气候变化领域集成服务门户(CCPortal): Chameleonic Noise in GPS Position Time Series

CCPortal

DOI	10.1029/2020JB019541
	Chameleonic Noise in GPS Position Time Series
	Santamaría-Gómez A.; Ray J.
发表日期	2021
ISSN	21699313
卷号	126 期号:3
英文摘要	It has been a standard practice for about 2 decades to compute global positioning system (GPS)-based station velocity uncertainties using the apparent noise statistics of the non-linear position residuals rather than assume white noise (WN) behavior. The latter choice would yield unrealistic velocity uncertainties. The most common noise types used are power-law, usually close to flicker noise (FN), over most frequencies mixed with WN at the shortest periods. The complicating impact of offsets in the position time series, mostly caused by equipment changes or tectonic events, has not been fully appreciated. These are far less benign than recently suggested. In addition to contributing a pseudo-random walk noise (RW) component to the velocity errors, estimating offset parameters changes the apparent noise color toward whiter. Spectral power is effectively drained by offsets at periods longer than roughly the mean span between them. This consequently favors a Gauss-Markov process as the apparently preferred noise model and, importantly, obscures the presence of RW and long-period Earth deformation in the series. Both effects can lead to potentially under-estimated velocity uncertainties. The full value of decadal-long GPS time series for geodynamical applications is thereby greatly eroded by recurring offsets, especially when they occur quasi-regularly. In addition, contrary to common assumption, the noise color is generally not fixed with time, but clearly becomes whiter in more recent data. The origin of the colored noise and its whitening over time remain elusive. © 2021. American Geophysical Union. All Rights Reserved.
英文关键词	correlation; GPS; noise; offsets; uncertainty; velocity
语种	英语
来源期刊	Journal of Geophysical Research: Solid Earth
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/187273
作者单位	GET, Université de Toulouse, CNES, CNRS, IRD, UPS, Toulouse, France; National Geodetic Survey (retired), Silver Spring, MD, United States
推荐引用方式 GB/T 7714	Santamaría-Gómez A.,Ray J.. Chameleonic Noise in GPS Position Time Series[J],2021,126(3).
APA	Santamaría-Gómez A.,&Ray J..(2021).Chameleonic Noise in GPS Position Time Series.Journal of Geophysical Research: Solid Earth,126(3).
MLA	Santamaría-Gómez A.,et al."Chameleonic Noise in GPS Position Time Series".Journal of Geophysical Research: Solid Earth 126.3(2021).