Convection Based On Census Peak Method And Fuzzy Logic Method Cloud Area Identification

Historically,meteorological disasters have seriously threatened people's personal and property safety,and convective cloud precipitation is the most important cause of meteorological disasters.Therefore,it is of great significance to effectively identify convective cloud regions and stratified cloud regions.Firstly,this article summarizes the characteristics of echoes of different types of precipitation clouds and radar-based products such as reflectivity factors detected by radars and radar-derived high radar output products.Precipitation cloud types can be roughly divided into convective cloud precipitation,stratiform cloud precipitation,and mixed cloud precipitation.Among them,the convective cloud precipitation echo usually presents an irregular massive distribution,and the echo intensity value is large;the layered cloud precipitation echo usually presents a flocculent or continuous sheet,with a small vertical thickness,etc.;while the mixed cloud precipitation It is a mixture of convective cloud precipitation and stratiform cloud precipitation.It is often seen that structurally uniform layered clouds contain many structurally convective convective cloud monomers.Radar basic products are basic data such as reflectivity factor,average radial velocity,and velocity spectrum width obtained by direct detection of precipitation clouds by Doppler weather radar,and are presented through different coordinates,with features such as obvious characteristics and strong real-time characteristics.Radar products are data and images obtained by processing and processing radar basic products.Secondly,this paper compares and analyzes some common convective cloud region recognition algorithms—the peak value method,the fuzzy logic method and the wavelet transform method.The peak-peak method only considers the two-dimensional morphological features of the precipitation cloud,and it is easy to misjudge the precipitation cloud region,and the recognition range of the layered cloud region is too small;the fuzzy logic method needs very rich experience in recognizing the precipitation cloud region and requires testing a large amount The data samples are difficult to achieve in reality.The wavelet transform method is sensitive to the selection of parameters such as template size,which will have a certain impact on the recognition results,and the time complexity of the algorithm will increase with the increase of the number of wavelet decomposition layers..Finally,aiming at the deficiencies of the above-mentioned single identification method,this paper proposes an improvement,that is,first selects six candidate recognition parameters based on the three-dimensional morphology features of convective cloud and stratiform cloud,and then uses the peak-to-peak method to perform weather radar data for precipitation cloud regions.The preliminary division can not only reduce the error caused by human experience in recognizing the precipitation cloud region in the fuzzy logic method,but also increase the recognition reliability of the precipitation cloud region;then it passes the preliminary selected convective cloud region and stratified cloud region pair.The candidate recognition parameters are combined with the probability density algorithm to perform probability density feature statistics,and three identification parameters are obtained as the input parameters of the fuzzy logic method.Then the fuzzy logic method is used to calculate the precipitation cloud region,and the vertical maximum reflectance is used as a reference.The recognition result analysis verifies the effectiveness of the improved algorithm.