Six Air Force F-35A Joint Strike Fighter aircraft are currently at Edwards Air Force Base, Calif., to test the aircraft's stealth and sensor technologies against representations of Russian, Iranian and Chinese air-defenses. 

"The surface threat is a tough problem because it is a system of systems and the emerging threats that we have right now can see you hundreds of miles away. If the missile is big enough it can shoot you from hundreds of miles away," said Thomas Lawhead, operations lead for JSF integration office. "If you have stealth as you go in all those ranges shrink down. Hopefully they shrink down enough to where you can get in and launch a weapon without being seen."

He explained that the most advanced sensors have pivoted from European-based systems to ones in Asia developed by China.

"If you look back to 2001 when the JSF threat started, the threats were mostly European centric -- Russian made SA-10s or SA-20s. Now the future threats are looking at more Chinese-made and Asian made threats," he said. 

The JSF's so-called sensor fusion is designed to provide pilots with a range of integrated combat-relevant information in real time. 

"Part of what feeds the fusion is a database of airborne threats -- enemy threats and surface to air threats so that when the aircraft sees something on radar or sees a radar beam from another aircraft or missile radar -- it can categorize what it is whether it is a friend," Lawhead said. 

Unlike an F-15 or F-16 where pilots look through a heads up display, in a JSF air speed, ranges, and targeting information are displayed on a pilot's helmet visor, said Col. Carl Schaefer, the Air Force's top JSF integration official. 

One of the technologies involved in this sensor fusion is a Distributed Aperture System 360-degree sensor, a series of six electro-optical sensors designed to provide awareness and threat indications.

Another key piece of the equation is a targeting system called Electro-Optical Targeting System, or EOTS, which provides air-to-ground and air-to-air targeting with forward looking infrared and infrared search and track technology, according to Lockheed Martin. 

Furthermore, the JSF's Active Electronically Scanned Arrays, or AESA's, the aircraft is able to provide a synthetic aperture rendering of air and ground pictures. The AESA also brings the F-35 electronic warfare capabilities, Schaefer said. 

Overall, the Air Force plans to buy 1,763 JSF F-35A multi-role fighters.  So far, 42 F-35As have been delivered. 

"It brings an unprecedented sensor fusion with the radar and its optical capabilities, its data link capabilities and its radar warning receiver capabilities. It's going to be our multi-role fighter for the Air Force and provide close-air support missions, offensive counter air, defensive counter air, suppression of enemy air defenses and the destruction of enemy air defenses," Schaefer said. 

One analyst said defeating enemy air defenses involves a blend of technologies and tactics which the JSF is well-suited to perform.  

"The F-35 is low observable against enemy radar. It is also designed to emit a lot less. A big part of this is knowing where the threats are and how to avoid them. The objective is to try to fly between the cracks and gaps," said Richard Aboulafia, Vice President of analysis at the Teal Group, a Virginia-based consultancy. 

-- Kris Osborn can be reached at Kris.Osborn@monster.com.