Mobile version

Altimetry measures close to the coasts of La Rochelle

Image of the Month - July 2025

Coastal altimetry is a complex topic - the radar beam can reflect on a mix of water and land, thus the data must be processed differently from the open ocean --. Moreover, the coastal dynamics involve tides, potentially extremely jagged coastlines. The "high-resolution" along-track data ("20 Hz") are needed to get as close as possible to the lands. Cnes/CTOH/Legos/CLS/Noveltis published a new dataset last year, AltiCap, with 20-Hz dedicated processed Sea Level Anomalies "close" to the coasts (less than 500 km), from Jason-3 only for now.

A study made in the frame of a PhD at La Rochelle Université (west of France, on the coasts of the Bay of Biscay) is looking at those data in their neighbourhood. The "pertuis charentais" is a shallow area between the coast around La Rochelle proper and the islands (Ré, Aix and Oléron islands) with complex currents and tides. A number of in situ stations are available there (La Pallice (La Rochelle) and  Aix Island tide gauges, GNSS station at Ré and Oléron Islands), some for a long time, which enable to validate the altimetry data. The study aims to extend the time series to other altimeters, on the "reference mission" historical track (Jason-1 & 2, Sentinel-6 Michael Freilich), but also others missions overflying the area (Sentinel-3A, Saral), and Swot nadir. 

See also:

References:

  • Vignudelli, S., Kostianoy, A. G., Cipollini, P., & Benveniste, J. (Eds.). (2011). Coastal altimetry. Springer Science & Business Media.
  • Léger, F., Birol, F., Bignalet-Cazalet, F., Cancet, M., Dagneaux, Q., Daguze, J. A., ... & Tolu, L. (2024, April). Towards an operational global coastal altimetry product: AltiCAP (ALTimetry Innovative Coastal Approach Product). In EGU General Assembly Conference Abstracts (p. 8206).
  • Birol, F., Fuller, N., Lyard, F., Cancet, M., Nino, F., Delebecque, C., ... & Léger, F. (2017). Coastal applications from nadir altimetry: Example of the X-TRACK regional products. Advances in Space Research, 59(4), 936-953.
EnglishFrançais
Rss feedsContactPartnersFAQLexiconLegal noticePersonal Data Protection PolicyMobile
You must enable cookies in your browser preferences to save the modifications
You are using an older version of Internet Explorer, please update to take full advantage of Aviso+ features

Customize the home page

View all widgets
Reduce display
Public profile
User profile

Select/Deselect widgets

Discover AVISO+

Customizable home, reading tools, products search guide, etc.. Discover step by step the features of the new site AVISO+.

Customizable homepage

This home page is composed of blocks called "widgets".

Rearrange the blocks with a "Click & Drop".

Hide a widget with the cross at the top right. Reset or add a widget with the "wrench" icon. The "User" and "Public" profiles offer a predefined organization.

All the modifications are automatically saved as cookies on your machine so as to enable you to have your own specific AVISO+.

Reading tools

Ease your reading by choosing the page background colour (black/white) and/or by modifying the font size.

Browsing menu and breadcrum trail

To ease your browsing through AVISO+, you can use at any time the main banner items with the interactive submenus or use the browsing menu on the left side of the screen (it is open by default). For more readiness of the page contents, you can fold and unfold the browsing menu by clicking on the tab. At any time you can know where you are thanks to the browsing menu or the breadcrum at the top of the page.

Products search guide

The first submenu of the "Data" banner item leads you to a new search form enabling you to find quickier the product that suits your needs. The list of results is updated according to your selection criteria.

AVISO+ Multimedia

The first submenu of the "Multimedia" banner item leads you to AVISO+ collections of images and videos linked to altimetry and its applications. Have a nice visit!