Abstract's details

The new generation of high-resolution X-TRACK/ALES regional altimetry product

Fabien LEGER (LEGOS / CTOH, France)


Florence Birol (LEGOS / CTOH, France); Fernando Niño (LEGOS / CTOH, France); Marcello Passaro (DGFI-TUM, Germany); Christian Schwatke (DGFI-TUM, Germany)

Event: 2019 Ocean Surface Topography Science Team Meeting

Session: Coastal Altimetry

Presentation type: Type Poster

Contribution: not provided


Sea level variation is one of the major threats for coastal zones; its observation is essential to better understand and predict the behavior of the coastal ocean. Altimetry provides unique long term and almost global observational dataset to characterize how sea level variability evolves from the open ocean to the coastal ocean.

More than 10 years ago, the CTOH and LEGOS started to develop the X-TRACK processing chain in order to recover as more as possible coastal sea level observations from the GDR altimetry products. Now, X-TRACK is a mature multi-mission along-track altimetry 1-Hz product and as well a along-track empirical tidal constants product, covering all the coastal ocean, produced by the CTOH/LEGOS and freely distributed by the operational AVISO+ service.

The new version of the processing chain we present, integrates progress made by the altimetry community in the last years, both in terms of the retracker and the geophysical corrections applied. The ALES retracker has proven its efficiency in retrieving more coastal sea level observations than other retrackers, particularly when using high-rate (i.e. 20 Hz) altimeter measurements instead of the standard (1 Hz) data. On the other hand, geophysical corrections wet tropospheric and tidal corrections in particular, have also improved in the coastal domain. In the context of the bridging phase of the ESA’s climate change initiative sea-level project (SL_cci) and acknowledging user needs, we develop a new X-TRACK L3 multi-mission product combining the better spatial resolution provided by high-rate data (20-Hz), the post-processing strategy of X-TRACK and the advantage of the ALES retracker. This product increases the number of useful near shore sea level data available and provides then new informations that opens new fields of applications.

Poster show times:

Room Start Date End Date
The Gallery Tue, Oct 22 2019,16:15 Tue, Oct 22 2019,18:00
The Gallery Thu, Oct 24 2019,14:00 Thu, Oct 24 2019,15:45
Fabien LEGER