Testing General Relativity with LAGEOS, LAGEOS II and Ajisai laser-ranged satellites

TL;DR

This paper discusses using Satellite Laser Ranging data from LAGEOS, LAGEOS II, and Ajisai satellites to measure relativistic effects predicted by General Relativity, aiming to improve accuracy and constrain PPN parameters.

Contribution

It introduces a method to enhance measurement accuracy of relativistic effects using multiple satellites and ranging data, reducing systematic errors in testing General Relativity.

Findings

Current measurement error for gravitomagnetic effect is 12.92%.

Including Ajisai data reduces error to 10.78%.

Potential to improve PPN parameter constraints significantly.

Abstract

The accuracy reached in the past few years by Satellite Laser Ranging (SLR) allows for measuring even tiny features of the Earth's gravitational field predicted by Einstein's General Relativity by means of artificial satellites. The gravitomagnetic dragging of the orbit of a test body is currently under measurement by analyzing a suitable combination of the orbital residuals of LAGEOS and LAGEOS II. The lower bound of the error in this experiment amount to 12.92%. It is due to the mismodeling in the even zonal harmonics of the geopotential which are the most important sources of systematic error. A similar approach could be used in order to measure the relativistic gravitoelectric pericenter shift in the field of the Earth with a lower bound of the systematic relative error of 0.6% due to the even zonal harmonics as well. The inclusion of the ranging data to the Japanese passive geodetic satellite Ajisai would improve such limits to 10.78% and 0.08% respectively and would allow to improve the accuracy in the determination of the PPN parameters beta and gamma.