Research On Detecting And Distinguishing Precipitation Particle Based On Technology Of Laser Shadowgraph

precipitation is commonly defined as a sort of weather phenomenon,that the solid, liquid or mixed hydrogel (frozen) particle in the cloud fall to ground. Correctly detecting the physical characteristic of precipitation particle and and reporting precipitation type is significant to weathe forecast, climate analyse, military security, roduction of industry and agriculture and people’s daily life. At present, developed countries have basically realized the automatic observation of precipitation phenomenon, however, it is mainly in manual observation in China.Therefore,the research on the theory, method and technology of detecting precipitation particle based on shadow laser is practically value to developing precipitation phenomenon sensor independently and accelerating the realization of automatic weather observation.Bsed on contrast with and analyzing present precipitation monitor technology,this paper put forward a system that uses the technology of lase shadow to measure dimension and velocity of precipitation particle and uses ARM to manage and process signal,study the theory,key technology and built a experiment system.The test of particles in different characters indicates that:this technology is feasible,the system can measure dimension and velocity in line.,thereby, it can distinguish the type of particle.This paper has completed the following work:1. Theory of technology of Laser Shadowgraph was studied.Has built a system model of detecting dimension and velocity of precipitation particle preliminarily and analyzed the main error of the section of optical sensing.2. Has designed and built an experiment system of detecting dimension and velocity of precipitation particle based on the technology of Laser Shadowgraph sensing and ARM.The hardware section includes Optical sensors, analog signal processing,data collection and Control module based on ARM. Software section includes data collection and storage.data analysis and processing. Data Transmission and Display,calculating dimension and velocity of particle and so on.3. Have designed a installation simulating installation particle and done the experimental calibration of precipitation dimension and velocity of particle in use of the installation.At last,this paper put forward digital filtering algorithms to romove the interference from the datas4. Have done an experiment test in use of some particles different size and speed characteristics.