摘要
针对当前高精度地球参考框架动态维持技术研究中,国内外缺少高纬度地区GNSS测站的非线性特征专题研究的现状,采用改进的HHT算法CEEMD和自相关函数准则组合形成一套自适应信噪分析方法,分析了南北半球22个高纬度地区测站的周期特征和噪声特性,并估算了速度场误差。结果显示:N方向具有比E方向更明显的半年周期,垂直方向上,南半球比北半球具有更明显半周年和周年运动,水平方向和垂直方向上分别主要表现为纯白噪声和单纯的闪烁噪声,如果不采用合适的噪声模型,速度误差在水平和垂直方向上可分别低估15.5倍和10~1500倍,北半球受影响高于南半球。研究表明,高纬度地区大部分测站水平方向速度场可仅顾及纯白噪声,但不能忽略有色噪声的个别影响,垂直方向上则应顾及有色噪声的影响。
In the current research on dynamic maintenance technology of high precision earth reference frame,special focus is necessary on the nonlinear characteristics of global navigation satellite system(GNSS)stations in high-latitude regions.In this paper,an adaptive signal-noise analysis method is proposed by combining the complete ensemble empirical mode decomposition(CEEMD)and autocorrelation function criteria.The periodic and noise characteristics of 22high latitude stations in the northern and southern hemispheres are analyzed,and site velocity uncertainties are estimated.Our results show that,semi-annual period is more obvious in the N direction when compared with the E direction,and in the vertical direction,semi-annual period and annual period are more obvious in the southern hemisphere when compared with the northern hemisphere,and sites are dominated by pure white noise and flicker noise in the horizontal direction and the vertical direction respectively.Lack of optimal noise model will make site velocity uncertainties underestimated by a factor of 15.5horizontally and 10~1500vertically,with sites in the northern hemisphere being more affected than the southern hemisphere.Thus just applying the white noise model is credible in the estimation of horizontal velocity field of most stations at high latitude,and the individual effect of colored noise cannot be ignored,but in the vertical direction,colored noise model should be applied.
作者
胡在凰
童小华
刘世杰
袁国志
HU Zaihuang;TONG Xiaohua;LIU Shijie;YUAN Guozhi(College of Surveying and GEO-Informatics,Tongji University,Shanghai 200092,China;Ningbo Institute of Surveying,Mapping and Remote Sensing Technology,Ningbo,Zhejiang 315042,China)
出处
《测绘科学》
CSCD
北大核心
2023年第7期31-38,共8页
Science of Surveying and Mapping
关键词
CEEMD
时间序列
非线性
周期特征
噪声
速度误差
CEEMD
time series
the nonlinear characteristics
periodic characteristics
noise analysis
velocity uncertainties
