F/A-18 AESA - New Technology Revolutionizes Radar Benefits

Story Number: NNS020712-11Release Date: 7/12/2002 11:17:00 AM
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By Nicolette Cormier, NAVAIR Public Affairs

PATUXENT RIVER, Md. (NNS) -- The fleet can expect dramatic changes in radar operation with the introduction of the APG-79 Active Electronically Scanned Array (AESA), a wide band electronically scanned array radar for the F/A-18E/F "Super Hornet."

While fleet operators are excited about this new technology, many do not appreciate the depth of the differences between the radar in use today, and the AESA the Super Hornet and Joint Strike Fighter (JSF) will utilize.

Cmdr. Dave Dunaway, APG-79 Program Manager, said, "This is a state-of-the-art radar. In my twenty years in the US Navy, this is the first time I have seen a revolutionary leap in capability vice evolutionary.

"It's not an incremental change. It's probably got at least 10 times more capability than the APG-73 and we are doing it in less time. When compared to historical radar programs, this one is faster, cheaper and provides much more performance," Dunaway said.

Dunaway credits the program's success to the inventive acquisition strategy and the compressed timeline put together by a team of government and industry personnel. He said, "We used an innovative contracting strategy to minimize the delayed start of the program.

In the past, a program like this would not have entered Engineering and Manufacturing Development (EMD) for three years from the concept development. Because of this unique funding strategy, AESA hit EMD at full steam in February 2001, a little over a year after new start approval."

AESA's state-of-the-art technology begins with its antenna. Manufactured by the Raytheon Company, it features a tile array vice brick array and uses exceptionally innovative processor architecture. Dunaway explained, "The transmit and receive modules (TR) are very thin, about the size of a quarter.

This is the technology of the future. It's basically the same antenna that Boeing and Raytheon had proposed for the JSF, using the flip chip technology."

Testing has shown that the electronically scanned array is far superior to the mechanical scanning methodology of tracking. With mechanical tracking, the radar tracked while scanning, taking up a fair amount of time and reducing track accuracy.

The electronically scanned array uses a "search while track" methodology that significantly improves track quality of multiple targets with little or no degradation of the search capability of the radar.

The new array searches while it tracks the target on a need-to-track basis, giving a much better multiple target track capability. Although it still takes time to go through the volume with electronic scanning, once the target is found within that volume, the radar automatically schedules periodic look backs keeping track of the target at a much higher level of fidelity and frequency than a mechanically scanned antenna.

Furthermore, this AESA has a more powerful radar. Detection ranges will be significantly better than the current APG-73 radar, giving the pilot a tactical range advantage. This brand new radar shows more targets at a much higher fidelity, which provides the pilot more time to accomplish other tasks, as well as the ability to scan air-to-air and air-to-ground in a near simultaneous fashion.

In the air-to-ground arena, the improved detection range has resulted in higher resolution Synthetic Aperture Resolution (SAR) maps that are at a higher resolution than the current capability. The aircrew can see minute runway details on the map and can identify aircraft. The new AESA provides very high-resolution maps at a range further than possible with the lower resolution APG-73 map.

"This radar will change the way we do business," said Dunaway. "We are currently limited by the radar's ability to detect air-to-air targets at range. In other words we have to wait and let the radar catch up before we can shoot the missile.

With the AESA we'll be able to shoot the missile even before the target comes within the missile's range. The APG-79 radar has been designed to enable the aircrew to detect and process the target, well before it enters the maximum range of the Super Hornet's air-to-air missiles, allowing missile launch at maximum range. "

The array is situated in the nose of the airplane and each of the TR modules on the array is essentially an individual radar that transmits and receives. Once the information is received by the array, it enters the common integrated sensor processor where it is converted to tactically useful information and displayed to the aircrew. The radar then send commands back to the processor where they are converted to additional tasks for the radar to perform.

From a maintenance standpoint, the antenna is projected to have reliability that's longer than the life of the airframe. In addition, the processors are no longer replaced at the box level. Repair is easy; maintenance personnel open the box and pull a card out. This philosophy has eliminated the need to spare good cards within a Weapons Replaceable Assembly (WRA) when only one card is bad.

The Super Hornet has a reduced radar cross section technology (stealth) incorporated into its design. A traditional mechanically scanned array counters that capability and increases the effective radar cross section of the aircraft.

AESA allows the aircrew to enjoy the radar cross-section improvements on the aircraft without adversely impacting weapon system performance. Situated in the nose of the airplane, the AESA communicates through the fibre channel interface of the airplane, transmitting a huge amount of data through the advanced mission computers, into the new displays. All of this information flows freely between the radar, the Advanced Mission Computers (AMCs) and advanced displays via a fibre channel network within the airplane.

This is the first state-of-the-art fibre channel bus to be installed in a Navy tactical fighter and it represents another leap in capability and growth potential. This new architecture paves the way for tremendous AESA growth capabilities in Electronic Warfare and makes an AESA equipped Super Hornet a prime candidate for the Advanced Electronic Attack (AEA) aircraft.

In addition to all of the modifications directly associated with the radar, there have been extensive modifications to the aircraft to support the AESA. Because of the tremendous power generated and the multitude of processors required, two new heat exchangers were added to the aft end of the airplane. These new heat exchangers have enhanced the liquid cooling capacity of the aircraft significantly, and have provided the radar the essential cooling required.

Dunaway summed up the timeline. "We started the program with a year of contractor development in the primary development phase under a unique advanced agreement that got us through a Preliminary Design Review (PDR). In February of 2001, we kicked off EMD and conducted a Critical Design Review (CDR) by December of 2001. It is very unusual for a program this complex to progress so quickly. Since CDR, the program has been focusing on producing EMD hardware that is being delivered to the laboratories for hardware development, software development and weapon system integration.

Following the laboratory development phase, an extensive flight test program with the AESA radar installed in the Super Hornet will be conducted to ensure that the total system performance meets or exceeds the performance required in the projected threat environment.

The AESA radar is a revolution, not an evolution for the Super Hornet and will make this airplane one of the most capable and desired aircraft on the battlefield.

For more information concerning the U.S. Navy's AESA Radar or the F/A-18 Program, contact Denise Deon Wilson at 301-481-6263 or visit our web site at http://pma265.navair.navy.mil.

For more information about NAVAIR, go to www.navair.navy.mil. For more Naval Air Systems Command news, go to www.news.navy.mil/local/NAVAIR.

F/A-18E Super Hornet with SHARP Pod attached.
Official U.S. Navy file photo of an F/A-18E/F "Super Hornet."
June 28, 2002
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