华南陆地时变重力观测数据质量评估  

Data quality assessment of time-varying terrestrial gravity observation in South China

作　　者：杨锦玲 陈石[1,3] 王林海[1] 卢红艳 李红蕾 张贝[1,3] YANG Jinling;CHEN Shi;WANG Linhai;LU Hongyan;LI Honglei;ZHANG Bei(Institute of Geophysics, China Earthquake Administration, Beijing 100081, China;Fujian Earthquake Agency, Fuzhou 350003, China;Beijing Baijiatuan Earth Science National Observation and Research Station, Beijing 100095, China)

机构地区：[1]中国地震局地球物理研究所,北京100081 [2]福建省地震局,福建福州350003 [3]北京白家疃国家地球科学野外观测研究站,北京100095

出　　处：《测绘学报》2021年第3期333-342,共10页Acta Geodaetica et Cartographica Sinica

基　　金：国家重点研发计划(2018YFC0603502,2017YFC1500503);国家自然科学基金(41774090,U1939205);中国地震局地球物理研究所基本科研业务费专项(DQJB19A0121,DQJB20X09);中国地震局地震科技星火计划和震情跟踪项目(XH18023Y,2020010210)。

摘　　要：陆面时变微重力观测常用于监测地壳内部物质变化。仪器不确定性是影响数据质量的重要因素。本文以华南地区2015年至2018年的时变重力观测数据为研究对象,分别从相对重力仪的非线性漂移特征、格值系数变化入手,引入贝叶斯分析方法,量化不确定性来源,并以网内绝对重力观测结果进行交叉检验,评估时变重力数据产品质量。研究表明:华南2015年以来的重力观测质量由于相对重力仪非线性漂移产生的不确定性较弱,格值系数不准确引起的不确定性更大,约为20×10-8 m/s2;通过绝对重力基准约束和贝叶斯优化可以明显提高数据产品精度。本文研究结果对评价陆地重力数据质量,客观地开展重力场变化解释、分析强震孕育和物质变迁等科学问题具有重要的参考价值。The terrestrial time-varying microgravity observation can be used to study the crustal mass transfer.The uncertainty of the gravity instrument is an important factor that can easily affect the data quality of gravity observations.In this paper,we focus on the time-varying gravity dataset from 2015 to 2018 in South China.Based on Bayesian analysis method,we quantify the related uncertainty sources of the gravity instruments,including the nonlinear drift of relative gravimeter and the change of scale factor of gravimeter.Furthermore,the cross-validation of the absolute gravity in-situ observation in network is applied to assess the gravity data results using this new approach.The results show that the uncertainty caused by the scale factor is larger than that caused by nonlinear drift for the relative gravimeters used in the South China survey network.The magnitude can reach up to 20×10-8 m/s2 for gravity change.Nevertheless,this uncertainty can be effectively reduced by means of the Bayesian method and absolute gravity datum control.This study can be used to assess the data quality of terrestrial gravity observation,to understand the causes of gravity change,and analysis the great earthquake preparation and mass transfer,etc.

关 键 词：微重力观测 贝叶斯分析 交叉检验 绝对重力 格值系数 

分 类 号：P223[天文地球—大地测量学与测量工程]