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  • About
    27 May 2022, by Médéric Gravelle

    The ULR7a GPS solution is a preliminary version of the reanalysis of 21 years of GPS data from 2000 to 2020 that has been undertaken within the framework of the 3rd data reprocessing campaign of the International GNSS Service (IGS). Its associated vertical velocity field is expressed in ITRF2014.
    Double-differenced ionosphere-free GPS carrier phase observations from daily regional (plus one global) networks of 546 stations were reanalyzed using a free-network strategy (station positions, (…)

  • About
    13 September 2013, by Mikaël Guichard

    – Relative sea level trends: The relative sea level trends have been estimated by the PSMSL from the RLR tide gauge dataset of annual times series longer than 30 years with more than 70% of valid data. Only results from tide gauges for which a robust GPS velocity is available are displayed. (More about the PSMSL relative sea level trends). Absolute sea level trends: The absolute (geocentric) sea level trends build upon the above-mentioned relative sea level trends by simply adding the (…)

  • 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 (…)

  • Fournisseurs GNSS
    6 janvier 2017, par Mikaël Guichard
  • About
    25 August 2020, by Médéric Gravelle

    The GNSS solution named ’GT2’ is produced by the German Research Centre for Geosciences (GFZ) for the International GNSS Service (IGS) working group TIGA. It contains position time series for 757 permanent GNSS stations expressed in the ITRF2014 reference frame over the period January 1994 to December 2015. This GNSS solution was carried out within the framework of the 2nd IGS reanalysis (reprocessing) campaign (Repro2). Among the 757 stations processed by GFZ, as many as 538 have (…)

  • About
    21 October 2022, by Médéric Gravelle

    The GNSS solution named ’GT3’ is produced by the German Research Centre for Geosciences (GFZ) for the International GNSS Service (IGS) working group TIGA. It contains position time series for 319 permanent GNSS stations expressed in the ITRF2014 reference frame over the period January 1994 to December 2020. This GNSS solution was carried out within the framework of the 3rd IGS reanalysis (reprocessing) campaign (Repro3). Among the 319 stations processed by GFZ, as many as 272 have (…)

  • Téléchargements
    27 janvier 2020, par Médéric Gravelle

    – Table des vitesses verticales
    La table NGL14_Vertical-Velocities_Table contient les vitesses verticales GPS estimées par le groupe NGL en utilisant MIDAS, pour les 1069 stations satisfaisant les critères de 3 ans minimum de longueur avec des "trous" n’excédant pas les 30%.
    – Séries temporelles journalières
    Le fichier NGL14.zip contient les séries temporelles individuelles de positions des stations exprimées dans l’ITRF2014, calculées par le groupe NGL, par rapport à la position à (…)

  • About
    4 March 2020, by Médéric Gravelle

    The ULR6b GPS solution is an updated version of ULR6a. That is, ULR6b is aligned in the ITRF2014 reference frame, instead of ITRF2008 for ULR6a. Both UMR6 solutions result from the reanalysis of 19 years of GPS data from 1995 to 2014, carried out within the framework of the 2nd reanalysis (reprocessing) campaign (repro2) of the International GNSS Service (IGS).
    Double-differenced ionosphere-free GPS carrier phase observations from a global network of 756 stations were reanalyzed using (…)

  • 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 (…)