Is it better to assimilate the Doppler radar radial velocity directly than retrieved winds with Ensemble Kalman Filter?

The comparison of two methods of assimilating Doppler radar wind data with Ensemble Kalman Filter (EnKF) based WRF model is presented. One is to assimilate simulated radar radial velocity observations directly. The other is to assimilate the horizontal winds retrieved from Doppler radar Data. Result shows that the second method which assimilated retrieved winds with small retrieval error gives better analysis than the first method does.