Abstract
Solar activity and geomagnetic storm cause ionospheric disturbance and affect the GNSS positioning accuracy, which this effect cannot be ignored. The reliability depends mainly on differential code bias (DCB), when estimating the total electron content (TEC) with GNSS pseudorange observations. This study analyzes the variation characteristics of receiver DCB (RDCB) during a strong geomagnetic storm to determine whether the RDCB estimation is affected by space weather. Results show that the RDCB dispersion of low-latitude stations is larger than that of other areas. On the storm day, the RDCB standard deviation (STD) exhibits a peak characteristic and the number of RDCB abnormal stations is significantly more than that on quiet day. Analysis shows that the RDCB abnormality is caused by the ionospheric model misalignment during the ionospheric disturbance. By correcting the RDCB, the RDCB STD is reduced by 43.10%. Thus, the model correction can improve the estimation accuracy of RDCB during geomagnetic storm.
Acknowledgements
The authors would like to thank the editors and the two anonymous reviewers for their valuable comments which have been very helpful in revising the first version. The results presented in this paper rely on data collected at magnetic observatories, so we thank for International association of geomagnetism and upper atmosphere physics (IAGA) provide high standards of geomagnetic index for this research. We would like to thank to the International GNSS Service (IGS) for providing DCB and GIM data.
Disclosure statement
In accordance with Taylor & Francis policy and my ethical obligation as a researcher, we are reporting that we have no conflict of interest exits in the submission of this manuscript.
Notes on contributors
Jianfeng Li, received his master degree of geodesy and survey engineering from Southeast University in 2013. Currently, he is working toward the doctoral degree at Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University. His main interests are GNSS ionospheric sounding and space weather.
Dingfa Huang, is a Professor at Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, China. He obtained his BSc and MSc from the School of Surveying and Mapping, Wuhan University and Ph.D. degree from Southwest Jiaotong University. His research interests are GNSS Satellite Navigation, Space Geodesy, and Emergency Decision Making Support.
Yinghao Zhao, received master degree from Southwest Jiaotong University in 2014 and currently works as a Ph.D. candidate at Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University. His main interests are Satellite navigation and precise point positioning.
Abubakr Hassan, is lecturer at Surveying Department in Karary University, Sudan. He received his master degree in Geodetic Surveying from Sudan University of Science and Technology, Sudan. Currently, he is a PhD candidate at Surveying and Mapping Engineering department in Southwest Jiaotong University, China. His current study about the geodetic crustal deformations associated with massive earthquakes using GNSS measurements.