测绘学报 ›› 2018, Vol. 47 ›› Issue (3): 291-297.doi: 10.11947/j.AGCS.2018.20170219

• 大地测量学与导航 •    下一篇

GOCE卫星重力梯度校准与无阻尼控制效果分析

邹贤才1,2   

  1. 1. 武汉大学测绘学院, 湖北 武汉 430079;
    2. 地球空间信息技术协同创新中心, 湖北 武汉 430079
  • 收稿日期:2017-04-27 修回日期:2017-12-20 出版日期:2018-03-20 发布日期:2018-03-29
  • 作者简介:邹贤才(1978-),男,博士,教授,主要从事空间大地测量和物理大地测量方面的研究。E-mail:xczou@whu.edu.cn
  • 基金资助:
    国家自然科学基金(41274033);测绘地理信息公益性行业科研专项(201512001);国家重点基础研究发展计划(973计划)(2013CB733301)

Calibration of the Satellite Gravity Gradients for GOCE and Analysis on Its Drag Free Control System

ZOU Xiancai1,2   

  1. 1. School of Geodesy and Geomatics, Wuhan University, Wuhan 430079, China;
    2. Collaborative Innovation Center for Geospatial Technology, Wuhan 430079, China
  • Received:2017-04-27 Revised:2017-12-20 Online:2018-03-20 Published:2018-03-29
  • Supported by:
    The National Natural Science Foundation of China(No. 41274033);Special Fund for Public Welfare Industry (Surveying, Mapping and Geoinformation)(No. 201512001);National Key Basic Research Program of China(No. 2013CB733301)

摘要: GOCE卫星是首颗搭载高精度梯度仪,通过加速度计差分测量确定地球重力场的现代重力卫星。该卫星设计为无阻尼飞行状态(沿轨方向),加速度计并未安置在卫星质心,这些特点使得GOCE与标准的卫星跟踪卫星重力测量模式有着显著的区别。本文首先指出GOCE任务中普通模式加速度校准存在不严密性问题,并提出了分别校准6个加速度计,分离偏差参数的方案。利用GOCE任务期内的几何法精密轨道,采用动力法完成校准,并分析了无阻尼控制的效果,发现:①虽然GOCE所在轨道高度的中性大气密度较GRACE高两到三个量级,但GOCE卫星在沿轨方向的残余非保守力比GRACE卫星的对应分量小一个量级,充分显示了无阻尼控制系统的补偿效果;②通过精密轨道内插的轨道速度与动力法轨道速度的比较可以得出,卫星无阻尼控制系统对GOCE卫星速度的显著影响;③计算了GOCE卫星所受的非保守力。获得了GOCE任务期间的加速度计校准参数,并讨论了利用其辅助重力梯度仪数据预处理的可能方法。

关键词: 卫星重力, 引力梯度, GOCE, 非保守力, 动力法

Abstract: GOCE is the first modern satellite, which carried a gravity gradiometer measuring the earth gravity filed with high accuracy by the differential measurements of the accelerometers. Its along track is in a drag-free status and the accelerometers are off-center mounted. These characteristics make GOCE a significant difference from the standard satellite-satellite tracking (SST) technique. In this paper, the problem of non-strictness in the common mode acceleration calibration of GOCE is pointed out first and, then the schemes to calibrate six accelerometers individually to separate the bias parameters are presented. The precise kinematic orbit of GOCE is used in the accelerometer calibration and drag-free control system evaluation by the dynamics method. Some fundamental results are achieved. Firstly, although the neutral atmosphere density at the altitude of GOCE orbit is higher than that of GRACE satellites with two to three orders of magnitude, the residual non-conservative force of the GOCE satellite along the track is one order of magnitude lower than the corresponding component of the GRACE satellites, which shows the compensation effect of the drag-free control system fully. Secondly, it can be concluded that the drag-free control system has a significant effect on the determination of GOCE's velocity by comparing the orbital velocity interpolated from the position and integrated with the orbit dynamics. Thirdly, the non-conservative force acting on GOCE satellite is analyzed and the accelerometer calibration parameters are estimated and evaluated. The possible developments on the preprocessing of the satellite gravity gradients with the accelerometer calibration results are also discussed in this paper.

Key words: satellite gravimetry, gravity gradients, GOCE, non-conservative force, dynamic method

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