Analytical performance and validations of the Galileo five-frequency precise point positioning models

Abstract

Galileo navigation satellite system provides global services with five-frequency signals. The contribution of this study is to develop four Galileo five-frequency precise point positioning (PPP) models with the ionospheric-free (IF) and uncombined observables, namely FF1, FF2, FF3 and FF4 models, respectively. Galileo dual- and triple-frequency IF models, known as DF and TF models, are also investigated for comparisons. The Galileo dual- and multi-frequency PPP models are comprehensively evaluated with thirty consecutive days period observations collected from 26 multi-GNSS experiment (MGEX) network stations, together with a dynamic experiment dataset, in terms of the static and kinematic performance. The by-product estimated parameters in five-frequency PPP models including the receiver clock, tropospheric delay, receiver inter-frequency biases (IFBs) and differential code bias (DCB) are also analyzed. The experimental results show that the FF1, FF2, and FF3 models perform basic consistent and the FF4 model exhibits inconsistency due to the external ionospheric constraint. The Galileo kinematic PPP performance is significantly improved with the multi-frequency observations under the limited observed satellites circumstance. The significance and potency of the Galileo five-frequency PPP is demonstrated for future Galileo applications.