Design Of Rain Gauge Based On Video Analysis

Precipitation is a common weather phenomenon.Precipitation events are closely related to people's production and life.At present,most people still use mechanical rain gauges to monitor precipitation.However,mechanical rain gauges generally have the problems of large volume,complex mechanical structure and difficult installation.In view of this situation,this paper designs a rain gauge with small volume,simple mechanical structure and higher real-time monitoring.Using the method of image acquisition,precipitation is obtained by analyzing precipitation images.In this paper,the overall structure and main control circuit board of rain gauge based on video analysis are designed to prevent rain particles from contacting with main components and causing corrosion damage.The main control circuit board comprises a core control circuit,an environment detection module,an image acquisition module and a wireless communication module.The system detects precipitation particles and environmental visibility,controls the work of the image acquisition module,and finally sends the data to the upper computer for display by the wireless communication module.The main control chip selects STM32F429 based on ARM core,and temporarily stores the image collected by the camera in SDRAM through DMA transmission.The main control chip reads the image data in SDRAM for processing.Firstly,the image is preprocessed,and image filtering,image enhancement and other methods are used to eliminate noise in the image and enhance the contrast between precipitation particles and background.Then the image is binarized and segmented to highlight the outline of precipitation particles.In view of the rain line inclination in the image,Hough transform is used to detect the rain line in the image and obtain the inclination angle of the rain line,and the image is rotated to correct the rain line so as to make it vertically downward.Finally,the diameter,number and speed of precipitation particles in the digital image are obtained by connected domain detection and difference method,and the real physical characteristics of precipitation particles are obtained by using the relationship between the number of pixels in the image and the actual detection area.Then the raindrop spectrum distribution function can be constructed to obtain precipitation and precipitation intensity,and the precipitation type can be judged according to the characteristics of different precipitation particle diameters corresponding to different velocities.Tests show that the rain gauge designed in this paper based on video analysis has good measurement results,can realize real-time monitoring of precipitation,and can accurately judge the intensity and type of precipitation.