The Research On Two Channels' I/Q Data Processing Methods Based On Dual-polarization Doppler Weather Radar

Dual-polarization Doppler weather radar is based on the simultaneous transmission and simultaneous receiving of horizontal and vertical polarization wavelength technology which can provide two channels scatter echo from meteorological targets.Three basic parameters?intensity,velocity,spectrum width?of Doppler radar and each polarimetric parameter can be detected by two channels echo signal.In this paper,the echo polarimetric parameter processing algorithm and two channels echo contrast are studied based on the two channels I/Q signal.Then the polarimetric parameters of two kinds of transmit-receive system are compared by simulating alternate transmit-receive mode data.Firstly,the estimation method of echo polarimetric parameters?reflectivity,differential reflectivity,differential propagation phase constant,correlation coefficient?and the comparison of their processing effects are carried out based on two channels'I/Q data.The results show that the whole processing effect of the polarmetric parameter is good,and the correlation coefficient data has the minimum deviation.The polarimetric parameter is very unstable and the data quality is poor with low SNR or weak echo.Then,the echo intensity,velocity,spectrum width of horizontal and vertical channels are obtained by using two channels I/Q signal,and comparative study of two channels echo parameters is carried out.The comparison results show that the two channels'echo is basically the same,the intensity data existed some difference at different intensity,and the difference of velocity data is small.Finally,the echo data of the alternating transmit-receive mode are simulated by interval sampling,and the polarimetric parameters of the two trans mit-receive modes are studied.The results show that the difference of the reflectance factor Z and differential propagation phase constant K_DP is smaller,the quality of differential reflectivity Z_DR is poor and the correlation coefficient is obviously smaller in the alternating transmit-receive mode.