HR: 09:30h
AN: G41A-07    [Abstracts]
TI: Stability of VLBI, SLR, DORIS, and GPS positioning
AU: Feissel-Vernier, M
AF: Observatoire de Paris and LAREG/IGN, 61 rue de l'Observatoire, Paris, 75014, France
AU: * de Viron, O
EM: deviron@ipgp.jussieu.fr
AF: Institut de Physique du Globe de Paris and Université Paris 7, 4 Place Jussieu, Case 89, Paris, 75005, France
AU: Le Bail, K
EM: lebail@ensg.ign.fr
AF: LAREG/IGN, 6 - 8, Avenue Blaise Pascal Champs Sur Marne, Marne la Vallee, 77455, France
AB: The residual signal in VLBI, SLR, DORIS and GPS station motion, after a linear trend and seasonal components have been removed, is analysed to investigate site-specific and technique-specific error spectra. The study concentrates on 60 sites with dense observation history by two or more space geodetic techniques. The solutions analysed are single-analysis center solutions currently available. The GPS data are taken from the IGS files. Statistical methods include the Allan variance analysis and the three-cornered hat algorithm. The site-specific noise level is found to be in the range 0.5–3.5 mm in either horizontal direction and 1–4.5 mm in height for most sites. The distribution of site-specific noise type includes both white noise and flicker noise. White noise is predominant in the East direction. Both types of noise are found in the North direction, with no particular geographical clustering.Technique-specific noise characteristics are estimated in several ways, leading to a white noise diagnostic for VLBI and SLR in all three local directions. DORIS has also white noise in the horizontal directions, whereas GPS has a flicker noise spectrum. The vertical noise spectrum is indecisive for both DORIS and GPS. The three-dimensional noise levels for the one-year sampling time are 1.7 mm for VLBI, 2.5 mm for SLR, 5.2 mm for DORIS, and 4.1 mm for GPS. For GPS, the long-term analysis homogeneity has a strong influence. In the case of a test solution reanalysed in a fully consistent way, the noise level drops to the VLBI level in horizontal and to the SLR level in vertical. The three-dimensional noise level for a one-year sampling time decreases to 1.8 mm. In addition, the percentage of stations with flicker noise drops to only about 20% of the network.
DE: 1229 Reference systems
DE: 1241 Satellite geodesy: technical issues (6994, 7969)
DE: 1243 Space geodetic surveys
SC: Geodesy [G]
MN: 2007 Fall Meeting