AN/APQ-116 radar family

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. ==AN/APN-165==

Terrain-following/ground-mapping radar by Texas Instruments for OV-1 Mohawk ==AN/APQ-89==

TFR (Terrain-Following Radar) tested on T-2 Buckeye for pilots to familiarize TFR operation on other combat aircraft. ==AN/APQ-99==

Developed by TI as a multi-modes radar, 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. ==AN/APQ-101==

Terrain-following radar by Texas Instruments. ==AN/APQ-110==

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. ==AN/APQ-115==

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. The Texas Instruments I-band AN/APQ-116 is a TFR used in A-7 Corsair II 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. ==AN/APQ-122==

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. ==AN/APQ-126==

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. This is primarily AN/APQ-116/122 incorporating improved maritime capability. Specifications: • Maritime surface search: (high altitude): 150NM • Maritime surface search: (low altitude): 106NM • Maritime surface search (vs. small contacts): 51NM • Land surface search (med altitude): 34NM • Air search: 20NM • Terrain following: 19NM ==AN/APQ-134==

Ku band terrain-following radar by Texas Instruments to replace AN/APQ-110 for F-111A/FB-111A. ==AN/APQ-139==

Ku band multi-mode radar by Texas Instruments for B-57G specially designed for night interdiction missions in Vietnam. ==AN/APQ-146==

Improved AN/APQ-134 Ku band terrain-following radar by Texas Instruments for F-111C/F. ==AN/APQ-147==

TFR (Terrain-Following Radar) for initial batch of MH-60K ==AN/APQ-154==

Improved AN/APQ-141 terrain-following radar by Texas Instruments for HH-53. ==AN/APQ-158==

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. ==AN/APQ-162==

Development of AN/APQ-99 for RF-4C, incorporating experience gained from AN/APQ-116 and other radars in the family. ==AN/APQ-168==

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. ==AN/APQ-171==

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. ==AN/APQ-172==

Improved AN/APQ-162 TFR (Terrain-Following Radar) for RF-4C. ==AN/APQ-174==

The AN/APQ-174 is an American Ku band radar used on MH-60K Blackhawk and MH-47E Chinook helicopters for navigation, particularly at low level. Developed during the late 1980s as a derivative of the AN/APQ-168 and LANTIRN radars, it was initially procured in the early 1990s. The radar can be used for a variety of missions, including combat search and rescue (CSAR) and special forces insertion and extraction. This pod-mounted radar has a variety of modes, including terrain-following and terrain-avoidance, ground mapping, air-to-ground ranging, weather detection/tracking, navigation, beacon interrogation, cross scan modes and power management. Angular scan times are 5.5º/sec and the weather mode is improved during heavy rain by the use of circular polarization. ==AN/APQ-186==