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SWOT : a satellite to map the Earth’s water cycle

16 décembre 2022

The launch of the NASA SWOT satellite on Thursday, December 15, 2022 opens a new path for satellite altimetry and promises a complete coverage of surface waters (continental and oceanic). Within the Paris Observatory - PSL, SYRTE, through its involvement in the definition and realization of reference systems, and in particular the vertical reference that constitutes the mean sea level, is one of the pillars on which the SWOT mission is based.

The SWOT satellite was launched on December 15, 2022, into an orbit 891 km above sea level from Vandenberg AFB in the United States.

Vue artiste de SWOT
NASA/JPL-Caltech

SWOT (Surface Water Ocean Topography) is an Earth observation satellite responsible for measuring the level of surface waters - lakes, reservoirs and rivers -, their width and estimating through these variables the flow of major rivers, as well as determining in a very fine and accurate way the level of oceans and seas.

The project was developed between CNES, NASA, Thales Alenia and CNRS, with support from the UK and Canadian space agencies, and will last at least five years.

The satellite will screen the topography of 90 percent of the world’s water surfaces, a scale never before achieved.

Schéma du fonctionnement de l’interféromètre KaRIn embarqué sur SWOT
Cheinway Hwang, The Ohio State University

These measurements should lead to a better understanding of the water cycle and better control of water resources that have become critical, as well as refine our knowledge of ocean circulation to improve climate models.

For more information

Online seminar Altimetry - from metrology to climatology

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