Quality Analysis of GNSS/MET Water Vapor Observation Data in Hainan Province

In the report， based on the observation data files， navigation files， temperature， humidity and air pressure data of five GNSS/MET water vapor content observation stations in Hainan Province， the probability density function （PDF）， histogram and box plot analysis methods were used to analyze the data quality characteristics of 10 variables in 2020. The results showed that： （1） the number of navigation satellites tracked by Wuzhishan station is less than that tracked by other stations， and the number of outliers of Wuzhishan station is more than that of other stations. （2） The Doppler frequency histograms of L1 and L2 carriers at Xisha station are bimodal， and whose quality is inferior to that of other stations. （3） The L1 and L2 carrier phase data of Xisha station are quite different from that of other stations， and the L2 carrier phase histogram of Xisha station has obvious bimodal shape. （4） The histogram of L2 carrier signal-to-noise ratio variable value of Xisha station has obvious bimodal shape， and the box of box line graph is larger than that of other stations， and the data fluctuation is larger. （5） The histogram of L1 carrier C/A code pseudo range and L2 carrier P code pseudo range at Xisha station has obvious bimodal shape， and the median of its boxplot is quite different from that of other stations. （6） The calculated water vapor content of each observation station in the whole province is about 50 mm.