An improved global zenith tropospheric delay model GZTD2 considering diurnal variations
نویسندگان
چکیده
The zenith tropospheric delay (ZTD) is an important atmospheric parameter in the wide application of global navigation satellite systems (GNSS) technology in geoscience. Given that the temporal resolution of the current global zenith tropospheric delay model (GZTD) is only 24 h, an improved model, GZTD2, has been developed by taking the diurnal variations into consideration and modifying the model expansion function. The data set used to establish this model is the global ZTD grid data provided by Global Geodetic Observing System (GGOS) Atmosphere spanning from 2002 to 2009. We validated the proposed model with respect to ZTD grid data from GGOS Atmosphere, which was not involved in modeling, as well as International GNSS Service (IGS) tropospheric product. The obtained results of ZTD grid data show that the global average bias and root mean square (rms) for the GZTD2 model are 0.2 and 3.8 cm, respectively. The global average bias is comparable to that of the GZTD model, but the global average rms is improved by 3 mm. The bias and rms are far better than the EGNOS model and the UNB series models. The testing results from global IGS tropospheric product show the bias and rms (−0.3 and 3.9 cm) of the GZTD2 model are superior to that of GZTD (−0.3 and 4.2 cm), suggesting higher accuracy and reliability compared to the EGNOS model, as well as the UNB series models.
منابع مشابه
ITG: A New Global GNSS Tropospheric Correction Model
Tropospheric correction models are receiving increasing attentions, as they play a crucial role in Global Navigation Satellite System (GNSS). Most commonly used models to date include the GPT2 series and the TropGrid2. In this study, we analyzed the advantages and disadvantages of existing models and developed a new model called the Improved Tropospheric Grid (ITG). ITG considers annual, semi-a...
متن کاملAccuracy Improvement of Tropospheric Delay Interpolation in RTK Networks
The effect of troposphere on the signals emitted from global navigation satellite system (GNSS) satellites, appears as an extra delay in the measurement of the signal traveling from the satellite to receiver. This delay depends on the temperature, pressure, humidity as well as the transmitter and receiver antennas location. In GNSS positioning, tropospheric delay effects on accuracy of differen...
متن کاملGrid Residual Tropospheric Corrections for Improved Differential GPS Positioning Over the Victoria GPS Network (GPSnet)
Tropospheric delay is one of the major error sources in GPS positioning. The delay of radio signals caused by the troposphere can range from 2 m at the zenith to 20 m at lower elevation angles. In a wide area differential system, tropospheric delays are corrected locally by users using an empirical tropospheric model, with or without meteorological observations. This can easily result in residu...
متن کاملImpact of solid Earth tide models on GPS coordinate and tropospheric time series
[1] Unmodelled sub-daily periodic signals can propagate into time series of daily geodetic coordinates and tropospheric estimates at various different frequencies. Geophysical interpretations of geodetic products, particularly at seasonal timescales, can therefore be affected by poorly modelled signals in the geodetic analysis. In this study, we use two solid Earth tidemodels (IERS2003 and IERS...
متن کامل