C|net describes the use of radar to find "junk" on runways. The idea is to keep runways clean and reduce damage and loss of life. The technology is from QinetiQ
... Heathrow International Airport, the world's busiest, has now installed a permanent dual radar system called the Tarsier, which scans 3,658 meters of runway in search of junk 24 hours a day.
The Tarsier uses networked high-frequency, high-resolution radar and integrated digital signal processing to pinpoint anything from a pigeon to a cellophane sandwich wrapper (PDF).
Foreign object damage, or "FOD," is responsible for $60 million worth of damage a year, an average of $15,000 per aircraft for each major airline in the U.S. alone, according to the FAA (PDF).
...
The smallest item detected to date is a 10-millimeter metal fitting in an area the size of 30 football fields, the company says. Once an object is found, Tarsier reports its latitude and longitude to within 3 meters via GPS.
