JSF 'at risk' from new Russian radars

http://news.theage.com.au/jsf-at-risk-from-new-russian-radars/20080501-29yn.html

Australia's new Joint Strike Fighter (JSF) combat aircraft could be vulnerable to a Russian radar technology which appears to overcome their key stealth advantage, a defence analyst has warned.

Dr Carlo Kopp, an analyst with the defence think tank Air Power Australia, says the risk was demonstrated almost a decade ago when Serbian air defences shot down a US F-117A Nighthawk stealth aircraft.

That wake-up call evidently was not heeded in the west, he said...

Russian publications stated quite bluntly that US stealth designs had been largely optimised to defeat widely-used radars operating in the centimetric and decimetric bands, Dr Kopp said.

Such radars feature wavelengths around 10-100 millimetres, but new advanced Russian digital radars, now being actively marketed, operate in the VHF (very high frequency) band with wavelengths about two metres.

Dr Kopp said stealth technology was very effective at defeating centimetric and decimetric radar but much less so at remaining invisible to VHF radar.

An analysis of JSF suggested it was particularly vulnerable to detection by radars in this band because of its small size and particular design, he said...

Once the Russians deployed their counter-stealth radars, it was to be expected that other nations such as China would follow, Dr Kopp said...

A defence spokesman said the very low observable (VLO) stealth characteristics of the JSF, as with all stealth aircraft, were optimised for specific radar frequency bands.

"However, even outside of these optimised bands a VLO aircraft is much harder to detect than a conventional aircraft," he said...