【摘要】 GRACE-FO卫星搭载的激光测距系统（LRI）能够以纳米级的精度测量星间距离，LRI测距误差低频部分最大噪声源来自于TTL耦合噪声.TTL耦合噪声源于卫星姿态变化与质心（CoM）和三面镜顶点（VP）偏差产生的耦合效应.本文采用线性估计模型，并利用卫星在质心定标阶段的机动信号数据，基于不同方向的子机动，采用整体参数估计和独立参数估计共三种参数估计策略，获得了合理的TTL耦合系数，结果表明TTL耦合系数满足200 um·rad^-1的设计指标要求.另外，将TTL耦合系数换算为质心和三面镜顶点（VP-CoM offset）偏差，可间接获得卫星质心偏差估计结果序列，且该结果序列与基于加速度计的估计结果（卫星质心与加速度计检验质量块的偏差，ACC-CoM offset）序列吻合较好，表明该方法可作为GRACE-FO卫星质心偏差估计的补充方法.更多还原

【Abstract】 The Laser Ranging Interferometer（LRI） carried by the GRACE-FO satellite enables nanometer-level precision measurement of intersatellite range. The low-frequency component of LRI ranging errors is primarily attributed to TTL coupling noise. TTL coupling noise arises from the coupling effects of satellite attitude variations with offset of the Center of Mass（CoM） and Vertex Points（VP） of the Triple Mirror Assembly. In this study, a linear estimation model is adopted. By utilizing the maneuver signal data of the satellite during the CoM calibration phase and employing integrated and independent parameter estimation strategies based on sub-maneuvers in different directions, reasonable TTL coupling coefficients are obtained. The results indicate that the TTL coupling coefficients meet the design specification requirement of 200 um·rad^-1. Furthermore, by converting TTL coupling coefficients into VP-CoM offset, indirect estimation of satellite CoM-offset is achieved. The obtained offset sequence aligns well with the results based on accelerometer measurements（the offset between satellite CoM and the accelerometer test mass, ACC-CoM offset）, demonstrating that this method can serve as a supplementary approach for estimating the CoM-offset of GRACE-FO satellite.更多还原