Determination of Seasonal Variations of Low-Degree Earth Gravity Field from CHAMP Geometric Orbits
Based on satellite dynamics, 1 year’s CHAMP geometric precise orbit data are used in this paper to fit the satellite orbits by Cowell II numerical integral and partitioned Bayesian least square parameter estimation. Time series of low degree geopotential coefficients and are respectively calculated, which reflects obviously seasonal variations of and . The results / month, /month indicate the geodynamical shape of the earth is getting rounder and rounder and at the same time its pear-shaped component adds gradually.
X. Liu et al., "Determination of Seasonal Variations of Low-Degree Earth Gravity Field from CHAMP Geometric Orbits", Applied Mechanics and Materials, Vols. 90-93, pp. 2864-2868, 2011