基于地面重力的卫星重力梯度检校方法

Calibration of satellite gravity gradients based on ground gravity data

卫星重力梯度仪在轨检校是提高梯度模式重力卫星观测质量的关键.本文面向中国未来梯度模式重力卫星规划任务,研究提出一种基于地面重力的卫星在轨检校方法,该方法顾及卫星设计指标,从地面先验重力数据的精度、空间尺度以及卫星重力梯度仪的观测噪声等卫星检校要素开展分析研究,成功实现地面数据与卫星观测数据的比对检校.研究结果表明,在12°×12°的地面检校区域内,利用精度优于1 mGal的地面重力观测数据即可实现噪声低于10 mE的重力梯度仪高精度在轨检校.

The on-orbit calibration of satellite gravity gradiometer is the key to improving the observation quality of satellite gradiometry.This paper proposes an on-orbit calibration method based on ground gravity data for China's future satellite gravity gradiometry mission.Considering the possible mission requirements,this method analyzes the precision and covered area of a priori ground gravity data,as well as the noise of gradiometer observations.The satellite observations are successfully calibrated based on the ground gravity data.The results show that with ground gravity data in a calibration area of 12°×12°and accuracy better than 1 mGal,noise magnitude of the gradiometer less than 10 mE can be fulfilled for high-precision on-orbit calibration of the gravity gradiometer.