagery is suitable for interpretation to answer requirements on a given type of target but with only average detail. c) good imagery is suitable for interpretation to answer requirements on a given type of target in considerable detail. d) excellent imagery is suitable for interpretation to answer requirements on a given type of target in complete detail. [1]
IN-TIME INFORMATION INTEGRATION SYSTEM (I3S) - A global information net incorporating ARTIFICIAL INTELLIGENCE, NEURAL NETWORKS, and fuzzy logic to produce an advanced computer SYSTEM ARCHITECTURE for data collection, transmission, and analysis.  [10:2750]
INTRUSION - A COMMUNICATIONS JAMMING technique to confuse operators and data processing equipment. It involves the transmission of false messages on victim communication channels. [] See also ELECTROMAGNETIC INTRUSION.  NOTE:  In general intrusion is the intentional insertion of information into transmission paths to deceive or confuse the adversary.
INTRUSION DETECTION SYSTEM (IDS) - A computer system designed to detect attacks or attack preparations by monitoring either the traffic on a computer network, an application, or  operation system activities within a computer.  [10:2853]   See also ANOMALY DETECTION, HOST-BASED INTRUSION DETECTION,NETWORK-BASED INTRUSION DETECTION, PORT SCAN, SIGNATURE DETECTION.
INVENTING - A DECEPTION technique that creates something entirely new, such as rubber tanks, false radio traffic, and false orders of battle. [10:49]
INVERSE GAIN ECCM - A generic ECCM technique that degrades the effectiveness of Inverse Gain Jamming and related amplitude modulation ECM techniques. [8]Examples are SCAN-ON-RECEIVE-ONLY (SORO) and HIDDEN SCAN.
INVERTER - In electrical engineering, a device for converting direct current into alternating current. [1] Contrast with RECTIFIER.
INVERSE GAIN JAMMING - (1) A self-screening or support ECM technique for use against radars that depend upon the target return signal amplitude modulation recovery methods for data extraction. It consists of transmitting either an on-frequency noise signal or a repeated signal that has the inverse scan modulation characteristic of the victim radar antenna scan pattern. [8] (2) A jamming technique wherein the jamming power is inversely proportional to the received signal power. [10:55] Contrast withINVERSE GAIN ECCM.
INVISIBLE WEB - That portion of the Web that is made up of unindexable content that search engines either can't or won't index.   [10:2888] See also SPIDER.  NOTE: The invisible web consists largely of databases which search engines cannot access.
IONOGRAM - A display that shows the altitude of ionospherically-returned RADAR echoes as a function of frequency.  [10:2778]
IONOSPHERE - That part of a planetary atmosphere where ions and electrons are present in quantities sufficient to affect the propagation of radio waves. [3]    NOTE:  The region of the ionosphere between about 50 and 90 kilometers is called the D-layer, and is responsible for most of the daytime attenuation of LF, MF and HF radio waves.  The lowest clearly-defined ionospheric layer, called the E-layer, occurs between 100 and 120 kilometers.  The ionospheric region occurring between 150 and 500 kilometers is called the F-Layer, and is partitioned into the F1 and F2 layers.  The F2 layer has the higher ion density and is always present.  Finally, there is the sporadic E-layer, that part of the E-layer that is thin, traisient, and of limited extent.
IR CHAFF - See EMISSIVE CHAFF.
IRON HAND - See WILD WEASEL.
ISOLUMINESCENCE - A deception technique whereby the protected object generates - in the direction of the victim viewer - the same color and intensity of light as its background as seen by the viewer, so that it becomes indistinguishable from the background, and is thus invisible to the viewer. [] See also YEHUDI.
ISOTROPIC ANTENNA - A hypothetical, lossless antenna having equal radiation intensity in all directions. [3] NOTE: The isotropic antenna provides a convenient reference for expressing the directive properties of actual antennas.
________________________________________
August 20, 2001 05:05 AM -0700