In the near future, many more navigation satellites with dual frequency L1 and L5 will be deployed. The increased number of satellites and the possibility of mitigating the ionospheric delay using dual frequency have opened the door to the possible use of RAIM for vertical guidance. For this purpose, several Advanced RAIM (ARAIM) algorithms have been proposed. Extensive simulation studies have ...

The emergence of China's Beidou, Europe's Galileo and Russia's GLONASS satellites has multiplied the number of ionospheric piercing points (IPP) offered by GPS alone. This provides great opportunities for deriving precise global ionospheric maps (GIMs) with high resolution to improve positioning accuracy and ionospheric monitoring capabilities. In this paper, the GIM is developed based on multi...

Three-dimensional water vapor can be reconstructed from Global Navigation Satellite System (GNSS) observations, which can study 3-D profile variations of atmospheric water vapor and climate. However, there is a large uncertainty of water vapor tomography from single GPS system observations due to limited satellites. The rapid development of multi-GNSS, including China’s Beidou Navigation Satell...

In signal-degraded environments such as urban canyons and mountainous area, many GNSS signals are either blocked or strongly degraded by natural and artificial obstacles. In such scenarios standalone GPS is often unable to guarantee a continuous and accurate positioning due to lack (or the poor quality) of signals. The combination of different GNSSs could be a suitable approach to fill this gap...

The main purpose of this article is to evaluate the comprehensive performance two inter-frequency code bias (IFCB) models using undifferenced and uncombined observations. These IFCB estimate parameters for each GLONASS satellite (EG model) a quadratic function frequency channels K (K = −7…6) (QF model). data sampled in 30 s from 140 stations IGS network on 1–7 September 2021, are used study. We...

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