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A concept for a snow-penetrating radar device has been patented by research scientists and engineers at °ÄÃÅÁùºÏ²Ê×ÊÁÏ¿â Davis' Advanced Highway Maintenance and Construction Technology (AHMCT) research center. The radar system is being developed as part of a project aimed at automated operation of snowblowers, allowing them to locate and avoid objects buried within snowbanks.

Standard radar systems do not have enough resolution for useful imaging at a frequency that will penetrate snow. In addition, snowbanks have difficult properties, such as layers of salt and dirt, that make them hard to penetrate with radar, said research engineer Ty Lasky. The patent sets out concepts for combining a narrow beam with a signal frequency that can penetrate up to six feet into the snowbank and provide the driver with an intuitive image of buried objects.

While snowblowers are generally robust machines, buried objects such as rocks and discarded tire chains can cause damage, Lasky said. Snow-penetrating radar could potentially also be used for avalanche rescue.

The researchers are currently working on a prototype device. Future work may use new types of materials that have a negative index of refraction, Lasky said. First demonstrated in 2001 by physicists at °ÄÃÅÁùºÏ²Ê×ÊÁÏ¿â San Diego, materials with a negative index of refraction, sometimes called "left-handed materials," reverse the optical properties of normal materials. Proponents think that left-handed materials could be used to build "perfect lenses" for light, microwaves or radio waves.

The project is directed by Bahram Ravani, professor of mechanical and aeronautical engineering, and Lasky.

The AHMCT research group has previously built a snowplow capable of navigating in blizzard conditions. Other projects developed by the team, which is funded principally by the California Department of Transportation, include automated machines for roadside cleaning, laying and picking up traffic cones, and sealing highway cracks.