Research On Water Vapor Inversion And 3D Chromatography Method Based On GNSS Technology

Although water vapor accounts for only a small part of the troposphere,it is the most active meteorological element and has a significant impact on the atmosphere.It plays an important role in many atmospheric cycles.Small amounts of water vapor changes can cause harsh weather changes such as clouds,rain,snow,sleet and hail.Therefore,accurate detection of water vapor spatiotemporal distribution information is crucial for precipitation and severe weather forecasting,as well as natural disaster warning.However,the temporal and spatial distribution and variation of the atmosphere is very complicated.The observation of atmospheric water vapor distribution and change is one of the important contents and difficulties of atmospheric water vapor research.In the past few years,many techniques have been developed to improve atmospheric water vapor observations,including ground-based observing systems and space satellite remote sensing sensors.Among various platforms,Global Navigation Satellite System(GNSS)is considered to be an effective method to provide atmospheric water vapor data with high spatial and temporal resolution.This paper mainly uses the ground-based GNSS meteorology principle,based on the data observed by the CORS station,discusses the main problems of inversion of atmospheric water vapor information based on ground-based GNSS.The main research contents of this paper are as follows:(1)This article describes the most commonly used tropospheric mapping functions.And when the station lacks meteorological observations,the GPT model established by the empirical model is used.The meteorological observation data downloaded from the IGS station is used as a reference value,and the GPT,GPT2 and GPT2 w models are used to calculate the pressure and temperature of five IGS stations,such as BJFS,HKSL,HKWS(Hong Kong)and TWTF(Taiwan)URUM..The results show that the statistical results show that the accuracy of the air pressure and temperature data calculated by the GPT2 and GPT2 w models are roughly the same.The root mean square error and deviation of the calculation results in the regional IGS stations in China are 7.4 mb and 6.7 mb,respectively,and the results are smaller than the GPT model..For the temperature parameters,the average deviation of the models in 3 is basically the same.(2)This paper introduces the most commonly used static delay correction model,and compares the applicability of the model by statistically distributing the data collected by different longitude IGS stations.It is found that the difference between the two correction models is small.However,the RMS value will show a significantly larger system trend as the latitude increases.The smallest deviation occurs near the equator,the largest being the region with the largest latitude,more than 6 mm.And when the station lacks meteorological observations,the GPT model established by the empirical model is used.The meteorological observation data downloaded from the IGS station is used as a reference value,and the GPT,GPT2 and GPT2 w models are used to calculate the pressure and temperature of five IGS stations,such as BJFS,HKSL,HKWS(Hong Kong)and TWTF(Taiwan)URUM..The results show that the statistical results show that the accuracy of the air pressure and temperature data calculated by the GPT2 and GPT2 w models are roughly the same.The root mean square error and deviation of the calculation results in the regional IGS stations in China are 7.4 mb and 6.7 °C,respectively,and the results are smaller than the GPT model..The temperature parameters,the average deviation of the three models are basically the same.(3)According to the different station observation values provided by the reference station,the annual product days with the same number of observable satellites on the reference station are selected to compare the accuracy of the water vapor inversion between the BDS and the GPS system.The results prove the feasibility of the BDS system in reversing water vapor.(4)The zenith direction precipitable water PWV value is projected through the path integral to the oblique path direction SWV;six uniformly distributed reference stations in Hong Kong are selected,starting from(114.0°E,22.20°N),every 0.05° on the plane.Evenly divide the grid.The vertical direction is unevenly layered,and the number of grids is 200(4 × 5 × 10).The Gaussian weighted smoothing coefficient is used to perform the plane constraint and the vertical constraint using the exponential model.The chromatographic equations are established according to the principle of tomography.The method of least squares and SVD is used to solve the equations of the equation,and the feasibility of the method is verified.