Analysis of the Geocenter Motions Based on Satellite Measurements

The Earth’s center of mass (CM) is defined in the satellite orbit dynamics as the center of mass of the entire Earth system, including the solid earth, oceans, cryosphere and atmosphere. The geocenter is used to describe Earth’s motion in inertial space and serves as the orbital center for all Earth satellites. The term “geocenter motion” is defined as the motion of the CM with respect to the center of figure (CF) of the solid Earth surface. Satellite Laser Ranging (SLR) provides accurate and unambiguous range measurements to geodetic satellites to determine variations in the vector from the origin of the ITRF to the CM. In the last 15 years, there have been vast improvements in geophysical fluid modeling and in the global coverage, densification, and accuracy of geodetic observations. In this work analyzes the geocenter motions based on ILRS data.