AN/APQ-116 is one of the most numerous terrain-following radars (TFRs) produced in the world, and with over 500 units built, it was a member of a family of TFRs consisted of nearly two dozen models, all of which are based on the same general design principle. First developed by Texas Instruments, and later produced by Raytheon when the latter purchased the radar business of the former. [1]
This is the first terrain-following radar for use on crewed aircraft, designed by Bert Bechtel, a former Navy engineer, who had designed a radar scan template control technique that permitted safe aircraft descent in adverse weather. The concept was the basis of winning a $750,000 US Army contract to develop a radar system to automatically guide a drone aircraft. The US Army did not pursue the project to production, but the US Air Force became interested and believed that Bechtel's innovation would protect the low-flying planes. [2]
Terrain-following/ground-mapping radar by Texas Instruments for OV-1 Mohawk [1]
TFR (Terrain-Following Radar) tested on T-2 Buckeye for pilots to familiarize TFR operation on other combat aircraft. [1]
Developed by TI as a multi-modes radar, [2] in addition to terrain avoidance and terrain-following modes, and AN/APQ-99 can also be used for ground mapping. Smaller in size then the Westinghouse AN/APQ-72 and fitted in the nose of for A-7A, RF-4B/C. AN/APQ-99 is also supplied to Germany, Iran and Japan.
Terrain-following radar by Texas Instruments. [1]
Ku band terrain-following radar by Texas Instruments for General Dynamics F-111A and RF-4C. It replaced the side-looking mapping radar by Goodyear Tire and Rubber Company on RF-4C. [1]
Improved AN/APQ-110 terrain-following radar by Texas Instruments for the A-7A, General Dynamics F-111, RF-4C, and C-130E. AN/APQ-115 has a single contoured, spoiled parabola antenna, with a search cone of 5 degrees wide, spanning from +7 degrees above to -18 degrees below to the boresight of the aircraft. AN/APQ-115 suffered from inaccurate references (poor stabilization and Doppler inputs), which directly lead to the development of more advanced system such as AN/APQ-122. [3]
The Texas Instruments I-band AN/APQ-116 is a TFR used in A-7 Corsair II [1] and C-130 Hercules aircraft. AN/APQ-116 was basically the integration of previously independent AN/APQ-115 TFR into the ILAAS digital navigation system. The radar also fed a digital weapons computer which made possible accurate delivery of bombs from a greater stand-off distance, greatly improving survivability compared with faster platforms such as the F-4 Phantom II.
X band multi-mode radar by Texas Instruments for C-130 Hercules, Boeing RC-135, Boeing T-43 and Boeing E-4. AN/APQ-122 has a slotted planar array antenna with a separate X-band receiver used to generate MRI video, with a search cone of 7.5 degrees wide, spanning from +8 degrees above to -17 degrees below to the boresight of the aircraft. For AN/APQ-122(V)B, the stabilization reference could either be manually or automatically switched to MD-1 gyro if the LN-15J inertial navigational system become unreliable or inoperable, thus terrain following operation can still continue, where in earlier system such as AN/APQ-115, if the Doppler fails, the terrain following operation would be discontinued. [1]
60 kW improved AN/APQ-116 J band terrain-following radar by Texas Instruments for A-7D/E AC-130 and CH-53 Sea Stallion. [4] This is primarily AN/APQ-116/122 incorporating improved maritime capability. Specifications: [5]
Ku band terrain-following radar by Texas Instruments to replace AN/APQ-110 for F-111A/FB-111A. [1]
Ku band multi-mode radar by Texas Instruments for B-57G specially designed for night interdiction missions in Vietnam. [1]
Improved AN/APQ-134 Ku band terrain-following radar by Texas Instruments for F-111C/F. [1]
TFR (Terrain-Following Radar) for initial batch of MH-60K [6]
Improved AN/APQ-141 terrain-following radar by Texas Instruments for HH-53. [1]
Improvement of AN/APQ-126 with 15 line replaceable units for the MH-53 Pave Low helicopter and PAVE LOW III requirement. Designed to perform terrain following mode/function in high clutter area such as in cities. [1]
Development of AN/APQ-99 for RF-4C, incorporating experience gained from AN/APQ-116 and other radars in the family. [1]
Multi-mode radar by Texas Instruments for HH-60D & MH-60K. Increased jamming resistance, improved weather penetration, better guidance in turn flight, and better power management function in semi-covert mission. The radar can operate in terrain-clearance, terrain-avoidance, air-to-air ranging and cross-scan modes, the latter combining ground-mapping or terrain-avoidance with terrain-following. A terrain storage facility permits the radar to have a reduced duty cycle, thereby reducing the probability of detection by enemy ESM equipment. There's also the incorporation of built-in test (BITE) provides a high degree of fault isolation and detection. [1]
Improved AN/APG-146 terrain-following radar by Texas Instruments for F-111C/F, developed by Texas Instruments in the mid- eighties with the objective of replacing the four different TFR models used across the USAF F-111 fleet with a single type. While the old TFR had an MTBF around 20 hours, MBTF for the AN/APQ-171 is better than 50 hrs. [1]
Improved AN/APQ-162 TFR (Terrain-Following Radar) for RF-4C. [1]
Ku band terrain-following radar by Texas Instruments part of AN/AAQ-13 [1]
The General Dynamics F-111 Aardvark is a retired supersonic, medium-range, multirole combat aircraft. Production models of the F-111 had roles that included attack, strategic bombing, reconnaissance and electronic warfare. Aardvark comes from a South African animal that has a long nose and hugs the terrain. It is an Afrikaans word that translates literally as "earth pig" — hence the aircraft's "Pig" nickname during its Australian service.
