Magazine article National Defense

Civilian Drones Have Yet to Pass Weather Test

Magazine article National Defense

Civilian Drones Have Yet to Pass Weather Test

Article excerpt

Researchers at the Army's White Sands Missile Range in Arizona are developing weather forecasting software to help unmanned aerial vehicles fly in a variety of climates.

Their research would provide important data to government and industry developers of UAVs intended to be flown in U.S. national airspace.

While the use of UAVs as surveillance tools has grown significantly in the military, the domestic market has been slow to take off, mostly as a result of safety concerns and technological shortcomings. Among those concerns is whether UAVs are capable of operating in all weather conditions, researchers said.

Sudden wind changes, icing of camera lenses and restricted flight corridors can interfere with the operation of smaller UAVs, said team leader Terry Jameson.

"If the optical instrument gets condensation on the lens [and] freezes, you can't see," he said.

The Federal Aviation Administration so far has severely restricted the use of commercial unmanned aircraft in domestic airspace. But there is a growing list of government programs that are seeking increased use of the technology.

Adm. Thad Allen, commandant of the Coast Guard, recently announced that the service will team with Customs and Border Protection to fly mid-altitude Predator UAVs over the Caribbean and Pacific Ocean. In addition, CBP has begun flying the drones along the northern border.

The National Oceanic and Atmospheric Administration has invested $3 million in a pilot program to use UAVs to monitor hurricanes in the Gulf of Mexico and Atlantic Ocean. Flights to the Arctic and Pacific Oceans are also scheduled for spring 2009, according to NOAA.

NASA has also received a prototype Predator and a Global Hawk--a high-altitude military UAV--to survey forest fires.

Predators and smaller sized UAVs have mostly been used in drier, desert-like conditions in Iraq and along the southern U.S. border. These new applications will test their ability to fly in more volatile atmospheric conditions, White Sands researchers said.

These researchers work primarily with smaller UAVs. Global Hawk is an unlikely candidate for domestic missions. Smaller, lighter planes such as the Aerostar and Predator would fly between 15,000 and 30,000 feet and survey hurricane formations in the Gulf and Atlantic or patrol borders and fisheries.


The smaller the UAVs, the more they are affected by local wind patterns and other weather-related factors, said David Knapp, chief of the atmospheric modeling applications branch at the range.

Navigation systems are also a concern, said David Rockwell, co-author of a Teal Group industry forecast. UAVs generally have only electrooptical sensors--cameras that detect movement on the ground such as illegal immigrants or drug smugglers entering the United States.

"Electro-optical doesn't see through weather any better than human eyeballs," he said.

UAVs built for military use often are equipped with synthetic aperture radar (SAR), which can see through cloud formations and weather. Doppler radar is one type of SAR, which civilian UAVs do not have, Rockwell said. The FAA also requires that all commercial airplanes have sense-and-avoid technology to prevent collisions. If UAVs share the airspace with passenger planes, they too will need mechanisms to avoid crashes, said Jameson.

"Sense-and-avoid is critical, but it's a real struggle to find the technology to do so," he said. …

Search by... Author
Show... All Results Primary Sources Peer-reviewed


An unknown error has occurred. Please click the button below to reload the page. If the problem persists, please try again in a little while.