The precise correction of atmospheric zenith tropospheric delay(ZTD)is significant for the Global Navigation Satellite System(GNSS)performance regarding positioning accuracy and convergence time.In the past decades,ma...The precise correction of atmospheric zenith tropospheric delay(ZTD)is significant for the Global Navigation Satellite System(GNSS)performance regarding positioning accuracy and convergence time.In the past decades,many empirical ZTD models based on whether the gridded or scattered ZTD products have been proposed and widely used in the GNSS positioning applications.But there is no comprehensive evaluation of these models for the whole China region,which features complicated topography and climate.In this study,we completely assess the typical empirical models,the IGGtropSH model(gridded,non-meteorology),the SHAtropE model(scattered,non-meteorology),and the GPT3 model(gridded,meteorology)using the Crustal Movement Observation Network of China(CMONOC)network.In general,the results show that the three models share consistent performance with RMSE/bias of 37.45/1.63,37.13/2.20,and 38.27/1.34 mm for the GPT3,SHAtropE and IGGtropSH model,respectively.However,the models had a distinct performance regarding geographical distribution,elevation,seasonal variations,and daily variation.In the southeastern region of China,RMSE values are around 50 mm,which are much higher than that in the western region,approximately 20 mm.The SHAtropE model exhibits better performance for areas with large variations in elevation.The GPT3 model and the IGGtropSH model are more stable across different months,and the SHAtropE model based on the GNSS data exhibits superior performance across various UTC epochs.展开更多
对流层延迟误差与信号频率无关,且具有较强的随机性,是GNSS导航定位中的主要误差源之一。以GGOS Atmosphere发布的格网数据作为真值,从纬度、高程及时间特性3个方面分析了两种全球天顶对流层延迟ZTD(Zenith Total Delay)模型(UNB模型和E...对流层延迟误差与信号频率无关,且具有较强的随机性,是GNSS导航定位中的主要误差源之一。以GGOS Atmosphere发布的格网数据作为真值,从纬度、高程及时间特性3个方面分析了两种全球天顶对流层延迟ZTD(Zenith Total Delay)模型(UNB模型和EGNOS模型)的时空特征,为GNSS导航定位中模型选择的正确性与合理性提供参考依据。分析得出:在纬度方向,ZTD值的RMSE和Bias从南到北呈现递减趋势且逐渐趋于稳定,建议计算ZTD时在南半球通过格网插值,北半球采用UNB模型;在高程方向,ZTD值与高程值呈现出反比关系,EGNOS的残差值较UNB残差值分布更加均匀且规律性较强,可利用高程值进行建模修正;在时间特征方面,ZTD单天内变化较小,两模型互差在mm级且表现出一定的季节性特征。展开更多
基金supported by the National Natural Science Foundation of China(42204022,52174160,52274169)Open Fund of Hubei Luojia Laboratory(230100031)+2 种基金the Open Fund of State Laboratory of Information Engineering in Surveying,Mapping and Remote Sensing,Wuhan University(23P02)the Fundamental Research Funds for the Central Universities(2023ZKPYDC10)China University of Mining and Technology-Beijing Innovation Training Program for College Students(202302014,202202023)。
文摘The precise correction of atmospheric zenith tropospheric delay(ZTD)is significant for the Global Navigation Satellite System(GNSS)performance regarding positioning accuracy and convergence time.In the past decades,many empirical ZTD models based on whether the gridded or scattered ZTD products have been proposed and widely used in the GNSS positioning applications.But there is no comprehensive evaluation of these models for the whole China region,which features complicated topography and climate.In this study,we completely assess the typical empirical models,the IGGtropSH model(gridded,non-meteorology),the SHAtropE model(scattered,non-meteorology),and the GPT3 model(gridded,meteorology)using the Crustal Movement Observation Network of China(CMONOC)network.In general,the results show that the three models share consistent performance with RMSE/bias of 37.45/1.63,37.13/2.20,and 38.27/1.34 mm for the GPT3,SHAtropE and IGGtropSH model,respectively.However,the models had a distinct performance regarding geographical distribution,elevation,seasonal variations,and daily variation.In the southeastern region of China,RMSE values are around 50 mm,which are much higher than that in the western region,approximately 20 mm.The SHAtropE model exhibits better performance for areas with large variations in elevation.The GPT3 model and the IGGtropSH model are more stable across different months,and the SHAtropE model based on the GNSS data exhibits superior performance across various UTC epochs.
文摘对流层延迟误差与信号频率无关,且具有较强的随机性,是GNSS导航定位中的主要误差源之一。以GGOS Atmosphere发布的格网数据作为真值,从纬度、高程及时间特性3个方面分析了两种全球天顶对流层延迟ZTD(Zenith Total Delay)模型(UNB模型和EGNOS模型)的时空特征,为GNSS导航定位中模型选择的正确性与合理性提供参考依据。分析得出:在纬度方向,ZTD值的RMSE和Bias从南到北呈现递减趋势且逐渐趋于稳定,建议计算ZTD时在南半球通过格网插值,北半球采用UNB模型;在高程方向,ZTD值与高程值呈现出反比关系,EGNOS的残差值较UNB残差值分布更加均匀且规律性较强,可利用高程值进行建模修正;在时间特征方面,ZTD单天内变化较小,两模型互差在mm级且表现出一定的季节性特征。
