Analysis of the global T m–T s correlation and establishment of the latitude-related linear model
- 108 Downloads
In this study, the correlation between T m, a key variable in GNSS water vapor inversion, and surface temperature (T s) was calculated on a global scale based on the global geodetic observing system (GGOS) atmosphere T m data and European centre for medium-range weather forecasts (ECMWF) surface temperature data. The results show that their correlation is mainly affected by latitudes, and the correlation is stronger at high latitudes and weaker at low latitudes. Although the correlation is relatively weak in the tropic areas, the temperature changes so little in a year in these areas that we can still achieve good T m results by linear regression model. Based on these facts, “GGOS atmosphere” T m data and ECMWF T s data from 2005 to 2011 were used to establish the global latitude-related linear regression model. The new model has root mean square error (RMSE) of 3.2, 3.3, and 4.4 K, respectively, compared with respect to the “GGOS atmosphere” data, COSMIC data, and radiosonde data and is more accurate than the Bevis T m–T s relationship.
KeywordsCorrelation Linear regression Zenith wet delay Water vapor GPS
Thank the ECMWF for providing surface temperature data and “GGOS atmosphere” for providing global T m data.
- 9.Chen JY (1998) On the error analysis for the remote sensing of atmospheric water vapor by ground based GPS. Acta Geod Cartrogr Sin 27:114–118Google Scholar
- 10.Li JG, Mao JT, Li CC (1999) The approach to remote sensing of water vapor based on GPS and linear regression T m in eastern region of China. Acta Meteorol Sin 57:284–291Google Scholar
- 14.Wang Y, Liu LT, Xu HZ et al (2007) Retrieving change of precipitable water vapor in Chinese Mainland by GPS technique. Geom Inf Sci Wuhan Univ 32:152–154Google Scholar
- 15.Jade S, Vijayan MSM (2008) GPS-based atmospheric precipitable water vapor estimation using meteorological parameters interpolated from NCEP global reanalysis data. J Geophys Res 113:1–12Google Scholar