# Airborne AESA Radars



## tomahawk6 (13 Jul 2007)

http://www.military.com/NewsContent/0,13319,103141,00.html

Navy Super Hornets Get Revolutionary Radar
David Axe  |  June 28, 2006

The Navy is fielding a new fighter radar that promises to perform much better and cost less than older systems.

The APG-79 Active Electronically Scanned Array (AESA) radar, built by Raytheon, equips new two-seat F/A-18F Super Hornets being fielded to Navy Fighter Attack Squadron 213 based at Oceana, Virginia.

AESA radars are the first to abandon the basic design of all radars since World War II.

"On a conventional radar, an antenna moves back and forth, back and forth then processes information," says Raytheon manager Dave Goold. "The unique difference with AESA is that the antenna itself does not move. [Instead,] you use beams steered by a computer that tells the beams where to go look. With AESA, the antenna follows the processing" instead of vice versa, meaning it’s faster.

Whereas traditional radars rely on a single mechanical antenna, often shaped like a dish, the AESA depends on numerous tiny electronic modules that each emit a radar beam. It's like packing dozens of smart radars into one. 

"It gives you much greater range and the ability to track many more targets," Goold continues. "It nearly simultaneously allows you to do ... air-to-air and air-to-ground [modes], so you can take that array and 'split it up', if you will, [saying,] 'I want this portion to do air-to-air and this portion to do air-to-surface'."

"In a two-seat airplane [with the APG-79,] you can worry about the air-to-air and ground threats at the same time," says Navy Lt. Comm. Trenton Lennard, from the Navy's fighter readiness office. "In self-escort strike, our most high-profile mission, the AESA allows us to keep an air-to-air look all the way in. If you've got the aircrew capability, [as in a] two-seat cockpit, it's going to let us look into the sky and drop bombs at the same time."  

Beyond being faster than mechanical radars and capable of multi-tasking, the APG-79 features other advancements -- some of which mean brand-new capabilities.

"It will give you better Synthetic Aperture Radar [SAR] pictures," Goold says, referring to the APG-79's ability to map the ground using a high-resolution radar "snapshot". The radar can then tag small moving ground targets and overlay them on the SAR map, giving the aircrew a useful reference as it moves to attack. This latter capability mimics that of the Air Force's sophisticated J-STARS surveillance aircraft. 

Methods still in development might even allow Super Hornet crews to use tight AESA radar beams to transmit data such as SAR maps to other aircraft and to ground stations, improving everyone's situational awareness and turning the Super Hornet into what Goold calls “a critical node” in network-centric warfare. 

Finally, the APG-79 can use high-power radar beams to disrupt enemy electronic systems. This tactic is vital to the F/A-18G Growler, an evolved Super Hornet that is slated to replace the Navy's geriatric EA-6B Prowler electronic attack jets. 

"AESA is so advanced that we don't even have all the tactics for using it yet," Lennard says. "Our VX [test squadron] guys are flying with it and our Fleet Replacement [training] Squadrons are learning how to teach it."

Even with its advanced capabilities, the APG-79 is simpler and more robust than conventional radars.

"You no longer have moving parts," says Navy Lt. Comm. Marc Preston, also with the fighter readiness office. "Like with anything else, when you have parts that move, they wear out. With a fixed array like in the AESA, your maintainability and durability go up significantly."

"In the off chance that something does need to be repaired, it can be repaired much quicker," Goold says. "That leads to lower life-cycle costs. The AESA array itself will outlive the airplane. And it's built to allow for graceful degradation. ... Over a number of years, you will lose some of those modules, but the system can compensate for that. As a maintainer, you don't have to do any work at all [on the radar]."

The APG-79 represents a change in the way some militaries think about aircraft. In older generations of planes, the airframe was usually designed first and sensors were added later. But in the Super Hornet, the Air Force's F-22 and the forthcoming multi-service F-35, sensors drove the airframe design. 

"The vision early on with the Super Hornet revolved around maximizing sensors," Goold says.

But AESA development took longer than the Super Hornet airframe development, so several lots of Super Hornets had been built before AESA was ready. That means Raytheon will have to back-fit new radars to as many as 135 jets. Goold estimates that Raytheon will install its 415th and last APG-79 in a Super Hornet in 2013. 

Looking forward, Raytheon hopes to modernize older U.S. military aircraft with AESA radars. Talks are underway with the Air National Guard to install a larger APG-79 in air-to-air F-15Cs. And the active Air Force is considering an AESA for its ground-attack F-15Es.


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## observor 69 (13 Jul 2007)

"a number of years, you will lose some of those modules, but the system can compensate for that. As a maintainer, you don't have to do any work at all [on the radar]."

Kind of an oxymoron!   

 Oh goodie more time to pump gas and change tires.  ;D


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## peaches (14 Jul 2007)

It is already in use in active duty F15C and the F22A....  Very sweet piece of kit......


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