The effect of the second-order ionospheric term on GPS positioning in Antarctica

• Published in: Arctic, Antarctic, and Alpine Research
• Main Authors: Hang Li, Zemin Wang, Xiangbin Cui, Jingxue Guo, Lin Li, Bo Sun
• Format: Article in Journal/Newspaper
• Language: English
• Published: Taylor & Francis Group 2020
• Subjects: ionosphere; second-order ionospheric term; gps positioning; antarctica; Environmental sciences; GE1-350; Ecology; QH540-549.5; Antarctic; The Antarctic; Antarc*; Antarctic and Alpine Research; Antarctica; Arctic
• Online Access: https://doi.org/10.1080/15230430.2020.1742062; https://doaj.org/article/17c2b995c8974d4e9f4d33c6fd7bf5ea

Global Positioning System (GPS) signals are delayed when passing through the ionosphere due to an ionospheric refraction effect. The ionospheric-free linear combination of GPS signals can eliminate most of the error caused by the first-order ionospheric term. However, the influence of higher-order ionospheric terms remains, and it should be accounted for when conducting high-precision geodetic applications. In this study, we use data from twenty-one GPS continuous operating stations from different observing networks distributed in Antarctica and analyze the effect of the second-order ionospheric term on GPS positioning during the whole year for 2012. Results show that the effect on these stations is at the level of submillimeters to millimeters, and the effect in summer is several times higher than it is in winter. In addition, this effect is found to be positively correlated to the change of the total electron content over the Antarctic continent. On the other hand, all of the stations show the southward and upward movements derived from the effect. The common and seasonal displacement trends displayed in the Antarctic region should not be ignored in future high-precision research or applications but should be brought to attention, especially when total electron content in the ionosphere is high.