Altimetry for the future: Building on 25 years of progress

International Altimetry Team, Saleh Abdalla, Abdolnabi Abdeh Kolahchi, Michaël Ablain, Susheel Adusumilli, Suchandra Aich Bhowmick, Eva Alou-Font, Laiba Amarouche, Ole Baltazar Andersen, Helena Antich, Lotfi Aouf, Brian Arbic, Thomas Armitage, Sabine Arnault, Camila Artana, Giuseppe Aulicino, Nadia Ayoub, Sergei Badulin, Steven Baker, Chris BanksLifeng Bao, Silvia Barbetta, Bàrbara Barceló-Llull, François Barlier, Sujit Basu, Peter Bauer-Gottwein, Matthias Becker, Brian Beckley, Nicole Bellefond, Tatyana Belonenko, Mounir Benkiran, Touati Benkouider, Ralf Bennartz, Jérôme Benveniste*, Nicolas Bercher, Muriel Berge-Nguyen, Joao Bettencourt, Fabien Blarel, Alejandro Blazquez, Denis Blumstein, Pascal Bonnefond, Franck Borde, Jérôme Bouffard, François Boy, Jean Paul Boy, Cédric Brachet, Pierre Brasseur, Alexander Braun, Luca Brocca, Inès Otosaka, Andrew Shepherd, Sammie Buzzard

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

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In 2018 we celebrated 25 years of development of radar altimetry, and the progress achieved by this methodology in the fields of global and coastal oceanography, hydrology, geodesy and cryospheric sciences. Many symbolic major events have celebrated these developments, e.g., in Venice, Italy, the 15th (2006) and 20th (2012) years of progress and more recently, in 2018, in Ponta Delgada, Portugal, 25 Years of Progress in Radar Altimetry. On this latter occasion it was decided to collect contributions of scientists, engineers and managers involved in the worldwide altimetry community to depict the state of altimetry and propose recommendations for the altimetry of the future. This paper summarizes contributions and recommendations that were collected and provides guidance for future mission design, research activities, and sustainable operational radar altimetry data exploitation. Recommendations provided are fundamental for optimizing further scientific and operational advances of oceanographic observations by altimetry, including requirements for spatial and temporal resolution of altimetric measurements, their accuracy and continuity. There are also new challenges and new openings mentioned in the paper that are particularly crucial for observations at higher latitudes, for coastal oceanography, for cryospheric studies and for hydrology. The paper starts with a general introduction followed by a section on Earth System Science including Ocean Dynamics, Sea Level, the Coastal Ocean, Hydrology, the Cryosphere and Polar Oceans and the “Green” Ocean, extending the frontier from biogeochemistry to marine ecology. Applications are described in a subsequent section, which covers Operational Oceanography, Weather, Hurricane Wave and Wind Forecasting, Climate projection. Instruments’ development and satellite missions’ evolutions are described in a fourth section. A fifth section covers the key observations that altimeters provide and their potential complements, from other Earth observation measurements to in situ data. Section 6 identifies the data and methods and provides some accuracy and resolution requirements for the wet tropospheric correction, the orbit and other geodetic requirements, the Mean Sea Surface, Geoid and Mean Dynamic Topography, Calibration and Validation, data accuracy, data access and handling (including the DUACS system). Section 7 brings a transversal view on scales, integration, artificial intelligence, and capacity building (education and training). Section 8 reviews the programmatic issues followed by a conclusion.

Original languageEnglish
Pages (from-to)319-363
Number of pages45
JournalAdvances in Space Research
Issue number2
Early online date23 Mar 2021
Publication statusPublished - 15 Jul 2021
Externally publishedYes

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