News Release

NCAR scientists win award for in-flight turbulence prediction

Grant and Award Announcement

National Center for Atmospheric Research/University Corporation for Atmospheric Research

BOULDER--A warning system to help pilots navigate storms without encountering air turbulence has earned a NASA award for its design team at the National Center for Atmospheric Research (NCAR). NASA will present the NCAR team and other NASA team members with a Turning Goals Into Reality award on June 11.

"The purpose was to create something industry could put on aircraft and help prevent accidents," says Larry Cornman, one of two leaders on the project from NCAR. "This new technology shows that it is possible for airborne radars to be used to give pilots warnings of at least 30 seconds in advance of turbulence."

NASA sponsored the research. NCAR's primary sponsor is the National Science Foundation.

The project started several years ago with the goal of upgrading radars on commercial aircraft to provide useful turbulence information. Specifically, the NCAR team wanted to determine which regions of low radar reflectivity are safe from turbulence.

Reflectivity refers to the amount of radar signal bounced back by raindrops, ice crystals, and snow. Pilots use reflectivity readings from on-board radars to maneuver around storms. A pilot may assume a region of low reflectivity is safe and fly through it only to experience turbulence in this dryer area.

The team tackled the problem in two steps. First the scientists ran computer models that simulated clouds and turbulence. Then they simulated radar returns within the clouds. The radar simulations helped them develop the NCAR Efficient Spectral Processing Algorithm (NESPA), a quality-control and turbulence prediction formula for use with airborne Doppler radars like those on commercial airlines. NESPA will help pilots decide which low-reflectivity regions are safe to fly through.

In a test flight last summer, scientists used NESPA on the NASA B-757 aircraft as it flew through numerous thunderstorms. The plane encountered 42 cases of moderate or greater turbulence. NESPA had an 80% detection rate and made very few false predictions, even in areas where the radar return was very low.

Now that the team has demonstrated NESPA's feasibility, the next step will be refining and evaluating the results, as well as setting standards to certify industry products for detecting turbulence that are developed from NESPA.

Robert Sharman led the project along with Cornman. Other staff who worked on the project include Shelly Gerding, Greg Meymaris, John Williams, Beth Chorbajian, Rod Frehlich, Todd Lane, and Teddie Keller, all from NCAR's Research Applications Program.

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