Retrieval Of Precipitable Water Vapor Based On BeiDou Satellite Signal And Its Application Research

The technology of global navigation satellite system(GNSS)has been comprehensively developed.The introduction of GNSS related technologies in the meteorological field has high practical value.Precipitable Water Vapor(PWV)is an important parameter of weather forecast.Accurate and rapid acquisition of Precipitable Water Vapor is a hot spot in remote sensing monitoring research.GNSS signal has certain sensitivity to water vapor.The inversion of Precipitable Water Vapor by GNSS signal can make up for the deficiency of traditional meteorological detection methods.At present,many researches have been carried out on the inversion method of Precipitable Water Vapor Based on GNSS signal at home and abroad,but the retrieval of Precipitable Water Vapor is mainly based on GPS signals now.At this stage,China’s BeiDou technology is gaining momentum,using BeiDou signal in more fields is the goal of many researchers in China.Applying BeiDou signal to the retrieval process of Precipitable Water Vapor can provide more choices for the research in this field and promote the further development of this technology.At the same time,with the development of machine learning methods,it provides a good solution for the treatment of nonlinear fitting problems.Compared with the use of traditional empirical models,the prediction model based on machine learning methods can obtain better prediction effect and fitting degree.This paper takes BeiDou signal inversion of Precipitable Water Vapor as the research content,and mainly completes the following work:(1)Through the elaboration of the development of GNSS inversion of Precipitable Water Vapor,this paper analyzes the methods,advantages and disadvantages of traditional atmospheric detection,leads to the advantages of using GNSS meteorological detection technology,summarizes the research status at home and abroad,as well as the current principles and methods of GNSS inversion of Precipitable Water Vapor,and combs the development overview of the research.(2)This paper introduces the process of BeiDou signal inversion of Precipitable Water Vapor and how to use the GAMIT/GLOBK software.And estimates the corresponding Precipitable Water Vapor by interpreting the BDS/GPS signal data of CUSV,IISC,TONG and VILL.The experimental results show that the results and accuracy of the Precipitable Water Vapor estimated by BeiDou signal are highly consistent with those estimated by GPS signal.It also proves the feasibility of using BeiDou signal to estimate the Precipitable Water Vapor.(3)Using the small sample data sets of PWV value,temperature(TD),air pressure(PR)and relative humidity(HR)of TONG Station,a short-term prediction model is constructed based on the Random Forest method,and the effect of the model is tested.The correlation coefficient between the predicted value of the model and the actual value is 0.826,and the mean square error is 7.757 mm.The results show that this method has certain reference significance for the short-term prediction of the region.(4)Through the correlation analysis between PWV value of IISC station obtained from the experiment and O3 concentration in the area from January 15 to 29,2020,it is found that there is basically no correlation between PWV value and O3 concentration in the whole day within this time range.However,when screening PWV value and O3 concentration during the daily radiation is low and the air humidity is high,it is found that there is a negative correlation between PWV value and O3 concentration,and the correlation coefficient is-0.4.