Altimetry for the future: Building on 25 years of progress

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