Fine air turbulence characterization by airborne weather radar

Airborne weather radars have a specific Doppler mode for atmospheric turbulences avoidance. Indeed, turbulent areas may be encountered where classical reflectivity measurements do not indicate special hazards. Usually, the severity of turbulences is assessed from the measurement of the radial velocity variance of the wind field ahead, assuming that the turbulence has isotropic statistical properties. However, this measurement is not sufficient because the effect, in term of g-load on the aircraft, also depends on the spatial autocorrelation function of the wind field. This paper deals with an accurate method of turbulences assessment, even with low SNR, because the available power for such radars is limited.