基于多普勒天气雷达风场信息的雷达回波外推预报研究

In this paper, Doppler radar radial velocity data and reflectivity factor data are used to conduct radar echo extrapolation. We retrieved the horizontal wind fields at the height of 3km by VAD (velocity azimuth display) method and TREC(tracking radar echo by correlation) method, then used them as the motion vectors of echoes to make the extrapolated forecast in 30 minutes of CAPPI(constant altitude plan position indicating) reflectivity factor at the height of 3km. By comparing the accuracy of extrapolated forecast in different extrapolation times and different precipitations by the two methods in a typical rainfall process in Nanjing, 2010, we have got the conclusion: the results which is forecasted by the VAD method and TREC method coincided well with observation. At the same time we have found that the accuracy of extrapolated forecast tend to decline with the increase of the extrapolation time in these two methods, and the VAD method is more accurate in later period of extrapolation. In addition, the abilities of sounding of these two methods are both more outstanding in low precipitation.