NASA researchers are seeking to bring better weather information to pilots and controllers by converting a fleet of regional turboprop airliners for service as flying weather reporting stations.

A team led by NASA’s Langley Research Center in Hampton, Va., has designed, built and equipped dozens of Mesaba Airlines Saab
340s with the so-called Tropospheric Airborne Meteorological Data Report (TAMDAR) instrument, a small weather sensor that automatically collects and reports current weather conditions in flight.

The 1.5-pound TAMDAR sensor unit collects atmospheric conditions and then transmits its data by satellite to a ground collection center. The center processes and distributes up-to-date weather information to forecasters, pilots and weather briefers. NASA researchers believe the experiment will lead to improvements in current weather condition analysis and forecast accuracy.

“Our goal is give pilots better weather information, so they can make better decisions in flight,” said Taumi Daniels, TAMDAR project leader. Installing the TAMDAR units on regional turboprops instead of jets means the data comes from lower altitudes, below 25,000 feet, where most weather is occurring, Daniels added.

The TAMDAR instrument was developed by the Georgia Tech Research Institute in Atlanta and AirDat of Morrisville, N.C., for NASA’s Aviation Safety and Security Program.

The instrument measures humidity, wind speed and direction, pressure, temperature, icing presence and turbulence, compared against location, time and altitude provided by an integrated GPS receiver.

The TAMDAR team has already validated the technology in previous ground and flight tests. The government/industry initiative, called the Great Lakes Fleet Experiment and launched in January, is assessing the performance of the sensor on 64 Mesaba Saab 340s in a real-world operational environment for the first time.

Private industry, meteorologists, researchers and scientists at weather forecast offices are part of the partnership that will analyze the data. The partners include NASA; AirDat; the FAA; the National Oceanic and Atmospheric Administration; the National Center for Atmospheric Research in Boulder, Colo.; Massachusetts Institute of Technology Lincoln Laboratory in Lexington, Mass.; Meteorological Service of Canada in Montreal; the UK MET Office in London; and the Meteorological Network of Europe in Toulouse, France.

Improving Weather Forecasts
All weather forecasts and weather forecasting models could benefit from the data that the TAMDAR team collects, because it increases the number of observations in the lower atmosphere. There are currently only 90 weather balloon sites in the U.S. used to collect temperature, wind and moisture data from twice-daily atmospheric soundings, Daniels said. Integrating Mesaba’s Saab 340 fleet with the Great Lakes Fleet Experiment will add 1,300 more daily atmospheric reports.

The TAMDAR units are installed in Mesaba aircraft operating from hubs in Minneapolis, Detroit and Memphis and flying primarily to small cities throughout the Upper Midwest and South Central U.S. Daniels said researchers hope to determine the value of the airborne observations to aviation forecasters based on the TAMDAR experiment. If researchers deem the trial successful, the units could be added to more regional airliners flying on routes in other parts of the U.S.