Effect of Earth-Moon’s gravity on TianQin’s range acceleration noise
Xuefeng Zhang, Chengjian Luo, Lei Jiao, Bobing Ye, Huimin Yuan, Lin Cai, Defeng Gu, Jianwei Mei, Jun Luo
Abstract
TianQin is a proposed space-borne gravitational-wave detection mission using circular high Earth orbits. The geocentric concept has raised questions about the disturbing effect of the nearby gravity field of the Earth-Moon system on the highly sensitive intersatellite ranging measurements. Here we examine the issue through high-precision numerical orbit simulations with detailed gravity-field models. By evaluating range accelerations between distant free-falling test masses, the study shows that the majority of the Earth-Moon's gravity disturbances are not in TianQin's detection frequency band above ${10}^{\ensuremath{-}4}\text{ }\text{ }\mathrm{Hz}$, and hence present no showstoppers to the mission.