Tech Sees Fire Where There's Smoke   Wildfires that produce a
lot of smoke are difficult to manage because the source of fire
can be hard to see. From the air, firefighting units typically
use infrared cameras to help spot the hottest and most intense
parts of a fire. But when conditions are far to dusty and
smokey, the infrared technology is not effective.  Researchers
at Fraunhofer Institute for High Frequency Physics and Radar
Techniques in Wachtberg, Germany, have developed a sensor that
can see through the smoke. It works at a much lower frequency
than the infrared sensors, and is less affected by dust
particles. It can also see down through thick foliage to locate
hidden areas of fire.  "Particles of dust and smoke are
practically transparent in the microwave range, but the
radiation is still strong enough for the source of a fire to be
detected," said team leader Nora von Wahl. "From a height of 100
meters, we were able to locate fires measuring five meters by
five meters in low visibility conditions,”