Recent GURN results
Preliminary check of the quality of the GNSS sites
Using TEQC (UNAVCO) code-related multipath effects as well as the percentages of missing data of each site are quantified. This enables a preliminary quality classification of the GURN sites.
Analyzing the L3 residual time series of phase observations WaSoft/Multipath (link: www.wasoft.de) detects – under several assumptions – multipath effects of observation sites in order to improve the code-based quality classification of the GURN sites.
Legend: dot = observations; no dot = no observations; small rectangles = few multipath effects; large rectangles = large multipath effects.
In contrast to the French sites, SAPOS® sites are equipped with absolute calibrated antennas. The effects of an alternative antenna modeling on the estimation results were analyzed.
Values of differential code biases (DCB) calculated using the PPP module of the Bernese GPS Software enables to discover problematic site equipments.
Case study: Monumentation GURN sites
The dense SAPOS® network was established to guarantee point positioning for cadastral applications with an accuracy of a few cm.
If these sites should be used for highly precise geodynamical applications (Faulhaber 2007) the monumentation has to be validated.
The GIK monitored several SAPOS® sites using additional sensors (e. g. tiltmeters). At the SAPOS® site Iffezheim (0388) a significant correlation bet-ween the behavior of the monument-based movement of the GNSS antenna and the external effect “filling level of the two ship locks” could be detected.
For further information see link (German language)
Preliminary time series
The GPS data were analyzed using the GAMIT/GLOBK 10.33 version at Strasbourg IPGS. These 3 figures present some of the longest time series of our GPS network: STJ9 is locating in the Rhine Graben at about 10 km of Strasbourg, France. WELS is located in the Vosges mountains. SJDV is another GPS station included in our processing SJDV is not located in the Upper Rhine Graben. Since 2007, the IGPS has installed 5 new continuous GPS stations (EOST, MAKS, LUCE, AUBU, BUAN) on the French side of URG or in the vicinity.
Using PPP modul of the Bernese GPS Software preliminary time series of all GURN sites were derived within the ITRF2005 (Altamimi et al. 2007), thus the Eurasian trend of the horizontal, local topocentric coordinates is clearly visible. Analyzing the time series (e. g. scattering) the quality classification could be improved