Gradient VAD Technology Based on Extended Kalman Filter Algorithm
Gradient VAD technology is proposed to overcome the significant impact of velocity ambiguity on traditional VAD techniques.How-ever,during the use of gradient VAD technology,errors or noise in radial velocity can be amplified in the radial velocity azimuth gradient.Therefore,low-pass filtering is usually used to smooth the radial velocity azimuth gradient.However,it still has a serious impact on the accu-racy of horizontal wind inversion.This article proposes to use the extended Kalman filter(EKF)algorithm to process the radial velocity gradi-ent in the azimuth direction.The results show that theextended Kalman filter algorithm can effectively reduce the influence of small fluctua-tions and noise in the radial velocity gradient in the azimuth direction,thereby improving the horizontal accuracy of wind field inversion.In this article,the Xiamen SA band Doppler radar data was preprocessed twice with velocity un deblurring and velocity de deblurring,and then compared with low-pass filtering and EKF.The results showed that the variance of EKF algorithm compared with low-pass filtering algorithm was reduced by about 40%and 50%respectively in the process of velocity de deblurring and non thrust blur data processing.This indicates that the radial velocity gradient after EKF processing is more stable,thus improving the inversion accuracy of gradient VAD technology.
extended Kalman filter algorithmgradient VADDoppler weather radarwind field inversionlow-pass filtering
国家科技期刊平台
NSTL
万方数据
