Thursday, September 17, 2009

Beijing Is Developing Anti-Stealth Abilities



Beijing Is Developing Anti-Stealth Abilities


China is developing new radar and other sophisticated systems to find and target U.S. radar-evading stealth aircraft such as the F-22 Raptor, F-35 Lightning, F-117 Nighthawk and B-2 Spirit.

China watchers in Asia and the United States have seen an increase in China’s anti-stealth research and development, and procurement and manufacturing of passive, bistatic high frequency and long-range radars.

China’s efforts to defeat U.S. stealth technology also include espionage. From 2002 through 2005, China received sensitive data on the B-2 from Noshir Gowadia, a former Northrop Grumman engineer who helped design its exhaust cloaking system, according to FBI officials. The information likely helped China more easily detect not just the B-2, but the B-1, F-15 and air-launched cruise missiles as well.

A former U.S. defense attaché who was assigned to Beijing said China’s anti-stealth programs may seriously threaten U.S. stealth aircraft.

“I think it’s real and well within China’s reach. It’s been investing in research and development on counterstealth technologies for a decade or more,” he said.

Michael Pillsbury, a Washington-based China military specialist, said, “China has a long record of open-source advocacy writings about both the critical importance of counterstealth for China and debates about the best mix of alternative approaches China needs to develop counterstealth.”

Pillsbury said off-the-shelf technology could help in the near term. But perhaps more effective, he said, is Chinese authors’ suggestion that high-powered computers be used to gather up the extremely weak signals bounced off stealth aircraft by FM radio and TV stations.

“This system would not need new transmitters, as it could rely on the national network in this frequency range,” Pillsbury said.

Richard Fisher, vice president of the Washington-based International Assessment and Strategy Center, said China has been focused on meter-wave, passive over-the-horizon radar and infrared counters to U.S. stealth technologies. These include the acquisition of four Kolchuga passive sensor systems from Ukraine.

“At the 2001 Moscow Airshow, a Russian radar engineer responsible for upgrading old meter-wave radar with advanced computer tech complained bitterly to me that China had stolen their technology via his Balkan customer,” Fisher said. “An upgraded Russian meter-wave radar is suspected of having played a major role in the Serbian shoot-down of the F-117 stealth fighter [over Kosovo in 19990. I suspect the Yagi-antenna meter-wave radar ... benefited from this ‘research.’”

He said China began marketing a Kolchuga derivative at the 2005 IDEX International Defence Exhibition in Abu Dhabi, in the United Arab Emirates.

“The radar is a three-receiver, triangulating passive detection system that officials claimed had a 300- to 400-kilometer range, vice the 600-kilometer range of Kolchuga. Like Kolchuga, it is meant to be integrated with other sensor data to produce a better air defense picture,” he said.

The former U.S. military attaché said stealth only makes detection harder, not impossible.

“There’s nothing magical about picking up ‘stealth’ aircraft,” he said. “For active radar technology, it’s a matter of being able to pick up low radar cross-section [RCS] targets at long ranges. Need lots of power, a fairly low frequency [ultra high frequency], and large arrays or power aperture.”

The former attaché pointed to China’s interest in passive radar systems. China ordered six VERA-E systems in 2004 from the Czech Republic for $55 million, but the U.S. government successfully blocked the sale. However, the attaché said that VERA components and technical specifications were transferred to Beijing.

At the China International Electronic Exhibition in Beijing in 2006, the Institute of China Electronic Technology Corp. revealed its YLC-20 two-station passive surveillance radar, believed to be a copy of the VERA-E.

“China’s been doing a lot of work in the area of active radars operating above the HF portion of the frequency spectrum,” said the former attaché. “The other key issue to ensuring early detection of low RCS aircraft is having the radar be elevated so it can overcome line-of-sight limitations. This is where aerostats, or tethered balloons with a radar, come in.”