A new global zenith tropospheric delay model GZTD

作者：Yao Yi-Bin^*; He Chang-Yong; Zhang Bao; Xu Chao-Qian

来源：Acta Geophysica Sinica, 2013, 56(7): 2218-2227.

DOI：10.6038/cjg20130709

• Zenith tropospheric delay
• GZTD model
• EGNOS model
• UNB series model

Troposphere delay is one of the main error sources in global navigation satellite systems (GNSS). Its obvious randomness is mainly attributed to meteorological parameters (total pressure, temperature and water vapor pressure, etc.). In this paper, the temporal and spatial variations of global Zenith Troposphere Delay (ZTD) is analyzed using the time series of global 4D-grid ZTD from 2002 to 2009, provided by Global Geodetic Observing System (GGOS) Atmosphere. According to the analysis, a new global ZTD correction model without requiring meteorological parameters, called GZTD, is developed based on spherical harmonics. Experimental results show that the precision of inner coincidence of GZTD model (bias: 0.2 cm, RMS: 3.7 cm) considering the longitudinal and latitudinal variations of ZTD performs better than other latitude-only models, such as UNB3m (bias: 3.4 cm, RMS: 6.0 cm), UNB4 (bias: 4.7 cm, RMS: 7.4 cm), UNB3 (bias: 4.0 cm,. RMS: 7.0 cm) and EGNOS (bias: 4.5 cm, RMS: 6.9 cm). Compared to ZTD time series from 385 global International GNSS Service (IGS) sites, GZTD model (bias: -0.02 cm, RMS: 4.24 cm) is still clearly superior to other similar models. The GZTD model owns such advantages as well-performance, simplicity in computation and less parameters-requirement.

• 出版日期2013-7
• 单位武汉大学