Northrop Grumman has generated synthetic aperture radar maps using the Lockheed Martin F-22A Raptor's active radar array, demonstrating a key component in the US Air Force's campaign to assert the future relevance of the imperilled stealth fighter.
Adding a SAR mode is part of the Raptor Increment 3.1 upgrade programme, which converts the F-22's air-to-air APG-77 radar into an dual-mode target tracker. Northrop confirms system level integration will start in mid-year, with a flight-test phase for the improvements in 2009.
The USAF added the air-to-ground radar mode in 2003, briefly renaming the Raptor the F/A-22. The "A" was dropped by incoming chief of staff Gen Michael Moseley in 2005.
Northrop demonstrated the new SAR feature of the multimode APG-77(V)1 on board the company's BAC One-Eleven testbed aircraft.
"This is a hugely significant event for the F-22 programme because it ensures Raptor pilots will have access to critical detailed information about air and ground threats before the enemy's radar ever detects the F-22," says Teri Marconi, Northrop's vice-president of combat avionics systems.
The F-22A is in a budget battle between the USAF and the Department of Defense leadership. Washington's budget request for fiscal year 2009 seeks no money to continue F-22 production into FY2010, but also has no money to shut down Lockheed's production line. Air force leaders vow to uphold the service's requirement to buy 380 F-22s - 197 more than ordered so far. Without continued funding, the F-22 line will close by the end of FY2009.
Source: Flight International
