Error Analysis Of Differential Reflectivity Factor And The Implementation Of Its Correction Method Based On Calibration-Source

Dual-Polarization Doppler radar will be a developing direction of weather radar, and application of dual-polarization technique can not only provide conventional meteorological products such as radar reflectivity(ZH), speed(V) and spectrum width(W), but also can provide differential reflectivity factor(ZDR), propagation differential phase shift(Phv(0)),specific differential phase shift(KDP)and the correlation coefficient(phv(0)), which are closely related to hydrometeor classification and rainfall measurement, and Dual-Polarization Doppler radar has a wider application than conventional weather radar, therefore, the key technique of the dual-Polarization radar is discussed in this thesis.Based on the C-band Dual-Polarization Doppler radar which made by Anhui Sun-Create Electronics Limited Company,the paper firstly gives introducion about the detection and working principles of the radar. The differential reflectivity factor is the one of the important parameters for the hydrometeor classification and target feature identification If the measurement error does not meet the requirements, it will seriously affect the function of the Dual-polarization detection, and subsequent detection of data processing and information extraction are also lost its practical meaning. Correction of the differential reflectivity plays a vital role in the successful application of polarization radar.In this basis,the reasons for the errors of the differential reflectivity are discussed in details. And then two differential reflectivity correction methods are introduced in this paper. The two methods can be used as detection means for the regular calibration in order to achieve the purpose of the difference reflectivity correction. In the paper, data collection and the field test for both methods are done. The results show that they can correct system error of ZDR well.Finally, a new method which based on calibration source is provided, the method is for the error caused by the receiving channel amplitude and phase inconsistencies.it has the advantage of real time correcting ZDR, and we have the field test in Yunnan, Beijing and other places. Through the data analysis, it shows that this correction method can make the receive channel differential reflectivity precision controlled in0.2dB or less, the results achieve the accuracy requirement for the quantitative estimates of the phase identification and the precipitation. Lay the foundation for the radar to fully play its role in meteorological safeguard field.