Research On High Stability Optical Rain Gauge

Precipitation observations are becoming more and more important for disaster warning and agricultural development.Rain gauges play a positive role as the most direct means of rainfall measurement.The most used mechanical rain gauge has inherent shortcomings.With the development of photoelectric sensing technology,the combination of rain gauge and photoelectric technology can overcome the shortcomings of mechanical rain gauges and it can bring the advantages of real-time monitoring and transmission,however,the optical rain gauge is still in its infancy,and the related technology needs to be improved.Aiming at the shortcomings of low stability of optical rain gauges,this paper proposes a method to improve the stability of rain gauges based on light scattering technology.This article first compares the existing optical detection technology and studies the theoretical part of the optical detection technology,including theoretical analysis of scattering,design of scattering model,research of Fresnel lens principle and overall design plan;design of rainfall detection system devices and select system components and study the characteristics of the device,as a theoretical basis for the subsequent experimental design;specifically analyze the factors affecting the stability of the system hardware,and derive the scattering formula,simulate the relationship between the scattering angle,wavelength and the scattering effect,and obtain Three representative scattering angles of 45°,90° and 135° are set out,and the three angles are used as the receiving angles of the subsequent experimental detectors.In terms of hardware,by selecting appropriate integrated devices,improving the stability of the light source and reducing the noise impact of the detector,it is used to improve the quality of incident light and the receiving efficiency of the detector;the wavelength and scattering angle are experimentally verified,and different results are obtained.Wavelength data and three-angle scattering signal data.Finally,45° data is selected as the training data of the algorithm.The 45° scattering signal data is divided into training set and test set in a 2:1ratio,and SVM algorithm training is performed on the training data.,Get the trained algorithm model,and further compare the predicted value,the direct measurement value and the real value.The error between the predicted value and the real value is [-0.3m L,0.4m L],and the error percentage fluctuates between [-1.5%,1.7%],and the error between the direct measurement data and the true value is [-1.3m L,2.6m L],and the error percentage fluctuates between [-3%,3%].It can be seen that the SVM prediction model can improve the stability of the data.Research shows that the light source,circuit noise,and scattering effects in the detection system all have different effects on the stability of the system.The research and correction of the above factors have improved the stability of the system,especially the introduction of algorithm models,which can improve the stability of the data.