The Doppler effect caused by the dynamic rotation of the wind turbine blades is an important evidence for the identification of the wind farm clutter from the nearby radar stations.It is the difficult to obtain accurate radar echo signal of wind turbine blade by the existing methods

thus the accurate Doppler spectrum cannot be obtained.Consequently

the problem of accurate simulation of radar echo for wind turbine blades is avoided

and a new idea is proposed to solve the Doppler spectrum by using the dynamic RCS of the blade through the study of the mechanism of the Doppler effect.Based on the matured dynamic RCS exact solution techniques of electrically large size targets

the time domain RCS curve of blades in dynamic motion state is obtained with the quasi static method

using the hybrid algorithm of physical optics method（PO） and of equivalent currentsmethod（ECM）.Based on this method

calculation and analysis of the wind turbine blades Doppler characteristics in the rotation

torque

waving and tilt conditions provide a reference for the recognition for radar target signal of wind turbine

the reduction of radar cross section（RCS）

and wind farm clutter suppression of the nearby radars.