郭泽华, 吴云龙, 肖云, 胡敏章. 联合星象仪四元数的卫星重力梯度测量角速度重建方法[J]. 武汉大学学报 ( 信息科学版), 2021, 46(9): 1336-1344. DOI: 10.13203/j.whugis20200595
引用本文: 郭泽华, 吴云龙, 肖云, 胡敏章. 联合星象仪四元数的卫星重力梯度测量角速度重建方法[J]. 武汉大学学报 ( 信息科学版), 2021, 46(9): 1336-1344. DOI: 10.13203/j.whugis20200595
GUO Zehua, WU Yunlong, XIAO Yun, HU Minzhang. Reconstruction Method of Satellite Gravity Gradient Measurement Angular Velocity by Combining Star Tracker Quaternion[J]. Geomatics and Information Science of Wuhan University, 2021, 46(9): 1336-1344. DOI: 10.13203/j.whugis20200595
Citation: GUO Zehua, WU Yunlong, XIAO Yun, HU Minzhang. Reconstruction Method of Satellite Gravity Gradient Measurement Angular Velocity by Combining Star Tracker Quaternion[J]. Geomatics and Information Science of Wuhan University, 2021, 46(9): 1336-1344. DOI: 10.13203/j.whugis20200595

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

  • 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wywz在10~100 mHz内精度约提升1个量级,噪声水平约达到10-6 rad/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。

     

    Abstract:
      Objectives  In order to calculate the high precision gravity gradient in level 1b (L1b) 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 wz obtained 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.

     

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