Tytuł artykułu
Autorzy
Wybrane pełne teksty z tego czasopisma
Identyfikatory
Warianty tytułu
Konferencja
Final CERGOP-2/Environment Conference (13-14.07.2006; Graz, Austria)
Języki publikacji
Abstrakty
Within the Project our group has been responsible of WP6, which addresses the stability of time series of coordinates of GPS stations used in the project. In addition we have supported WP1, WP4, WP7 and WP10.1, as scheduled. The time series we have analysed result from WP1 and WP5. We have combined normal equations from the EUREF network, and selected those stations which are relevant to the CERGOP 2 project. Likewise for Italian and Austrian stations we have stacked normal equations pertaining the national networks, and obtained time series which are useful to the science part of the Project. Finally we have addressed the normai equations of the CEGRN campaigns, up to the CEGRN 03 campaign, constructed time series and checked for their continuity. An in depth analysis of the time series was done for those sites which have been active with continuity for at least three years. We did this analysis for all the stations which met this requisite, including time series of a number of stations computed by the Austrian partner OLG. The analysis consisted in the identification, in the time and frequency domains of specific signatures, typically annual and semi annual, affecting the time series and can be of various origin, such as seasonal water flow or thermal dilatation of the antenna mount. After removal of the periodic signals, the power spectral density has been computed and the white and coloured components in the noise could be characterized. We report in most cases flicker phase noise at low frequencies and white noise at higher frequencies (>2 cycles/year), with a few exceptions in which the noise is white at all frequencies. A few stability problems are reported. In particular our own ASIA station was affected by mount instability in connection to a heavy snow storm in February 2006. This event was promptly noticed from the analysis and the mount problem could be solved. We have checked for local instabilities by looking at deviations of the estimated velocities from the expected pattern. We have verified that the stations contributing to the project have velocities agreeing with theoretical predictions. When this does not happen, then the station in most cases has a marginal tracking his tory, and we suspect that the discrepancies are attributable to a weak data set, more than true instability. The contribution to the Project includes, besides the data analysis part, two new permanent stations which were installed in Asiago and Rovigo as part of the Project, and regularly operated. Two doctoral stipendia have been awarded, and a Web page dedicated to our WP6 has been constructed, regularly maintained and linked to the Project's web page.
Słowa kluczowe
Czasopismo
Rocznik
Tom
Strony
85--155
Opis fizyczny
wykr., tab., map., fot.
Twórcy
Bibliografia
Typ dokumentu
Bibliografia
Identyfikator YADDA
bwmeta1.element.baztech-article-PWA6-0030-0006
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