onglet

Articles

• Programme GLOSS
  21 août 2017, par Guy Woppelmann

  The Global Sea Level Observing System (GLOSS) was established by the UNESCO Intergovernmental Oceanographic Commission (IOC) in 1985 to establish a well-designed, high-quality in situ sea level observing network to support a broad research and operational user base.
  GLOSS provides oversight and coordination for global and regional sea level networks that supports the oceanographic and climate research communities based on feedback and direction from within these communities. GLOSS remains (…)

• Download
  14 October 2025, by Médéric Gravelle

  – Vertical velocities table
  The ULR20_Vertical-Velocities_Table provides the vertical GNSS velocities and uncertainties for the 1011 stations fulfilling the criteria of 3 years of minimum length without discontinuities and with data gaps not exceeding 30%.
  The velocities come from the adjustment of both a functionnal and stochastic model, the latter accounting for a linear combination of white noise and power law process, whose parameters were estimated using the PyTRF python library (P. (…)

• GNSS Data Providers
  9 January 2017, by eprout01
• Accès aux données
  11 décembre 2010, par Mikaël Guichard

  Les observations GPS sont accessibles sur le serveur FTP de SONEL (ftp.sonel.org) de manière anonyme. Les conditions d’accès sont de citer la source des données dans toute communication, orale ou écrite. Plus de détails.
  L’outil FileZilla est un client FTP gratuit qui permet d’accéder facilement aux données.

• Comment accéder aux observations des marégraphes ?
  20 février 2011, par Mikaël Guichard

  Les fichiers de valeurs moyennes
  Seules les moyennes calculées à partir des données contrôlées sont fournies dans les fichiers de valeurs. Dans les graphiques, en revanche, sont représentées les moyennes calculées à partir des observations contrôlées (en bleu) et non-contrôlées (en rouge). Les moyennes sont calculées à partir du filtre de Demerliac et du filtre de Doodson, avec possibilité de choix pour l’utilisateur. Un exemple est donné dans l’image ci-dessous, prise de la page de la (…)

• Calibration measurements
  10 December 2010, by Frank

  These are measurements of the water level which are carried out simultaneously with a tide gauge and an instrument that is used as a standard, often an electric sound/light sensor. When the measurements are performed over a complete tide cycle (12h25), they can be used to produce a Van de Casteele diagram. The shape of this diagram is highly instructive; it can be used to assess the performances of the tide gauge and to detect any operational defects. This type of test is recommended by (…)

• Statistics
  27 May 2022, by Médéric Gravelle

  Vertical velocity field Estimated (robust) velocities: 546 CGPS@TG 461 Average of formal errors: 0.38 mm/yr Median of formal errors: 0.28 mm/yr

• 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 (…)

• Which observations ?
  16 February 2011, by Frank

  The tide gauge observations are heights of sea level expressed with respect to an arbitrary (conventional) and local datum. Hence, the term relative sea level is often used (relative to the land upon which the tide gauge is grounded).
  The sea level data available on SONEL are: daily mean sea levels obtained from different tidal filters (e.g., Doodson, Demerliac); monthly and annual mean sea levels, which contribute to the world data bank of the PSMSL.
  Other kinds of water levels are (…)