An update on the FAA Aviation Weather Research Program’s in situ turbulence measurement and reporting system

In the early 1990’s work was begun at the National Center for Atmospheric Research to develop and deploy an in situ turbulence measurement and reporting system for commercial aircraft. Two principal algorithms were developed to measure the eddy dissipation rate (EDR) from on-board data. The first method uses vertical accelerations and a mathematical model of the aircraft response to turbulence in order to estimate EDR values, whereas the second method uses a calculation of the vertical wind component. The accelerometer-based algorithm has been deployed on approximately 200 United Airlines B-737 and B757, whereas the wind-based algorithm will be deployed on aircraft from other commercial carriers over the next few years. In this paper, a description of the algorithms is presented along with the results of different verification activities, including intercomparison with pilot reports, flight test data and simulation.