Estimate of higher order ionospheric errors in GNSS positioning
Article first published online: 9 OCT 2008
Copyright 2008 by the American Geophysical Union.
Volume 43, Issue 5, October 2008
How to Cite
2008), Estimate of higher order ionospheric errors in GNSS positioning, Radio Sci., 43, RS5008, doi:10.1029/2007RS003817., and (
- Issue published online: 9 OCT 2008
- Article first published online: 9 OCT 2008
- Manuscript Accepted: 9 JUN 2008
- Manuscript Revised: 15 MAY 2008
- Manuscript Received: 17 DEC 2007
- GNSS positioning;
- signal bending;
- ionospheric correction
 Precise navigation and positioning using GPS/GLONASS/Galileo require the ionospheric propagation errors to be accurately determined and corrected for. Current dual-frequency method of ionospheric correction ignores higher order ionospheric errors such as the second and third order ionospheric terms in the refractive index formula and errors due to bending of the signal. The total electron content (TEC) is assumed to be same at two GPS frequencies. All these assumptions lead to erroneous estimations and corrections of the ionospheric errors. In this paper a rigorous treatment of these problems is presented. Different approximation formulas have been proposed to correct errors due to excess path length in addition to the free space path length, TEC difference at two GNSS frequencies, and third-order ionospheric term. The GPS dual-frequency residual range errors can be corrected within millimeter level accuracy using the proposed correction formulas.