Guy Norris/LOS ANGELES
Teledyne Ryan Aeronautical's Global Hawk unmanned aerial reconnaissance system has demonstrated the ability to collect and transmit synthetic aperture radar (SAR), electro-optical (EO) and infrared (IR) imagery in near real time, in a flight which marked the first use of all three sensors on the same mission.
The test flight on 22 January coincided with news of the cancellation of the stealthy Lockheed Martin/Boeing DarkStar unmanned aerial reconnaissance vehicle. The move, forced on the USAF by budgetary pressures, is expected to result in an enlarged role for the Global Hawk.
Teledyne Ryan says: "The missions for each were defined as complementary, but different. DarkStar had penetration capability while we were stand-off. It could carry either IR or EO, but not both, so clearly Global Hawk can do a fair amount of what DarkStar was supposed to do - but not everything".
Both programmes were managed by the US Department of Defense Reconnaissance Systems Program Office of the USAF Aeronautical System Center. The January test flight was the fourth mission performed by air vehicle number two, and was the 10th Global Hawk flight in total. During the 6h 24min sortie, the aircraft collected three SARs, 21 EOs and two IR scenes.
The flight was a key test for the integrated sensor suite, developed by Raytheon System's Sensors and Electronic Systems division.
Raytheon's Global Hawk programme manager, Jack Conrad, says: "Our first flight included using the SAR in its mapping mode as well as the IR and EO in spot mode. Our goal is to get to 1.1m and we are either at, or very close to that."
The X-band radar is supplemented by a mid-wavelength IR sensor with a 3.6-5 micron, indium-antimonide staring focal plane array with 480 x 640 detector elements. "We got IR imagery down, although it was not as spectacular. But we were able to see targets," says Conrad.
The images from the EO system, which incorporates a 0.4-0.8 micron wavelength 1,024 x 1,024 staring focal plane array, proved particularly good, says Conrad. The Global Hawk collected images of targets at the nearby China Lake Naval Weapons Center, 18km away. "It could clearly distinguish F/A-18s and you could see their canopies. Given that we'd never even flown this sensor this was a major success."
The next flight, around 18 February, will test the SAR in spot mode, and the EO and IR in wide area search. A subsequent flight in early March is expected to see the first attempt at testing the SAR ground moving target indicator.
Source: Flight International
