电离层高阶项延迟对GPS载波相位观测值及基线的影响

Effect of High-Order Ionospheric Delay on GPS Carrier Phase Observation and Baseline

为研究电离层高阶项延迟及其影响,采用IGS提供的实测数据与产品,结合具体实验讨论地磁模型、TEC数据模式、GPS频率及测站分布等对电离层高阶项延迟的影响,分析不同TEC获取方式与地磁模型处理模式下的电离层高阶项延迟对基线的影响。实验表明,利用不同方式获取的TEC是影响电离层高阶项延迟的关键因素,其对载波相位观测值的影响可达10.0 mm,对基线的影响甚至达到cm级;地磁场是电离层高阶项延迟的次要影响因素,对载波相位及基线的影响为mm级;电离层高阶项延迟与测站区域有关,在中纬度区域偏差呈现系统性,而在赤道附近偏差呈现偶然性,其对基线的影响主要与基线距离及方位有关。

In order to study the high-order ionospheric delay and its influence,we use actual measurement data of IGS combined with specific experiments to discuss the geomagnetic model,TEC data model,GPS frequency and station distribution and other factors.We analyze the delay of high-order terms of the ionosphere and their influence on the baseline under different TEC acquisition methods and geomagnetic model processing modes.Experimental results show that the TEC obtained by different methods is a key factor affecting high-order ionospheric delay,its influence on carrier phase observations is up to 10.0 mm,and its impact on baseline is even up to cm level.Geomagnetic field is a secondary factor of high-order ionospheric delay.The influence on carrier phase and baseline is at the mm level;high-order ionospheric delay is related to the station area,showing systematic deviation in mid-latitudes,while high-order ionospheric delay near the equator shows occasional characteristics,and its main influence on the baseline is related to the distance and azimuth of the baseline.