AN/APG-68

The New Standard

For Fighter Radar
Beyond Visual Range Expanded Air-to-Surface Growth Potential
Missile Compatibility Mission Capability
To fully utilize the AMRAAM missile To better accomplish the surface attack Growth potential is accomplished
launch envelope, radar range is greatly portion of its dual mission, the F-16C/D is through software changes or additional
extended; track files are opened and being provided with a higher resolution hardware modules with little impact on,
maintained on multiple targets; and the pi- (64:1 DBS) ground map for improved or modification to existing equipment.
lot is visually presented with a real-time navigation and bombing. The capability to The radar is designed to allow pulse
assessment of the tactical situation. detect and track both stationary and mov- doppler illumination for AIM-7F/M (Spar-
ing surface targets has also been added. row) missiles and CW illumination for
compatibility with earlier AIM-7 versions
and Skyflash missiles. Additional growth
modes include automatic terrain
following/terrain avoidance and high
resolution synthetic aperture (SAR)
mapping.

Functionally Modular Radar

The modularity of the AN/APG-66 allows The AN/APG-68 consists of four functional
radar capabilities to be upgraded within line replaceable units (LRUs): the pro-
the same system architecture. Through a grammable signal processor (PSP), the
unique technology insertion program, dual-mode transmitter (DMT), the modular
Westinghouse has evolved a new radar low-power RF (MLPRF), and the antenna.
for the F-16 to counter a rapidly changing Each LRU has its own self-contained
threat environment, while maintaining es- power supply, and is organized for auton-
sentially the same form and volume. The omy, logical function, minimum inter-
radar improvements are accomplished connection, and ease of maintenance. A
with minimum aircraft impact making digital multiplex bus system provides
retrofit into earlier model F-16s possible. "party-line" communications between the
radar computer and the other LRUs. All
radar LRUs are mounted in the nose of
the F-16 aircraft and are accessible from
ground level.
Antenna Dual-Mode Transmitter

The planar array antenna, gimballed in The AN/APG-68 radar provides the equiv- transmit power is kept constant regardless
two axes, provides high gain and very low alent of two separate radar transmitters for of waveform duty cycle without pulse
sidelobes over all scan angles. The bal- long-range as well as all-aspect target de- compression complexity or losses. DMT
anced electric drive system is lightweight, tection. The new transmitter incorporates features:
highly reliable, and easily maintained. The a dual-mode traveling wave tube, a solid-
AN/APG-68 antenna is basically the same state grid pulser, high-voltage power sup-
Air-cooled transmitter
design as the AN/APG-66 with specific plies and regulators, and protection and
improvements for tracking accuracy and control circuitry. The dual-mode transmit- Self-contained liquid cooling of TWT loop
reliability. ter (DMT) furnishes: low peak power/high for higher reliability
duty cycle for long-range intercepts; Solid-state grid pulser for improved
medium PRF waveforms with high peak maintainability
power for all-aspect intercepts; and low
PRF for air-to-surface modes. Average Microprocessor to facilitate frequency
agility and reliable self-calibration and test

LRU-1 Antenna LRU-3 Transmitter

AN APG-68 Radar Parameters

Volume: 4.5 ft3 (0.1273m3)

Weight: 394 lb (178.7 kg)
Frequency: X-band
Reliability: 70-hour Field MTBF
Maintenance: 30-minute flightline MTTR
Electronic Parts: 15,677
Cooling: Air 22 Ib/min
Input Power: 8232 VA, 400 Hz, 47 Wdc
Range Scales: 10, 20, 40, 80, 160 nmi
Elevation Coverage: 1, 2, 3 or 4 bar
Antenna Azimuth Scan ±10, ±25, ±30,
±60 degrees

LRU-2 Modular Low-Power RF LRU-4 Programmable Signal Processor

Modular Low-Power RF

The current AN/APG-66 low-power RF is The most advanced coherent frequency

replaced with a modular low-power RF generation and microwave processing
(MLPRF) for improved performance, re- capability available.
liability, maintainability, and growth po-
Higher speed data sampling for improved
tential. By using the same coherent fre-
range resolution.
quency source developed for the U.S.
Army's SGT. York Division Air Defense Improved ECCM capabilities.
Gun System, advanced capability has Improved self-test features for reduced
been achieved at substantially reduced fault isolation complexity.
costs. Modular low-power RF features:
Growth capability on a modular, plug-in
basis.
Air-to-Air Attack Range While Search Track While Scan

The AN/APG-66 has helped the pilot to A medium-PRF waveform is employed to The radar will automatically track up to ten
detect, track, and engage targets by pro- detect all-aspect targets at greatly in- targets, while displaying ten additional
viding modes useful at all aspects and creased ranges. A proven multiple-PRF search targets. This mode will allow simul-
altitudes. Those same capabilities, with processing algorithm helps ensure reliable taneous launch of AMRAAM missiles at
added performance, are inherent in the target visibility and very low false alarm multiple targets. Both manual and auto-
AN/APG-68 and are complemented by the rates. matic management of TWS target files are
addition of many new modes. provided and are available at pilot
discretion.

Velocity Search

The AN/APG-68 utilizes a high-PRF wave-

form to detect long-range head-on targets
in velocity and azimuth.

