Power-law Spectrum Analysis on Uncertainties of Rate Estimated from GPS Coordinates Time Series
The ground station velocity derived from GPS coordinates time series is one of the important elements for assessing the stability of the global reference frame.Precisely characterizing this parameter includes finding the reliable uncer-tainty of the station velocity.In the article,we present a method to monitor veloci-ty uncertainties from GPS coordinates time series which are corrupted by tempo-rally correlated noise.A power-law noise plus white noise model is used in the research to prevent underestimation of the uncertainties and is parameterized in terms of orthonormal wavelet bases.Then the unknown parameters of the noise model can be iteratively estimated by the expectation-maximization algorithm and can be applied in Kalman filter.Nevertheless,different from white noise and ran-dom walk noise which can be characterized by an integer-ordered transfer func-tion,the power-law noise in the GPS coordinates time series is mathematically de-scribed by fractional-order calculus,which means that it is impossible to find a fi-nite integer-ordered filter to fit its straight line spectrum for all frequencies.As a consequence,an Oustaloup”s filter based numerical algorithm is developed to build a feasible state-space model describing such power-law noise.By applying the proposed state-space model in the Kalman filter,it is possible to estimate the velocity uncertainties in the real-time and the viability of the algorithm is verified by the results from simulations and the data of IGS station WTZR.
Power-law noise GPS time series Wavelets Kalman filter
Qingchen Zhang Bingbing Duan Urs Hugentobler
Technische Universit(a)t München,Arcisstra(b)e 21,80333 München
国内会议
哈尔滨
英文
1-14
2018-05-23（万方平台首次上网日期，不代表论文的发表时间）