Stealth technology uses four techniques to hide a target. First one is obvious. Camouflage; make the target black then run at night. Secondly, diffuse the heat signature of the target so no passive infrared seeking systems can 'see' it. You can't measure speed with these passive systems very accurately though, which is why plod doesn't use them. You need to use an active system (transmits a signal, look for reflection) to determine the speed of a target accurately.
In order for a radar or laser based system to clock the target it needs to be able to get a reflection from the target. The difference between the frequencies of the outgoing signal compared to the reflected signal is compared. Doppler-Shift will alter the frequency of the returned signal, which will increase if the target is heading towards the source or decrease if heading away from it. The amount of change can be measured and the speed of the target accurately calculated.
The three ways of avoiding active systems are absorption, deflection or disruption. The signal from the source is absorbed by the skin of the target, deflected so the reflected signal does not return to the signal source or disrupted by a not too dissimilar signal so that the receiver can’t interpret the reflection. A combination of all three is obviously optimal.
The US military has spent hundreds of billions of dollars to develop aircraft and ships that can foil various tracking systems. Each individual craft costs billions to manufacture and maintain using the latest in ceramic, carbon-fibre, Kevlar and alloy compounds, not to mention the state-of-the-art electronic warfare packages employed to confuse the complex and intelligent radar tracking systems that are used by the worlds armed forces today.
And Suzuki has employed this technology to make the world’s first stealth-motorcycle! STEALTH MY ARSE!
[This message has been edited by Tangram (edited 02 August 2000).]