TALKING RADARS

New radars are becoming sophisticated radios--radios that can be used as weapons against insurgents.

A series of experiments is turning the radars of next-generation tactical aircraft--including the F/A-22 and F-35--into advanced communications devices for intelligence-gathering, reconnaissance and strike missions.

Laboratory tests by Northrop Grumman and L-3 Communications researchers show new active electronically scanned array (AESA) radars can be modified to send and receive large amounts of information at high data rates. So new-generation fighters not only should be able to collect large amounts of intelligence and targeting data, but also may be able to whip those large packages of information around the battlefield in seconds instead of tens of minutes required by current data links.

These tests add communications as yet another role for the AESA radar that is already being pitched as a multifaceted surveillance device, electronic jammer and directed-energy weapon (AW&ST Sept. 5, p. 50). It also means that the F/A-22 aircraft will immediately have a key role in network-centric warfare and in the future could be able to affect enemy communications by collecting their signals and inserting false or confusing data into those networks as the forward-most elements in an information war.

While not part of this test program, Air Force planners expect to use the stealth aircraft's very sensitive and extensive receiver arrays to both gather and exploit electronic and communications intelligence. Some companies are already eyeing worms, viruses and other algorithms as cyber-weapons that can be released by stealthy manned and unmanned aircraft that can penetrate air defenses to monitor enemy electronic activity at close range (AW&ST Oct. 24, p. 49).

The company wants to conduct flight demonstrations within 12 months on a corporate test aircraft, says Joseph J. Ensor, vice president of combat avionics for Northrop Grumman Electronic Systems. Using company research and development money, scientists demonstrated high-data-rate, broadband communications using the AESA radar designed for the F/A-22. They say the capability-- primarily the result of waveform and software modifications, not hardware changes--can be made to virtually any AESA radar.

For the testing, an F/A-22, third-generation APG-77 radar is linked to an L-3 software programmable modem that turns the AESA on low-observable aircraft into a data link without disturbing the stealth fighter's signature, says Bruce Carmichael, L-3's vice president of Air Force programs. Air Force officials have emphasized that they want to exploit the fact they can get close to sensitive targets to both avoid detection and pick up low-power electronic signals. One target set includes hand-held, wireless communications devices.

"I don't see why we couldn't take something [collected] from another sensor and run it through this aperture," says Ensor. "We're taking what's in the cockpit and making it available for the whole battlefield. As long as we can get it to the right place in the jet, we can move any data offboard. It doesn't have to be data we collected."

Carmichael agrees. "From the communications standpoint, data is data. We don't really care."