The satellite attitude error is transmitted to the gravity field through KBR antenna phase center correction and non-conservative force conversion, which affects the accuracy of gravity field inversion. Therefore, obtaining high-precision satellite attitude is one of the important research contents of gravity field inversion. Each satellite of GRACE-FO is equipped with three SCs and an IMU for satellite attitude measurement, and fusion of these two types of data can obtain high-precision satellite attitude. In this paper, we use kalman filter to fuse the original GRACE-FO 1A observation data, and take into account the calibration of the installation matrix of the SCs during the fusion process. Meanwhile, a quaternion integrator that takes angle increments as inputs is derived from the equivalent rotation vector differential equation to address the computational inefficiency of first-order quaternion integrator, the accuracy and computational efficiency are verified using measured data. The experimental results show that after the calibration of the installation matrix of the SCs, the system bias of caused by switching from three SCs observations to two SCs observations can be eliminated. The standard deviation of the attitude difference between the obtained attitude in this paper and the attitude calculated by JPL is at most and the proposed incremental quaternion integrator has the same accuracy as the first-order quaternion integrator but with computational efficiency improved by at least 35%.

中文翻译：

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GRACE-FO姿态确定：星相机安装矩阵标定和增量四元数积分器


卫星姿态误差通过KBR天线相位中心校正和非保守力转换传递到重力场，影响重力场反演的精度。因此，获取高精度卫星姿态是重力场反演的重要研究内容之一。 GRACE-FO的每颗卫星都配备了3个SC和1个IMU用于卫星姿态测量，这两类数据的融合可以获得高精度的卫星姿态。本文采用卡尔曼滤波器对原始GRACE-FO 1A观测数据进行融合，并在融合过程中考虑了SC安装矩阵的校准。同时，针对一阶四元数积分器计算效率低的问题，从等效旋转矢量微分方程推导了以角度增量为输入的四元数积分器，并用实测数据验证了精度和计算效率。实验结果表明，对SC安装矩阵进行标定后，可以消除由3个SC观测切换为2个SC观测带来的系统偏差。本文获得的姿态与JPL计算的姿态之间的姿态差标准差最大为 ，所提出的增量四元数积分器具有与一阶四元数积分器相同的精度，但计算效率提高了至少35% 。