Acta Geodaetica et Cartographica Sinica ›› 2025, Vol. 54 ›› Issue (12): 2129-2141.doi: 10.11947/j.AGCS.2025.20250226

• Geodesy and Navigation • Previous Articles     Next Articles

The correction method of relativistic effects for GNSS and LEO satellites

Tao GENG1(), Qiang LI1,2(), Lingyue CHENG2, Jingnan LIU1   

  1. 1.GNSS Research Center, Wuhan University, Wuhan 430079, China
    2.School of Geodesy and Geomatics, Wuhan University, Wuhan 430079, China
  • Received:2025-06-04 Revised:2025-12-25 Online:2026-01-15 Published:2026-01-15
  • Contact: Qiang LI E-mail:gt_gengtao@whu.edu.cn;lq_liqiang@whu.edu.cn
  • About author:GENG Tao (1982—), male, PhD, professor, majors in satellite geodesy and procise orbit determination. E-mail: gt_gengtao@whu.edu.cn
  • Supported by:
    The National Natural Science Foundation of China(42374030);The Key-Area Research and Development Program of Guangdong Province(2023B1111050013)

Abstract:

Relativistic effects in satellite navigation stem from the differential motion states between satellites and terrestrial users, manifesting as gravitational frequency shifts and time dilation. These effects are more pronounced for low earth orbit (LEO) satellites due to stronger perturbations from Earth's non-spherical gravity, raising questions about the applicability of existing correction methods. This study reviews the rigorous relativistic correction formula and two approximations used by IGS Analysis Centers and global navigation satellite systems: the traditional formula, which assumes a small orbital eccentricity and only considers Earth's central gravity, and a modified formula that additionally accounts for gravitational perturbations from Earth's higher-order terms. We first evaluate these formulas for GPS, GLONASS, Galileo, and BDS-3 satellites. Subsequently, we analyze the relationship between their correction accuracy and the orbital inclination, semi-major axis, and eccentricity of LEO satellites using simulated and measured data. Results indicate that for MEO satellites (excluding E14/E18), the modified formula reduces the periodic error amplitude from 0.11 ns to 0.05 ns. For BDS-3 IGSO satellites, however, the traditional formula yields a better accuracy of 0.05 ns compared to 0.06 ns from the modified one. For LEO satellites, the accuracy of both formulas decreases significantly and is strongly influenced by orbital parameters. Specifically, correction accuracy decreases with greater orbital inclination, lower orbital altitude, and larger eccentricity, with periodic errors for near-polar LEO satellites reaching up to 1 ns.

Key words: relativistic effect, GNSS, low-orbit satellite, atomic clock, satellite clock offset

CLC Number: