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  • About
    8 January 2020, by Médéric Gravelle

    The GNSS solution named ’NGL14’ is produced by the Nevada Geodetic Laboratory (NGL) using a Precise Point Positioning (PPP) data analysis strategy. The GipsyX software (version 1.0) from the Jet Propulsion Laboratory (JPL) is employed to produce daily position time series for over 17,000 globally distributed stations using JPL satellite orbits and clock products expressed in the IGS14 reference frame (Blewitt et al. 2018). The data set covers the period January 1996 to March 2022.
    This (…)

  • 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
    17 January 2020, by Médéric Gravelle

    The GNSS solution named ’JPL14’ is produced by the Jet Propulsion Laboratory (JPL) group using a Precise Point Positioning (PPP) data analysis strategy. JPL’s GipsyX software is employed to produce daily position time series for over 2,000 globally distributed stations using JPL satellite orbits and clock products expressed in the IGS14 reference frame. The data set covers the period January 1994 to April 2022. This GNSS data analysis strategy complies with the standards (models, (…)

  • 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 (…)

  • 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 (…)

  • 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 (…)

  • Data access
    14 February 2008, by Guy Woppelmann

    The GPS observations are published on the anonymous FTP server of SONEL (ftp.sonel.org). The conditions of access are that the origin of the data is acknowledged in all communications, oral or written. Further details.
    The FileZilla tool is a free client ftp which allows you to access the data.

  • Role of SONEL
    27 October 2011, by Guy Woppelmann

    In addition to its national scope with its specific aims associated with a national research observation infrastructure on sea level, SONEL plays the role of GNSS at tide gauge data assembly centre for the GLOSS programme since 2011 (see GLOSS Implementation Plan - 2012, pp. 23). SONEL is also the primary data centre for the GPS Tide Gauge Benchmark Monitoring (TIGA) pilot project, which has turned into a working group of the International GNSS Service (IGS) in 2010.
    Consequently, SONEL (…)

  • Rôle de SONEL
    29 octobre 2011, par Guy Woppelmann

    Outre la dimension nationale de SONEL avec des objectifs particuliers propres à un dispositif national d’infrastructure d’observatoire de recherche du niveau de la mer, SONEL joue le rôle de centre de données GNSS (GPS) aux marégraphes pour le programme mondial GLOSS depuis 2011 (voir GLOSS Implementation Plan - 2012, pp. 23). SONEL est aussi le centre de données principal du projet pilote TIGA (GPS Tide Gauge Benchmark Monitoring Pilot Project), qui est devenu un groupe de travail (…)