Track Range Velocity Uplook

While While Search Search
Scan Search

Programmable Signal Processor Within the PSP, a computer controls radar Uplook Search
LRUs, while an array processor performs
The programmable signal processor (PSP) the high-speed signal processing. PSP
Useful against targets above the horizon,
combines the functions of digital signal features: this mode provides maximum detection
processing and radar control in a single range capability in a clutter-free environ-
line replaceable unit. The PSP provides Program Memory: 512K words, BORAM- ment.
programmable real-time processing and stored, electronically alterable
an unparalleled degree of flexibility and Random Access Memory (RAM): 96K
growth without hardware impact. Utilizing words Raid Cluster Resolution
Westinghouse developed solid-state Block
Oriented Random Access Memory Dual-CPU computer compatible with fail-
(BORAM), the PSP has non-volatile stor- safe requirements for TF/TA By focusing on the region about a tracked
age of programs and permits field up- Processor Bulk Memory: 128K words target, special signal processing tech-
grade of software configurations without niques can provide radar separation and
Higher Order Language: JOVIAL J-73 discrimination of targets in a tight
removal or modification of hardware.
MIL-STD-1750A instruction set formation.
Air-To-Surface Attack Improved Doppler Beam Sharpened Ground Track Modes
Map
Although today's AN/APG-66 radar pro- Enhanced azimuth resolution is achieved Ground moving target indication/tracking
vides fixtaking and air-to-surface ranging through the use of two Doppler Beam modes allow radar tracking of slow speed
allowing bombing accuracy never before Sharpening (DBS) modes. An 8:1 beam targets. For large discrete targets, such
achieved in a tactical fighter, it is gener- sharpening mode is available for targets as buildings, a Fixed-Target Track (FTT)
ally against stationary targets that can that lie between 5 and 60 degrees off the mode provides accurate range, bearing,
also be visually acquired. The AN/APG-68 aircraft's velocity vector. For more precise and elevation during the target run and
offers a mode complement that enables location of targets or offset aim points that minimizes dependence on inertial navi-
successful radar navigation, target ac- fall between 15 and 60 degrees off the gation set accuracy.
quisition, and engagement of both fixed velocity vector, a 64:1 beam sharpening
and moving targets in all weather mode permits recognition and accurate
conditions. designation of tactical targets in all
Among the modes are improved doppler weather conditions.
beam sharpened map and ground track
modes.

Ground Moving DBS Fixed Target Track Ground Moving Target Indication
Target Track

Multifunction Display

The Multifunction Display (MFD) replaces

the Radar Control Panel (RCP). The MFD
in the cockpit is used by the pilot to
command the desired radar channel,
mode, range scale, scan width, and ele-
vation bar scan. The avionics system can
also assume control of the radar func-
tions, depending on the weapons and/or
delivery mode selected.
THE AN/APG-66, The Fighter Pilot's Radar
Since its operational debut in 1979, the
AN/APG-66 fire control radar has established new
standards by which all other fighter radars are
judged. Providing capabilities previously un-
available to the fighter pilot, the AN/APG-66 has
proven its performance, reliability, and main-
tainability under the most severe real world oper-
ational conditions.
In service today with the U.S. Air Force and sev-
eral allied nations, the AN/APG-66 has achieved a
long list of accomplishments:

Combat proven . . . with distinction.

Over 1,500 production deliveries in the first 5 years
of production.
Field Mean Flight Time Between Failure (MFTBF) of
70 hours . . . 38 sorties between failures.
Radar mission availability exceeding 95%.
Software updates ensure that radar capabilities
match the latest threats and tactics.

Operational Capability to
Meet Threats . . . Now and in the Future
The success of the AN/APG-66 today is AN/APG-66 now in service. Major oper-
an indication of the radar's flexibility. Be- ational improvements of the AN/APG-68
cause threats, weapons, tactics, and mis- include extended range, missile, and
sions are constantly changing, West- growth capabilities.
inghouse is engaged in a full scale de- In addition to new operational capabilities,
velopment and production program to a key AN/APG-68 program feature is an
augment the F-16's radar for continued innovative Reliability Incentive Program
superior performance. (RIP). This Reliability Incentive Program
The result of this development is the allows Westinghouse and the U.S. Air
AN/APG-68 radar which will be installed in Force to share savings in logistics support
all F-16 C/D aircraft. The new AN/APG-68 costs if contractual thresholds of oper-
provides all of the air-to-air and air-to- ational reliability are met or exceeded.
surface capabilities of the successful
In everything we do, Westinghouse is
more than 100,000 people around the
world dedicated to quality and
excellence.

You can be s u r e . . .
if it's Westinghouse

Avionics Division
Box 746 MS 235
Baltimore, Maryland 21203 USA
Telephone (301 )-765-2057
TWX: 710-862-0100
Telex: 87-828
This material has been
cleared for public release
in accordance with DoD
regulations.
 Doppler Beam Sharpening
Multimode Radar Mapping Versatility DBS Technique

The Westinghouse AN/APG-68 Fire These modes have been mechanized The DBS technique of dividing a radar
Control Radar for the F-16C/D aircraft is to allow the pilot the ability to map a beam into synthetic Doppler beams
a multimode radar with four ground target area, or navigation fix in selective and then integrating the returns into a
mapping modes available within its air- steps from large scale general area map display, greatly improves azimuth
to-surface menus. Included in its recognition to small scale high resolution and allows pinpoint
improved air-to-surface mission resolution identification of a particular designation of tactical targets in all
capabilities are Real Beam Ground target. weather conditions. In addition, DBS
Mapping, Expanded Real Beam Ground The higher resolution of the 64:1 enhances navigation.
Mapping, 8:1 Doppler Beam Sharpening, Doppler Beam Sharpening (DBS) mode
and 64:1 Doppler Beam Sharpening provides the pilot with an enhanced all-
modes. weather, night, ground target identification
and weapons delivery map.

DOVER AFB

Mapping Mode 8:1 DBS

64:1 DBS Aerial Photo

 Doppler Beam Sharpening
OCEAN CITY, MARYLAND

Chart A Chart B

Mapping Mode 8:1 DBS

64:1 DBS Aerial Photo