Mobile Micro Rain Radar


When an ice storm hit the Triangle area in December 2002, thousands of homes lost power. Worse, utility trucks were slowed in their efforts to restore power because many were located outside the affected area and could not travel on ice-covered roads. A better ability to predict ice storms could have put the trucks where they were most needed before the ice hit and resulted in a quicker restoration of essential services.

RENCI has deployed a Mobile Micro Rain Radar (M²R²)—one of only six in the U.S—to improve ice storm prediction. The radar detects precipitation in the atmosphere and how high above the ground that precipitation will freeze—the freezing line. Above the freezing line, precipitation is frozen, and how close to the surface that line is determines whether precipitation falls as rain, freezing rain, sleet or snow.

M²R² is mobile enough to move as conditions demand, but will likely spend much time in the western Piedmont area, the part of North Carolina most frequently hit by ice storms. It gives the National Weather Service and other users a needed data point in that area and helps in determining where and when ice is likely to hit. The radar data is collected by an on-site computer and transferred via a cell phone network to a RENCI server and then displayed on a website. The system updates in minutes and can be accessed from the Web by forecasters, planners, utility companies, rescue workers and government officials.

The radar also can be used to accurately predict rain rates. RENCI is working with Ana Barros, a professor in the civil and environmental engineering department at Duke University, to learn more about the rainfall patterns and amounts in the Southern Appalachians of North Carolina. The radar data from the field experiment will measure rainfall levels and how rainfall varies in size, velocity, and intensity depending on the elevation. It will also help researchers understand how rainfall changes from the point where it is produced in the clouds to where it hits the land surface.

M²R² Details

  • 24.1 GHz. Outputs 50 miliwatts of power.
  • System consists of a 2-foot antenna dish, radar, receiver unit, and an RS-232 data transmission interface.
  • System is mounted on a trailer for transport so it can easily be moved based on approaching weather conditions.
  • Measures drop size distribution
  • Derives fall velocity and reflectivity.
  • Data is transmitted to RENCI in real time and posted for download.


  • State of North Carolina
  • Duke Energy

Project Team

  • Jessica Proud, project leader
  • Erik Scott
  • Dan Bedard
  • Jim Mahaney
  • Mats Rynge


  • National Weather Service
  • Ana Barros, Duke University Pratt School of Engineering
  • Guilford County Emergency Services
  • Institute for the Environment