HR: 0800h
AN: G11A-1201    [Abstracts]
TI: Application of wavelets for secular vertical land movement determination in the Netherlands from permanent GPS observations
AU: Hanssen, R
EM: R.F.Hanssen@LR.TUDelft.NL
AF: DEOS, Faculty of Aerospace Engineering, Delft University of Technology, Kluyverweg 1, Delft, 2629 HS Netherlands
AU: * Grebenitcharsky, R
EM: R.Grebenitcharsky@LR.TUDelft.NL
AF: DEOS, Faculty of Aerospace Engineering, Delft University of Technology, Kluyverweg 1, Delft, 2629 HS Netherlands
AU: Ditmar, P
EM: P.Ditmar@LR.TUDelft.NL
AF: DEOS, Faculty of Aerospace Engineering, Delft University of Technology, Kluyverweg 1, Delft, 2629 HS Netherlands
AB: Weekly EUREF solutions can be used to form time series for the vertical component of permanent GPS observations. The derivation of secular vertical land movements from those time series requires the elimination of possible spurious jumps and periodical components. Wavelets can be used for this purpose because they have good localization properties both in the time and in the spectral domain. On different levels of decomposition jumps and periodical components can be detected and removed. In particular, jumps in the data can be detected because wavelet transforms are considered as n-th multilevel differential operators if they have n-1 vanishing moments. In this case proper wavelet types can help to identify and remove jumps in the data. Also, periodical movements with different periods can be detected and removed at every decomposition step. After removing all these components, the reconstructed signal contains only long wavelengths present in the signal and can therefore be used for the secular vertical velocity determination. Time series of EUREF stations in the territory of the Netherlands are used to investigate the efficiency of the proposed technique. The derived estimates for the vertical rates are compared with results from the direct least-squares adjustment of the GPS time series and with the leveling data acquired in the course of the last century. Conclusions about the applicability of wavelets for the secular vertical velocity determination are drawn.
DE: 1211 Non-tectonic deformation
SC: Geodesy [G]
MN: Fall Meeting 2005