GNSS垂向坐标时间序列周年项振幅的时变特征及成因分析  

Time-varying characteristics and cause analysis of annual amplitudes of GNSS vertical coordinate time series

作　　者：贾彦锋 朱新慧[1] 孙付平[1] 肖凯[1] 柯能 JIA YanFeng;ZHU XinHui;SUN FuPing;XIAO Kai;KE Neng(Institute of Geospatial Information,Information Engineering University,Zhengzhou 450000,China;Key Lab of Spacecraft In-Orbit Fault Diagnosis and Maintenance,Xi′an Satellite Control Center,Xi′an 710043,China)

机构地区：[1]信息工程大学地理空间信息学院,郑州450000 [2]西安卫星测控中心航天器在轨故障诊断与维修重点实验室,西安710043

出　　处：《地球物理学报》2023年第1期162-172,共11页Chinese Journal of Geophysics

基　　金：国家自然科学基金(41804018)资助.

摘　　要：GNSS坐标时间序列中季节性信号的振幅表现出明显的时变特性.本文从全球范围内选取了468个GNSS测站的垂向坐标时间序列数据,对周年项振幅的时变特征和原因进行了深入探究.首先坐标时间序列数据在经过带通滤波后,进行分段最小二乘拟合,得到随时间变化的周年项振幅,并在此基础上,分析了振幅变化的量级大小和特点,发现全球测站周年振幅变化的平均幅度在1 mm左右,并且振幅的波动性具有明显的时空分布特征,忽略这种时变特性最大会造成2~3 mm的周年项残留.然后从环境负载和热膨胀效应入手分析了周年项振幅变化的原因及其对周年项振幅变化的贡献,发现环境负载和热膨胀位移与GNSS垂向坐标之间周年振幅变化的平均一致性在60%左右,而且经过两者改正分别有68%和76%的测站周年项振幅波动幅度出现了下降,由此提出环境负载和热膨胀效应是周年项振幅变化的重要原因.同时经过分析发现GNSS数据处理模型和策略也会引起周年项振幅的变化.The amplitudes of seasonal signal in GNSS coordinate time series shows obvious time-varying characteristics.In this paper,the vertical coordinate time series of 468 GNSS stations around the world are selected to deeply explore the time-varying characteristics and cause of annual amplitudes.First,after band-pass filtered,the time series are fitted by piecewise least squares to get the time-varying amplitudes of the annual signal.Then,the magnitude and characteristics of amplitude variation are analyzed.It is found that the average magnitude of annual amplitude changes is about 1 mm.Moreover,the fluctuation of amplitude has obvious temporal and spatial distribution characteristics.Ignoring this time-varying characteristic will lead to a maximum annual residue of 2~3 mm.Then,we deeply investigate the contributions of the environmental loading and thermal expansion effects to the annual amplitude changes.The result shows it is about 60%that the average consistency of amplitude changes between the GNSS vertical coordinates and displacement caused by environmental loading and thermal expansion,and that after the two corrections,about 68%and 76%of the stations have a decrease in the annual amplitude fluctuation respectively.It is suggested that the environmental loading and thermal expansion effects are the important reasons for the amplitude variation of the annual signal.Meanwhile,we find that the GNSS data processing model and strategy will also cause the change of annual amplitudes.

关 键 词：振幅时变特征 GNSS坐标时间序列 非线性变化 环境负载 热膨胀效应 

分 类 号：P228[天文地球—大地测量学与测量工程]