联合星象仪四元数的卫星重力梯度测量角速度重建方法  

Reconstruction Method of Satellite Gravity Gradient Measurement Angular Velocity by Combining Star Tracker Quaternion

作　　者：郭泽华 吴云龙[1,2,3] 肖云 胡敏章[1,2] GUO Zehua;WU Yunlong;XIAO Yun;HU Minzhang(Institute of Seismology,China Seismological Bureau,Wuhan 430071,China;Key Laboratory of Seismic Geodesy,China Seismological Bureau,Wuhan 430071,China;College of Disaster Prevention Science and Technology,College of Geological Engineering,Sanhe 065201,China;Xi’an Research Institute of Surveying and Mapping,Xi'an 710054,China)

机构地区：[1]中国地震局地震研究所,湖北武汉430071 [2]中国地震局地震大地测量重点实验室,湖北武汉430071 [3]防灾科技学院地质工程学院,河北三河065201 [4]西安测绘研究所,陕西西安710054

出　　处：《武汉大学学报（信息科学版）》2021年第9期1336-1344,共9页Geomatics and Information Science of Wuhan University

基　　金：科技部重点研发计划(2018YFC1503503-1);国家自然科学基金(41931074,41974096)。

摘　　要：在卫星重力梯度测量的level 1b (L1b)数据处理过程中,为了计算得到高精度的重力梯度,需精确测定卫星姿态角速度。在星象仪姿态数据坐标系转换中,单星象仪中的低精度角速度分量会将噪声传递到其他角速度分量,进而影响整个重力梯度的计算精度。基于星象仪噪声特性,构建星象仪各轴的噪声分布加权矩阵,对两个或多个星象仪的姿态四元数联合求解最佳姿态四元数,为后续角速度恢复提供精确姿态控制。计算结果表明,多星象仪联合解算得到的卫星姿态角速度在整个功率谱密度上实现了显著改善。与单星象仪计算方法相比,多星象仪联合得到的最佳姿态角速度wy、wz在10~100 mHz内精度约提升1个量级,噪声水平约达到10-6rad/s量级,能够有效抑制低精度角速度分量在坐标系转换中导致的噪声传播。此外,基于多星象仪联合方法计算得到的重力梯度迹值的功率谱密度,相比单星象仪方法也有较为显著的改善。Objectives: In order to calculate the high precision gravity gradient in level 1 b(L1 b) data processing of gravity field and steady-state ocean circulation explorer(GOCE) satellite, it is necessary to accurately measure the satellite attitude angular velocity. In the coordinate system transformation of the attitude data of astrology, the low precision angular velocity components of a single astrology instrument will transmit the noise to other angular velocity components, which will affect the calculation accuracy of the whole gravity gradient.Methods: In this paper, based on the noise characteristics of the astrological instrument, the weighted matrix of the noise distribution on each axis of the astrological instrument is constructed,and the optimal attitude quaternion is solved jointly for the attitude quaternion of two or more astrological instruments, so as to provide accurate attitude control for subsequent angular velocity recovery. Results:Compared with the single astro-meter calculation method, the accuracy of the optimal attitude angular velocity components wy and wzobtained by the combination of multiple astro-meters can reach about 1 order of magnitude higher within 10-100 mHz, and the noise level is up to 10-6 rad/s, which can effectively suppress the noise propagation caused by the low precision angular velocity components in coordinate system transformation.Conclusions: The results show that the satellite attitude angular velocity calculated by the combination of multiple astrological instruments can be significantly improved in the whole power spectral density, the power spectral density of gravity gradient trace values calculated by the combined method of multiple astrologers is also significantly improved compared with the single astrologer method.

关 键 词：卫星重力梯度 星象仪 四元数校准 姿态四元数组合 

分 类 号：P223[天文地球—大地测量学与测量工程]