Dual-polarization Doppler Radar Quantitative Detection Of The Method Of Precipitation Intensity

Dual linear polarization radar may provide more radars returning parameters from clouds and precipitation particles than conventional weather radar ,can obviously increase the accuracy of measure estimates improvement radar measurement effect of single point river basin precipitation and precipitation amount increase the radar ability to monitor the forecast . This thesis utilizes the weather process data of three strong precipitation measured on May 10th ,June 12th in 2003,and June 2nd in 2004 by the American KOUN Douplar radar which is reconstructed the dual polarization and one snow falling process data measured by the academy of Beijing meteorology with dual polarization on December 21th in 2004, analyse the method of precipitation of S Band dual polarization and the relations of polarimentric measurands.Firstly ,we proceed to prepare to handle the radar data gotten at the United states KOUN . Because Polarimentric radar cann't measure specific differential phase K_DP directly ,which is fectched from Φ_dp ,we use method of the minimum squares simulation to calculate K_DP, analyse polarimentric measurands'relation, and find some conclusion from polarimentric measurands . In addition, we discovers that the precipitation process is conluded of hailstone on May 10th .We conclude the method of eliminate hailstone echoes from mixing precipitation ,the result insure the dependability of liquid rainfall rate measurements .Then we analyse kinds of methods of rainfall rate measurements' difference for S-band dual linear polarization radar, contrast radar measuring one hour accumulation precipitation with surface data, and discuss the method of the K_dp calculation to influence precipitation .The result indicates that different algorithmic method have more difference, the K_DP calculation is not suitable for the light rain stage.According to the above experiment research, we bring up a kind of method of rainfall measurements: At a precipitation process, according to the difference of reflectivity factor ,we should select the different formula of rainfall measurements to calculate the precipitation by stages.At last ,we have first step analysis for dual linear polarization radar data of the academy of Beijing meteorology, because this precipitation is the process of falling snow with less strength and range, which conflicts with the fluid precipitation analytic previous, so it is just the first analytic step of reliability of polarimentric measurands measured by radar.