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Xinmei Liang

Bio: Xinmei Liang is an academic researcher. The author has an hindex of 1, co-authored 1 publications receiving 2 citations.

Papers
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DOI
24 Jun 2022
TL;DR: In this paper , the rate of total electron content index (ROTI) parameter was incorporated into the EAS model to mitigate severe storm effects on GNSS PPP, which improved the PPP accuracy in 3D direction by approximately 12.9% to 14.7%.
Abstract: For global navigation satellite system (GNSS), ionospheric disturbances caused by the geomagnetic storm can reduce the accuracy and reliability of precision point positioning (PPP). At present, common stochastic models in GNSS PPP, such as the elevation angle stochastic (EAS) model or carrier‐to‐noise power‐density ratio ( C/N0 $C/{N}_{\mathit{0}}$ ) based SIGMA‐ ε $\varepsilon $ model, do not properly consider storm effects on GNSS measurements. To mitigate severe storm effects on GNSS PPP, this study further implements the rate of total electron content index (ROTI) parameter into the EAS model referred to as the EAS‐ROTI model. This model contains two operations. The first one is to adjust variance of GNSS measurements using ROTI observations on EAS model. The second one is to determine the ratio of the priori variance factor between pseudorange and carrier phase measurements during severe storm conditions. The performance of EAS‐ROTI model is verified by using a large number of international GNSS service stations datasets on 17 March and 23 June in 2015. Experimental results indicate that on a global scale, the EAS‐ROTI model improves the PPP accuracy in 3D direction by approximately 12.9%–14.7% compared with the EAS model, and by about 24.8%–45.9% compared with the SIGMA‐ ε $\varepsilon $ model.

2 citations


Cited by
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DOI
01 Jan 2023
TL;DR: In this article , the rate of change of total electron content index (ROTI) theory is employed as a diagnosis method for trigging instabilities in the ionosphere, and the main controlling factors of the chemical release are investigated.
Abstract: The chemical release for trigging instabilities is a challenging topic in the ionosphere since 1970s. It is a helpful tool to both recognize the physical mechanism for modeling space weather and mitigate adverse effects on technological systems. Based on the well‐developed instability simulation, the rate of change of total electron content index (ROTI) theory is employed as a diagnosis method in this paper. It is used to study the instability inducing effects or scintillation controlling effect of chemical release for the first time. The main controlling factors of the chemical release are investigated. It is found that the release amount, release altitude and the initial growth rate of the ambient ionosphere are of great importance to the instability evolution and consequent scintillation effects. First, the plasma bubble induced by chemical release will rise and penetrate to the upper ionosphere, no matter what the ambient growth rate is. However, the ambient growth rate will determine the induced scintillation regime. Second, the release altitude will significantly affect the instability evolving time and scintillation intensity. There only exist a threshold of the release amount for moderate scintillation. Finally, the release amount could dominate the bifurcation process, in which the plasma bubble will deform and extend laterally. It provides an insight into the scintillation effect induced by chemical release by using the ROTI estimation. As a result, this work is a step further for the challenging topic of chemical release, and so as to be helpful for the follow‐up active space experiments.