The

Emerson Electric Emerson Electric Co. is an American multinational corporation headquartered in Ferguson, Missouri. The ''Fortune'' 500 company manufactures products and provides engineering services for industrial, commercial, and consumer markets.

AN/APQ-159 was an I band/ J band

radar Radar is a detection system that uses radio waves to determine the distance ('' ranging''), angle, and radial velocity of objects relative to the site. It can be used to detect aircraft, ships, spacecraft, guided missiles, motor vehicles, we ...

designed to upgrade Emerson's simple AN/APQ-153 used in the

Northrop F-5 The Northrop F-5 is a family of supersonic light fighter aircraft initially designed as a privately funded project in the late 1950s by Northrop Corporation. There are two main models, the original F-5A and F-5B Freedom Fighter variants and t ...

. It offered roughly double the range, increased off-boresight tracking angles, and considerably improved reliability. Originally intended to be replaced by the further improved AN/APQ-167, modernized F-5s have typically moved to the entirely new AN/APG-69 instead. Like the earlier APQ-153, the APQ-159 was a purely air-to-air radar system. It had four primary modes of operation, two search modes with different ranges using a simple

B-Scope A radar display is an electronic device to present radar data to the operator. The radar system transmits pulses or continuous waves of electromagnetic radiation, a small portion of which backscatter off targets (intended or otherwise) and retur ...

display, a

C-Scope A radar display is an electronic device to present radar data to the operator. The radar system transmits pulses or continuous waves of electromagnetic radiation, a small portion of which backscatter off targets (intended or otherwise) and retur ...

gunnery display with ranging and automatic lock-on ("dogfight mode"), and a similar mode used with the

AIM-9 Sidewinder The AIM-9 Sidewinder (where "AIM" stands for "Air Intercept Missile") is a short-range air-to-air missile which entered service with the US Navy in 1956 and subsequently was adopted by the US Air Force in 1964. Since then the Sidewinder has prove ...

that calculated the missile's engagement envelope and provided cues to the pilot to fly into the envelope. The radar offered no air-to-ground modes at all, nor was it capable of firing the AIM-7 Sparrow in spite of its BVR-capable range. The APQ-159's primary upgrade was the addition of a new planar phased array antenna, replacing the -153's parabolic dish. This made the antenna smaller front-to-back which allowed it to be pointed to higher angles within the nose. It also greatly reduced the sidelobes, which improved gain and allowed the range to be greatly increased from the -153's roughly to the -159's . The electronics were also upgraded, offering increased

frequency agility Frequency agility is the ability of a radar system to quickly shift its operating frequency to account for atmospheric effects, jamming, mutual interference with friendly sources, or to make it more difficult to locate the radar broadcaster through ...

and dramatically improving

mean time between failure Mean time between failures (MTBF) is the predicted elapsed time between inherent failures of a mechanical or electronic system during normal system operation. MTBF can be calculated as the arithmetic mean (average) time between failures of a system ...

(MTBF) from about 62 hours in the -153 to 125 in the latest models of the -159, which have actually demonstrated 150 hours MTBF in the field. Several versions of the APQ-159 were built over its lifetime. It was initially offered in four separate models with the same radar electronics, but different displays. The APQ-159-1 and -2 models used a display that could operate in

television Television, sometimes shortened to TV, is a telecommunication medium for transmitting moving images and sound. The term can refer to a television set, or the medium of television transmission. Television is a mass medium for advertisin ...

mode to operate the

AGM-65 Maverick The AGM-65 Maverick is an air-to-ground missile (AGM) designed for close air support. It is the most widely produced precision-guided missile in the Western world, and is effective against a wide range of tactical targets, including armor, ...

air-to-ground missile, while the -3 and -4 lacked this capability. The -1 and -3 models had a single display, while the -2 and -4's had dual displays for use in the two seater F-5F. The APQ-159-5 version was a product improvement that further improved reliability and reduced weight to the same as the original APQ-153, making in-field upgrades much simpler. The final version was the APQ-159-7. Technologies of AN/APQ-159 have been adopted for another radar, the AN/APQ-167. This is similar to the dual-display AN/APQ-159, which thus is essentially the AN/APQ-159 equivalent of AN/APQ-157. However, the new radar was not adopted by foreign customers originally targeted, and instead, it is used on Cessna T-47A Citation by USAF for radar operator training.APQ-167 on T-47
/ref>

References

''Jane's Avionics'', July 12, 2002

External links

USDynamics AN/APQ-159
{{DEFAULTSORT:AN APQ-159 Aircraft radars Military radars of the United States Radars of the United States Air Force Emerson Electric radars