Radiation Characteristics Consistency Evaluation of Horizontal and Vertical Channel for Dual Polarization Weather Radar Antenna

The consistency radiation characteristics of horizontal and vertical channels of antenna is critical to dual polarization weather radar system. A good consistency can ensure the horizontal and vertical polarized wave to point the same target, meanwhile, to receive backscatter signal from the same target at horizontal and vertical channel, and then the difference of the echo signal of Zh, Zdr, Ödp and ñhv can reflect the real characteristics of the target. The error from radar antenna radiation characteristics of horizontal and vertical channels will cause the error of the polarization parameters mentioned above, further affect the correct judgment of target characteristics. General speaking, this type of error should be as small as possible, but to evaluate the error, a quantitative assessment method will be necessary. In this paper, the radiation pattern of the main lobe for the antenna was simulated by using Gaussian function to get the correlation coefficient of the pointing error, width error for -3dB, -10dB, -20dB of the main lobe. And then, the multiplication of all the correlation coefficients, which is the total correlation coefficient, was obtained for the antenna main lobe above -20dB to evaluate the antenna radiation characteristics of horizontal and vertical channel consistency, and estimate the antenna quality threshold. By using the method to test the radar antenna for the X-band dual polarization weather radar facility in our institute, it shows that the total correlation coefficient above the main lobe of -20dB is about 0.999.