Home > Keywords > Articles spéciaux > onglet

onglet

Articles

  • The historical French heritage
    14 December 2010, by Frank

    France is very rich in systematic observations of coastal sea level over long time periods. The oldest (published) series of measurements were performed by the astronomers La Hire and Picard at Brest, France, in 1679, over about ten days. They repeated the experiment in 1692, over several months, again in Brest. Their aim was to study the tides and their results showed the fundamental importance of observation to understand and determine the characteristics of tides in a given place for the (…)

  • Le patrimoine historique
    28 mars 2008, par Guy Woppelmann

    La France est très riche en observations systématiques de hauteur d’eau le long des côtes sur de longues périodes de temps. Les plus anciennes séries de mesures (publiées) furent réalisées par les astronomes La Hire et Picard à Brest, en France, en 1679 pendant une dizaine de jours. Ils renouvelleront leur expérience en 1692, pendant plusieurs mois, toujours à Brest. Leur objectif : l’étude de la marée. Leurs résultats montreront l’intérêt fondamental de l’observation pour connaître et (…)

  • Description of the DORIS tracking beacons
    10 December 2010, by Frank

    The DORIS network of tracking beacons was established by IGN in 1986 and has been run and maintained by them since then. Geodetic files describe the stations of the DORIS network. They are avilable on the web site of IDS (International DORIS Service) on a page that also has a dynamic map showing the geographical distribution of the network (click on the link).

  • About
    22 February 2017, by Mikaël Guichard

    In briefest terms, the approach consists in differencing the sea level time series from a tide gauge with an equivalent time series from satellite altimetry. To the extent that both instruments measure identical ocean signals, their difference is a proxy for the vertical position of the tide gauge. Assuming that the instrumental drifts are negligible, the time series of the sea level differences will then be dominated by vertical land motion at the tide gauge. This is illustrated in the (…)

  • What GNSS data?
    10 December 2010, by Guy Woppelmann

    The GNSS observations that we provide are in the form of daily 30s files (24h of observations at 30s intervals) in the standard international RINEX format. Further information on the RINEX files.
    Apart from the RINEX observation files of the GNSS stations, SONEL provides ancillary information which enables a precise analysis of the GNSS measurements, in particular :
    – the precise orbits of IGS,
    – the Earth orientation parameters of IGS. Evolution of the number of Rinex files (…)

  • Download
    17 January 2020, by Médéric Gravelle

    – Vertical velocities table
    The JPL14_Vertical-Velocities_Table provides the vertical GPS velocities and uncertainties from the 436 stations fulfilling the criteria of 3 years of minimum length and data gaps not exceeding 30%, estimated by the JPL group.
    – Daily time series
    The JPL14.zip file contains individual station data files of daily position time series in ITRF2014 with respect to the position at the epoch 2023-01-01. These positions are expressed in meters in the local frame (…)

  • Téléchargements
    28 août 2020, par Médéric Gravelle

    – Table des vitesses veticales
    La tabel GT2_Vertical-Velocities_Table contient les vitesses verticales et les incertitudes associées, calculées par l’équipe du GFZ, des 593 stations satisfaisant les critères de 3 ans minimum de longueur sans discontinuités, avec des "trous" n’excédant pas les 30%.
    – Séries temporelles journalières
    Le fichier GT2_neu.zip contient les séries temporelles individuelles dans l’ITRF2014 par rapport à l aposition à l’époque de référence. Les positions sont (…)

  • Statistics
    4 March 2020, by Médéric Gravelle

    General Analysis center: ULR Number of stations: 674 Solution: ULR6B CGPS@TG 482 Date of publication: 2020 Reference Frame 194 Time span: 1995.0 - 2013.9 Others 77 Reference Frame: ITRF 2014
    Vertical velocity field Estimated (robust) velocities: 493 CGPS@TG 349 Average of formal errors: 0.54 mm/yr Median of formal errors: 0.36 mm/yr

  • DOI ULR-repro3 solution
    27 May 2022, by Médéric Gravelle

    – General information Access the data by clicking on the Download tab
    Title: GPS Solution ULR7a DOI identifier: 10.26166/sonel_ulr7a Publisher: SONEL Data Assembly Centre Publication year: 2022 Version: a Temporal coverage: 2000-01-01 / 2020-12-31 Tile: The ULR-repro3 GPS data reanalysis solution (aka ULR7a) Language: English Authors
    Médéric Gravelle [1], Kevin Gobron [2], Guy Wöppelmann [1] Affiliation: [1]: UMR 7266 LIENSs, CNRS/LRU, La Rochelle, (…)

  • How to access the tide gauge observations
    20 February 2011, by Guy Woppelmann

    The files of average values
    Only the daily, monthly and annual averages calculated from quality controlled (QC’ed) data are provided in the data files. However, the graphs show the averages calculated from QC’ed observations (in blue) and non-QC’ed observations (in red). The averages are calculated from the Demerliac filter and the Doodson filter, with the possibility of a choice for the user. An example is given on the image below, which is taken from the web page of the La Rochelle (…)