Study On Optimal Processing Of X-band Dual-polarization Doppler Weather Radar Echo Data

X-band dual-polarization Doppler weather radar has the advantages of small size,low construction cost and high sensitivity,and is widely used in fine detection of small and medium scale weather.Compared with ordinary Doppler weather radar,dual-polarization radar has a very obvious advantage in the quantitative estimation of precipitation.However,due to the short wavelength of X-band dual-polarization weather radar,its corresponding attenuation coefficient will be larger,and radar echo data will be more easily covered by noise and clutter,thus causing serious pollution to weather echo data.It is difficult for users to extract effective weather information from echo data for analysis,which will eventually affect the business application of radar.Based on this,it is necessary to conduct quality control on radar base data,identify and remove noise data and clutter data as much as possible,and reduce the interference caused by meteorological echo information.Taking the improvement of radar data quality as the starting point,this paper conducts research from two aspects: radar data quality control and echo classification and identification.Firstly,an adaptive filter based on LMS algorithm is studied and constructed,and the adaptive filter with good performance is finally debugged after the coordinated adjustment of out-of-sync length and iteration times.The echo intensity,radial velocity and velocity spectral width are selected as input data to verify the filter effect.The results show that the convergence effect of the filter performance curve is good,and the processed radar base data fits well with the expected data,which lays a foundation for the further application of radar base data.Secondly,the fuzzy logic algorithm is constructed to realize the classification and recognition of weather radar echoes.Four characteristic parameters,namely,the standard deviation of reflectance,the vertical gradient of reflectance factor,the mean value of radial velocity region and the mean value of velocity spectrum width region,are selected as the characteristic parameters of weather radar echo recognition,and the probability statistical analysis of the characteristic parameters is carried out to determine the membership function of each characteristic parameter,and in the process of determining the weight of characteristic parameters,The entropy weight method is used to optimize the weight coefficients,and better weights are provided for each characteristic parameter,so as to achieve better echo recognition effect.Finally,an example is selected to verify the effect of radar echo classification recognition.The results show that the algorithm can accurately identify non-meteorological echoes and eliminate them,and fill the echo holes caused by the elimination.The data quality control of X band dual polarization Doppler weather radar is realized and a better data quality control scheme is provided for the operational application of the X band dual polarization Doppler weather radar data.