Research On The Micro-physical Characteristics And Classification Of Precipitation Based On The PMCS

The micro-physical properties of the precipitation play key role in the inversion of precipitation by radar,the microwave attention by precipitation,and the development of numerical weather prediction.At the present stage,the common domestic disdrometers could not measure the shape and velocity of the hydrometers,and are limited in the study of drop size distribution.Some foreign disdrometers have the capacity to measure the shape and velocity of precipitation,while deviation remains caused by the limited measurement principle.The Precipitation micro-physical characteristics sensor(PMCS for short)developed by our institute have the capacity to the simultaneous measurement of the size,shape,fall velocity of precipitation particles,which can be used for the study of the micro-physical characteristics of hydrometers.In this paper,a calibration and test system for the PMCS is developed,by which the performance of PMCS is evaluated using the model hydrometers;The synchronous observation of a PMCS,an OTT PARSIVEL disdrometer and a rain gauge is conducted,by which the rainfall intensity,accumulated rainfalls,size distribution and spectral parameters are compared each other;The raindrop outline is obtained using the Lagrange interpolation method,and the axis ratio,velocity,and canting angel of raindrops and snow were obtained from the measured data during 2015-2016 in Nanjing area;Finally,based on the geometry,gray and velocity information obtained from the particle images,the precipitation particles classified model is built with the support vector machines method.The above results are conductive to understand the micro-physical information of hydrometers,and promote the application of the micro-physical information obtained by PMCS.