The Sikorsky MH-53 Pave Low series is a retired long-range special operations and combat search and rescue (CSAR) helicopter for the United States Air Force. The series was upgraded from the HH-53B/C, variants of the Sikorsky CH-53 Sea Stallion. The HH-53 "Super Jolly Green Giant" was initially developed to replace the HH-3E "Jolly Green Giant". The U.S. Air Force's MH-53J/M fleet was retired in September 2008.
Terrain-following radar (TFR) is a military aerospace technology that allows a very-low-flying aircraft to automatically maintain a relatively constant altitude above ground level and therefore make detection by enemy radar more difficult. It is sometimes referred to as ground hugging or terrain hugging flight. The term nap-of-the-earth flight may also apply but is more commonly used in relation to low-flying military helicopters, which typically do not use terrain-following radar.
The AN/APQ-181 is an all-weather, low probability of intercept (LPI) phased array radar system designed by Hughes Aircraft for the U.S. Air Force B-2A Spirit bomber aircraft. The system was developed in the mid-1980s and entered service in 1993. The APQ-181 provides a number of precision targeting modes, and also supports terrain-following radar and terrain avoidance. The radar operates in the Ku band. The original design uses a TWT-based transmitter with a 2-dimensional passive electronically scanned array (PESA) antenna.
The AN/APQ-174 is an American Ku band radar used on military helicopters for navigation, particularly at low level.
The General Dynamics–Grumman EF-111A Raven is a retired electronic-warfare aircraft designed to replace the EB-66 Destroyer in the United States Air Force. Its crews and maintainers often called it the "Spark-Vark", a play on the F-111's "Aardvark" nickname.
The AN/APG-76 radar is a pulse Doppler Ku band multi-mode radar developed and manufactured by Northrop Grumman.
The Nanchang Q-6 is a cancelled ground attack aircraft of the People's Republic of China (PRC), with the Nanchang Aircraft Factory as the prime contractor. The project never went beyond the prototype stage, despite a prolonged development.
The Bars (Leopard) is a family of Russian all-weather multimode airborne radars developed by the Tikhomirov Scientific Research Institute of Instrument Design for multi-role combat aircraft such as the Su-27, Su-30 and the MiG-29.
The Emerson Electric AN/APQ-153 was an I band radar system developed for the Northrop F-5E fighter aircraft. Required to fit into the tight confines of the originally radar-less F-5, the system offered relatively simple air-to-air modes and a short detection range. The AN/APQ-157 was a similar system with dual displays and controls for the twin-seat F-5F trainer. Many of the F-5s still flying have been upgraded to the improved AN/APQ-159.
The Emerson Electric AN/APQ-159 was an I band/J band radar designed to upgrade Emerson's simple AN/APQ-153 used in the Northrop F-5. 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.
The AN/APG-67 is a multi-mode all-digital X band coherent pulse doppler radar originally developed by General Electric for the Northrop F-20 Tigershark program of the early 1980s. It offers a variety of air-to-air, air-to-ground, sea-search and mapping modes, and compatibility with most weapons used by the US Air Force in the 1980s.
The General Dynamics F-111C is a variant of the F-111 Aardvark medium-range interdictor and tactical strike aircraft, developed by General Dynamics to meet Australian requirements. The design was based on the F-111A model but included longer wings and strengthened undercarriage. The Australian government ordered 24 F-111Cs to equip the Royal Australian Air Force (RAAF) in 1963, but the aircraft were not delivered until 1973 because of long-running technical problems. During 1979 and 1980 four of these aircraft were converted to the RF-111C reconnaissance variant. Four ex–United States Air Force (USAF) F-111As were purchased by Australia and converted to F-111C standard in 1982 to replace F-111Cs destroyed during accidents. Australia also operated 15 F-111Gs between 1993 and 2007, mainly for conversion training. The RAAF retired its remaining F-111Cs in December 2010. In Australian military and aviation circles, the F-111 Aardvark was affectionately known as the "Pig", due to its long snout and terrain-following ability.
The Royal Australian Air Force (RAAF) operated 24 McDonnell Douglas F-4E Phantom II fighter-bomber aircraft in the ground attack role between 1970 and 1973. The Phantoms were leased from the United States Air Force (USAF) as an interim measure owing to delays in the delivery of the RAAF's 24 General Dynamics F-111C bombers. The F-4Es were considered successful in this role, but the government did not agree to a proposal from the RAAF to retain the aircraft after the F-111s entered service in 1973.
The AN/APQ-120 was an aircraft fire control radar (FCR) manufactured by Westinghouse for the McDonnell Douglas F-4E Phantom II. AN/APQ-120 has a long line of lineage, with its origin traced all the way back to Aero-13 FCR developed by the same company in the early 1950s. A total of half a dozen FCRs were tested and evaluated on the first 18 F-4s built, but they were soon replaced by later radars produced in great numbers, including AN/APQ-120.
The General Dynamics F-111K was a planned variant of the General Dynamics F-111 Aardvark medium-range interdictor and tactical strike aircraft by General Dynamics, to meet a Royal Air Force requirement for such an aircraft.