A Little Radar May Make the Future Look Less Alarming

If you've ever had a hard time parallel parking....

If you've ever had to deal with your car's blind spots....

If you've ever wanted a cheaper way to protect your home from break-ins....

Then a little radar may be in your future.

Using military technology, a scientist has found a way to shrink a sophisticated $40,000 radar system into a $10 gizmo not much bigger than a deck of playing cards. The result is something even he was unprepared for.

"I thought: 'Man, this is going to be the world's greatest burglar alarm," recalls Tom McEwan, the radar's inventor and a former electronics engineer at Lawrence Livermore National Laboratory in Livermore, Calif. In fact, more than 200 companies have visited him in the past two years with ideas for everything from toys to automatic-door openers, mine detectors to robotic golf caddies.

One of the first companies to work with the technology is Amerigon Inc., a Monrovia, Calif., concern that is working with several automakers to create car radars. The first devices are likely to be used to alert drivers to objects when they're backing up. They could also help eliminate blind spots in a car. "I really think in the future, every car is going to have this bubble around it," Mr. McEwan says.

Work is also continuing with what he calls the "stealth" burglar alarm. Most alarm systems need a clear line of sight to protect something. Because this radar goes through walls (but not metal or people), a company is working with McEwan to market within a year cheap home-security radars that could be hidden in a cookie jar. If an intruder crossed the radar's path, the device could automatically and silently alert police.

The first applications of the technology have been more industrial than consumer-oriented. Measuring the fluid in tanks is one example. Because today's sensors can be tricked by excess vapor and other problems, they can't always reliably tell operators how much fluid is in a tanker, which can cause overfilling.

So a Canadian company has licensed McEwan's "micropower impulse radar" to build a device that replaces its mechanical float sensors for about one-third the price. Remote Data Systems, based in Whiteville, N.C., has developed a similar device for environmental monitoring of water levels in ponds and streams. The new radars are a big improvement over the company's earlier electronic devices, which could be fooled by heavy fog, rain, or foam on the water surface, says Bill Applewhite, Remote Data's operations manager.

To understand how it works, imagine yelling at a canyon wall, then covering your ears until the specific time you thought the echo would come back. If you heard something, you could figure out exactly how far away the canyon wall was. The radar works on the same principle, except that its pulses travel at the speed of light rather than the speed of sound. And instead of sending out one signal, it can send out some 2 million a second, which allows it to figure out if anything's out there within a few inches to many feet. It's this barrage of signals that allows the radar to create a protective bubble that can send out an alert if anything comes within its path.

Creating exactly the right size bubble is not always easy, as the engineers at Amerigon are finding out. To create a detector for drivers backing up a car, for example, they've had to go to great lengths to make sure the radar bubble isn't too wide (where it would send false alerts from, say, a stray branch) or too low (where it could interpret a manhole cover as an obstacle).

Still, development continues and consumers could see the first security alarms and mini-radars for cars by the end of this year.

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