Description of the radar set, tactical-technical characteristics
Figure 1: F-16 aircraft with radar receiver and transmitter in lower section for easy accessibility
|pulse repetition time (PRT):|
|pulse repetition frequency (PRF):|
|instrumented range:||80 NM (≙ 150 km)|
|azimuth angular coverage:||±10°/±30°/±60º|
AN/APG-66 is an X-Band fully coherent pulse Doppler radar which was originally designed for use on the F-16 multirole combat aircraft in support of AN/AIM-7F/M Sparrow, AN/AIM-9L/M Sidewinder, AN/AIM-120A, Penguin, MICA and Skyflash E missiles. The radar is of modular design and comprises six functional Line-Replaceable Units (LRUs) each of which has its own power supply (Antenna, Transmitter, Low-power RF, Digital signal processor, Radar computer, Display). In total, AN/APG-66 is noted as containing 9,500 component parts and in its production form, has no associated hydraulics or rate/roll gyros. The first model was fitted with a traveling wave tube (TWT) which was later replaced by a solid-state power amplifier.
The equipment has formally demonstrated a Mean Time Between Failure (MTBF) figure of 121 hours and a meantime to repair of five minutes. The AN/APG-66 offers 10 operating modes, some of which are associated with frequency agility to resist jamming. All system functions, including self-test, are computer controlled via a serial digital databus. LRU production has involved a European consortium which included companies in Belgium, Denmark, Netherlands and Norway.
The basic APG-66 has spawned a range of variants as follows:
- AN/APG-66(V): Employed in select US Navy P-3 Orion aircraft as part of a Counter Drug Update (CDU) for Counter-narcotics (CN) surveillance and interdiction operations.
- AN/APG-66(T47) is the variant installed in the USAF’s Aeronautical Systems Center’s five Cessna OT-47B tracking aircraft. In this installation, the radar is integrated with the Northrop Grumman WF-360 Forward-Looking InfraRed (FLIR) sensor.
- AN/APG-66(V)2 is an upgrade of the basic radar which is matched to the US/NATO F-16A/B mid-life update programme.
The enhanced radar is reported to offer greater detection range (increased from 65 to 83 km in the presence of heavy clutter and jamming);
improved reliability (an MTBF figure of 210 hours); improved protection against electro-magnetic interference;
enhanced operational performance (including an improved mapping capability and a reduced false alarm rate) and the ability to support a colour display.
AN/APG-66(V)2 has the following operating modes:
- Air-to-Air: Combined search and track; Track-While-Scan (TWS); air combat search and automatic tracking.
- Air-to-Surface: Real beam mapping; 64:1 Doppler beam sharpening; scan freeze; ranging; beacon homing; sea search and combined ground-map and air target track.
- AN/APG-66(V)2A is an AN/APG-66(V)2 with a new combined signal and data processor that provides seven times the speed and 20 times the memory of the older radar computer and digital signal processor line replaceable units. In this new variant, the displayed resolution in ground-mapping mode is quadrupled, and is reported to be close to that offered by SAR techniques. Used for modernization of F-16A/B fleet of Belgium, Denmark, Norway, Portugal and the Netherlands in the mid-1990s.
- AN/APG-66(V)3 is the AN/APG-66(V)2 but with CW illumination capability, selected by Taiwan for use on its F-16A/B aircraft which is AN/AIM-7 Sparrow capable.
- AN/APG-66(V)X is an improved version of the APG-66(V)2 radar with greater detection range.
- AN/APG-66H is an AN/APG-66 variant which is optimised for use on the British Aerospace Hawk 200 single-seat multirole combat aircraft. To fit the space constraints of the Hawk installation, APG-66H features a slightly smaller antenna than the standard equipment and a new signal data processor.
- AN/APG-66NT is the APG-66 variant installed in the 17 civilian-operated T-39N aircraft which are used in the US Navy’s Undergraduate Naval Flight Officer training programme.
- AN/APG-66NZ is an APG-66 variant which is reported to incorporate a maritime tracking mode and is installed on New Zealand’s fleet of 15 A-4K and five TA-4K Kahu Skyhawks.
- AN/APG-66SR is an extended range variant of the basic radar which is used in Northrop Grumman’s Multi-Sensor Surveillance Aircraft (MSSA) system. Here, the radar is teamed with a WF-360 FLIR; a navigation subsystem which includes a Litton LTN-92 ring laser gyro inertial navigation unit and a Global Positioning System receiver. AN/APG-66SR is fitted with a larger aperture antenna and, as installed in the first MSSA platform (the Pilatus Britten-Norman BM2T-4R Defender), offers 360º coverage in azimuth.
- AN/APG-66T is an APG-66 variant which is described as offering multitarget TWS, four dogfight operating modes and situational awareness mode.