Impact of Estimating Position Offsets on the Uncertainties of GNSS Site Velocity Estimates
We study the impact of estimating offsets within GNSS position time series on the uncertainties of site velocity estimates. Site velocity uncertainties are estimated by assuming different observational noise types, including white noise, fractal white noise, flicker noise, first-order Gauss-Markov n...
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| Format: | Article |
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American Geophysical Union (AGU)
2020
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| Online Access: | https://hdl.handle.net/1721.1/125826 |
| _version_ | 1826204687816196096 |
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| author | Wang, Lei Herring, Thomas A |
| author2 | Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences |
| author_facet | Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences Wang, Lei Herring, Thomas A |
| author_sort | Wang, Lei |
| collection | MIT |
| description | We study the impact of estimating offsets within GNSS position time series on the uncertainties of site velocity estimates. Site velocity uncertainties are estimated by assuming different observational noise types, including white noise, fractal white noise, flicker noise, first-order Gauss-Markov noise, random walk, fractal random walk, and mixture of flicker noise, and white noise. For each noise type, we assess the sensitivity of the velocity uncertainty to offsets numerically by computing the inflation rate of the uncertainty as the number of offset parameters increases.We show that the sensitivity reduces when the noise becomes more temporally correlated. For the mixture of flicker noise plus white noise, which has been concluded as an appropriate noise model for the majority of current GNSS position time series, the rate uncertainty increases by about 11% as the number of offset parameters doubles from 1 to 2 provided that the white noise does not dominate the flicker noise. Based on the analysis
of the Plate Boundary Observatory position time series, we find that adding one additional offset parameter would increase the median velocity standard deviation by 14%, consistent with the result of the simulation study. Such increase is much smaller than the conclusion of a 40% by a previous study. Therefore, given the noise characteristics of current GNSS site position estimates, position offsets have limited impact on uncertainties of site velocity estimates. This result implies that improving instrumentation, even though may introduce position offsets, is the best approach for improving reference frame stability. |
| first_indexed | 2024-09-23T12:59:30Z |
| format | Article |
| id | mit-1721.1/125826 |
| institution | Massachusetts Institute of Technology |
| last_indexed | 2024-09-23T12:59:30Z |
| publishDate | 2020 |
| publisher | American Geophysical Union (AGU) |
| record_format | dspace |
| spelling | mit-1721.1/1258262022-09-28T11:20:52Z Impact of Estimating Position Offsets on the Uncertainties of GNSS Site Velocity Estimates Wang, Lei Herring, Thomas A Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences We study the impact of estimating offsets within GNSS position time series on the uncertainties of site velocity estimates. Site velocity uncertainties are estimated by assuming different observational noise types, including white noise, fractal white noise, flicker noise, first-order Gauss-Markov noise, random walk, fractal random walk, and mixture of flicker noise, and white noise. For each noise type, we assess the sensitivity of the velocity uncertainty to offsets numerically by computing the inflation rate of the uncertainty as the number of offset parameters increases.We show that the sensitivity reduces when the noise becomes more temporally correlated. For the mixture of flicker noise plus white noise, which has been concluded as an appropriate noise model for the majority of current GNSS position time series, the rate uncertainty increases by about 11% as the number of offset parameters doubles from 1 to 2 provided that the white noise does not dominate the flicker noise. Based on the analysis of the Plate Boundary Observatory position time series, we find that adding one additional offset parameter would increase the median velocity standard deviation by 14%, consistent with the result of the simulation study. Such increase is much smaller than the conclusion of a 40% by a previous study. Therefore, given the noise characteristics of current GNSS site position estimates, position offsets have limited impact on uncertainties of site velocity estimates. This result implies that improving instrumentation, even though may introduce position offsets, is the best approach for improving reference frame stability. NASA NIP (Grant 80NSSC18K0748) NASA ESI (Grant 80NSSC18K0457) 2020-06-16T20:28:02Z 2020-06-16T20:28:02Z 2019-12 2019-03 Article http://purl.org/eprint/type/JournalArticle 2169-9313 2169-9356 https://hdl.handle.net/1721.1/125826 Wang, Lei and Thomas Herring. "Impact of Estimating Position Offsets on the Uncertainties of GNSS Site Velocity Estimates." Journal of Geophysical Research: Solid Earth 124, 12 (December 2019): 13452-13467 © 2019 American Geophysical Union http://dx.doi.org/10.1029/2019jb017705 Journal of Geophysical Research: Solid Earth Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. application/pdf American Geophysical Union (AGU) Prof. Herring |
| spellingShingle | Wang, Lei Herring, Thomas A Impact of Estimating Position Offsets on the Uncertainties of GNSS Site Velocity Estimates |
| title | Impact of Estimating Position Offsets on the Uncertainties of GNSS Site Velocity Estimates |
| title_full | Impact of Estimating Position Offsets on the Uncertainties of GNSS Site Velocity Estimates |
| title_fullStr | Impact of Estimating Position Offsets on the Uncertainties of GNSS Site Velocity Estimates |
| title_full_unstemmed | Impact of Estimating Position Offsets on the Uncertainties of GNSS Site Velocity Estimates |
| title_short | Impact of Estimating Position Offsets on the Uncertainties of GNSS Site Velocity Estimates |
| title_sort | impact of estimating position offsets on the uncertainties of gnss site velocity estimates |
| url | https://hdl.handle.net/1721.1/125826 |
| work_keys_str_mv | AT wanglei impactofestimatingpositionoffsetsontheuncertaintiesofgnsssitevelocityestimates AT herringthomasa impactofestimatingpositionoffsetsontheuncertaintiesofgnsssitevelocityestimates |