关键词: GPS测量误差, 对流层延时, 电离层延时, 卫星仰角

Abstract: GPS measurement error mainly comes from three sources：measurement error introduced by satellite，measurement error introduced by receiver itself and measurement error introduced by atmospheric delay.Atmospheric delay error mainly includes ionospheric delay and tropospheric delay，which has certain stability and can be predicted by mathematical model.The ionospheric delay is related to the electron density，which is generally several meters.When the electron density increases dramatically，it can reach tens of meters.The tropospheric delay is about several meters in the zenithal direction.And it can reach tens of meters when the height Angle is low，which seriously affects the GPS measurement and positioning accuracy.Therefore，the effective prediction of atmospheric delay error is of great significance to improve GPS measurement and positioning accuracy.In this paper，the atmospheric delay error prediction model was introduced，and the influence of satellite elevation Angle on the atmospheric delay error variation was analyzed through data analysis.

Key words: GPS measurement error, Ionospheric delay, Tropospheric delay, Satellite elevation