Radar data has high temporal and spatial resolutions compare with other instrument which can measure local air motion like wind profiler, radio sonde end so on. Most of dynamical functions and indexes are calculated from wind vector. However, radar only measure wind component of beam direction. So various methods have been suggested for the retrieval of the wind vector field from radial velocity data. For example, Velocity Azimuth Display((VAD, Browning and Wexler, 1968), Double-VAD(DVAD, Scialom and Testud, 1986), Volume Velocity Processing(VVP, Waldteufel and Corbin, 1979), dual-doppler wind analyses(Shapiro and Mewes,1999), a variational multiple Doppler radar three dimensional wind synthesis method(LC09, Liou and Chang, 2009) and so on.
In this study, retrieval three-dimensional wind field by LC09 with stimulated reflectivity and radial velocity data. Radar data is stimulated from weather research and forecasting(WRF) model with 9 operation radar in KOREA.
Experiments using model-simulated radar data are conducted at four case. First case is stratiform rain case. second case is typhoon case which has strong rotational wind. third case has rain front, fourth case is thphoon case which has strong wind.
Accuracy analysis is composed two compare processes. First process compare between WRF model wind vector and retrieved wind vector by LC09. This comparing indicate accuracy both of stimulated radial velocity and LC09(compare1). Second process compare between stimulated radar radial velocity from WRF model data and retrieved radial velocity by LC09. This comparing only indicate wind retrieval accuracy of LC09(compare2). Accuracy analysis is composed by root mean square error(rmse), relative rmse(rrmse) and correlation coefficient(Corr).
Compare1 have 4.472 rmse and 0.1859 rrmse. compare2 have 1.579 rmse and 0.089 rrmse. This result indicates LC09 can retrieve 3D wind fields which are good matched with observed radial wind. And error diffreence between compare1 and compare2 indicate that radar have 2.893 rmse and 0.0969 rrmse cause of pulse volume problem.
Analysis of each layer indicate that middle layer(2.5~8.5) is best area to retrieve 3D wind fields by LC09. And spatial distribution of wind speed rmse indicate that the area where has many observable radar has low rmse and rrmse, and the area where far from radar has high rmse and rrmse.