Abstract:There are problems in calculating conventional GPS precipitable water vapor (GPS-PWV), including the large amount of data, low efficiency, and many introduced observation errors. Based on the radiosonde and GPS data collected at Chenzhou CORS station in 2015 and using linear regression and least squares methods, a new direct conversion PWV model is established from radiosonde-derived PWV (RS-PWV), GPS tropospheric delay (GPS-ZTD), ground temperature and atmospheric pressure. The direct conversion PWV model is compared with RS-PWV and GPS-PWV respectively to verify accuracy and reliability. The correlation analysis shows a favorable linear relationship between RS-PWV and GPS-ZTD, with the correlation coefficient reaching 0.927 6. The RS-PWV has positive and negative correlation with the 4-order fitting temperature and atmospheric pressure; their correlation coefficient reaches 0.640 1 and -0.626 3 respectively. The correlation coefficient between single-order single-factor model PWV based on ZTD and GPS-PWV is 0.969 9, which shows the feasibility of directly calculating PWV from ZTD. The accuracy of single-order multi-factor model based on ZTD, temperature and atmospheric pressure is significantly higher than that of single-order single-factor model based on ZTD, and RMS is increased from 4.3 mm to 3.3 mm.Therefore, the accuracy of direct conversion PWV model is slightly lower than that of GPS-PWV, but it simplifies computation and improves efficiency.
LI Li,SONG Yue,YI Jinhua et al. Study on the Direct Conversion Model Between Tropospheric Delay and Precipitable Water Vapor[J]. jgg, 2019, 39(5): 492-495.