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Radar for your car?

Radar will likely beat out laser, sonar, and camera technology when it comes to obstacle detection in cars, analyst reports.

Greater availability of silicon germanium chips and better reliability in bad weather will make radar technology favored over other automotive obstacle detection technologies, according to an ABI Research report released Wednesday.

There are four major types of obstacle detection technologies currently used in vehicles for applications like blind spot detection and parking assistance. Radar will probably win out over sonar, lidar, and cameras, said David Alexander, principle analyst at ABI Research, who specializes in telematics and automotive research .

"Lidar and radar were a couple years ago on a few cars and they were the competing systems...There are lidar systems for about $600 and the radar systems tend to be about $2,000. We thought there would be a boost for lidar, but over last couple of years this hasn't happened. We see that radar sensors are going to come down in cost significantly and it is also much more reliable in bad weather conditions," said Alexander.

Radar uses radio waves that bounce off obstacles. There is a transmitter and antenna that receives the signal. Radar can determine not only the obstacle, but also its speed in relation to the vehicle.

"A radar beam does not care if an object is reflective. If it's a solid object (radar) will detect (it)," said Alexander.

Lidar, on the other hand, uses a low-power laser to emit a beam and analyze its reflection to determine the speed and proximity of a nearby object. But because it uses a form of light that is easily reflected, dispersed, and sometimes absorbed, lidar does not do as well as radar in snow, fog, and heavy rain--when drivers likely need their blind spot detection most. Lidar is also less reliable than radar when faced with a nonreflective object like a car with caked-on mud.

The sensors used in radar systems will also soon be coming down in price. That will make the pricey but more reliable technology even more viable, said Alexander.

Radar sensors are currently expensive because they use gallium arsenide, a combination of elements for its sensor core that are very expensive and difficult to get manufacturers to work with it. It is commonly found in military and aviation radar uses. But the other technology that can be used is SiGe (silicon germanium).

"They're expecting SiGe chips to be available in 2009 and in volume in 2010. What's nice with these SiGe (chips) is that manufacturers have experience manufacturing these types of things quickly, accurately, and cheaply, and so expect the price to come down as volume grows, " said Alexander.

Cameras with image analyzing processors will also have their place.

Several manufactures have been using one or more cameras coupled with analyzing image processors. These cameras have multiple functions in obstacle detection, whereas with radar and lidar there is only the ability to detect an object and its speed. Even though the systems are expensive and not as reliable as people would like just yet, cameras can detect things like road markings and, therefore, be used for lane-departure warning systems. That's something radar and lidar simply can't do.

The newest generation of adaptive cruise control also uses a combination of cameras and sensors, allowing it to work better in stop-and-go cruise control modes.