Research ongoing into avoiding aircraft icing
WASHINGTON. Researchers at the U.S. Naval Research Laboratory (NRL) believe that they are close to cracking the code regarding how to provide aircraft with a way to avoid potentially hazardous icing conditions.
The accumulation of ice on airborne aircraft is the result of a weather phenomenon called "supercooled liquid clouds," which -- says Ian Adams, an electrical engineer in NRL's Remote Sensing Division -- can cause aircraft to ice over quickly because the liquid water droplets are below the freezing point and will freeze after contact with the surfaces on an aircraft. Adams says that supercooled liquid clouds are difficult to detect using conventional ground-based or airborne weather radars, as such instruments lack information on the temperature of clouds and precipitation, and supercooled droplets are often too small to be detected by radar.
The NRL team is investigating the feasibility of a forward-looking passive millimeter-wave radiometer as a sensor. Using a computer-simulated instrument response of a forward-looking sensor, simulations showed promise: “So far, the model shows a strong signal at two distances when compared with a clear-sky scenario,” Adams said. “It shows supercooled liquid layers not visible to ground-based radar.” Additional simulation work will expand the set of atmospheric conditions modeled. The research team is also collaborating with other divisions within the NRL to investigate the possibility of using graphene in the detector to reduce size, weight, and power to make a sensor useful with small unmanned aerial vehicles (UAVs).