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Keeping an Eye on the Sky
Radiometrics radiometers Radiometrics Corporation’s radiometers are powerful tools for short-term weather forecasting.
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modular polarized radiometers The company’s modular polarized radiometers—developed from its NASA partnership—are used in soil, snow, ocean, and atmospheric research.
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A NASA spinoff helps monitor dangerous conditions for aircraft—and keeps track of the weather for sporting events.

One of the greatest dangers to aircraft—playing a role in numerous destructive and fatal accidents around the world—comes in the form of droplets of water.

Clouds are made up of tiny water particles. In clean air, cloud droplets can exist in liquid form down to temperatures as low as -40 °C. These subfreezing, liquid clouds are referred to as being “supercooled.” As soon as supercooled droplets contact an aircraft ascending or descending through the cloud cover, they form layers of ice on any unprotected surface. This can lead to reduced performance and even catastrophic loss of control.

As part of its aeronautics research, NASA has extensively investigated the icing problem, leading to numerous spinoff technologies that are helping reduce the threat. Glenn Research Center has led the Agency’s efforts, testing thermal, chemical, and mechanical anti-icing technologies in its Icing Research Tunnel; developing software tools for modeling ice growth and the impact of icing on aircraft performance; and producing pilot training aids for flight in icing conditions.

“Seeing Things in Nature That Have Never Been Seen Before”

One way of combating the dangers of ice buildup is through the accurate, real-time identification of icing conditions, and researchers at Glenn have studied ways to detect supercooled water droplets in the flight paths of aircraft in and out of airports. One such method involves combining weather radars with devices called microwave radiometers, which measure the energy of liquid water and water vapor in the atmosphere. The combined technologies can provide essential information for determining icing risk.

Radiometrics Corporation, of Boulder, Colorado, partnered with NASA to advance microwave radiometer technology for the detection of icing conditions. The resulting technology, is “a pioneering instrument that is seeing things in nature that have never been seen before,” says Randolph Ware, vice president of sales and marketing for Radiometrics. “You can locate this instrument in an airport, look at a narrow beam width along a flight path, and detect the supercooled liquid that creates the icing hazard.”

From the Airport to the Olympics

While a commercial version of the NASA radiometer is still in the works, Radiometrics has brought to market a modular radiometer, originally developed as part of the NASA partnership. The devices are powerful tools for improving local, short-term weather forecasting and producing high-accuracy nowcasting (the forecasting of weather within a 6-hour timeframe).


In keeping with the typical cycle of successful technology transfer, NASA is also benefiting from Radiometrics’ commercialized technology. NASA’s Jet Propulsion Laboratory has purchased modular radiometers for its Deep Space Network, a worldwide antenna network supporting solar system exploration.
