@article{fdi:010082143,
  title = {{A}ltimetry for the future : building on 25 years of progress},
  author = {{A}bdalla, {S}. and {K}olahchi, {A}. {A}. and {A}blain, {M}. and {A}rnault, {S}abine and {C}almant, {S}t{\'e}phane and {P}enhoat du, {Y}ves and {G}ourdeau, {L}ionel and {H}ernandez, {F}abrice and {M}arin, {F}r{\'e}d{\'e}ric and {L}evy, {M}arina and {N}ino, {F}ernando and {S}eyler, {F}r{\'e}d{\'e}rique and et al. and {I}nternational {A}ltimetry {T}eam},
  editor = {},
  language = {{ENG}},
  abstract = {{I}n 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. {M}any symbolic major events have celebrated these developments, e.g., in {V}enice, {I}taly, the 15th (2006) and 20th (2012) years of progress and more recently, in 2018, in {P}onta {D}elgada, {P}ortugal, 25 {Y}ears of {P}rogress in {R}adar {A}ltimetry. {O}n 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. {T}his paper summarizes contributions and recommendations that were collected and provides guidance for future mission design, research activities, and sustainable operational radar altimetry data exploitation. {R}ecommendations 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. {T}here 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. {T}he paper starts with a general introduction followed by a section on {E}arth {S}ystem {S}cience including {O}cean {D}ynamics, {S}ea {L}evel, the {C}oastal {O}cean, {H}ydrology, the {C}ryosphere and {P}olar {O}ceans and the "{G}reen" {O}cean, extending the frontier from biogeochemistry to marine ecology. {A}pplications are described in a subsequent section, which covers {O}perational {O}ceanography, {W}eather, {H}urricane {W}ave and {W}ind {F}orecasting, {C}limate projection. {I}nstruments' 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 {E}arth observation measurements to in situ data. {S}ection 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 {M}ean {S}ea {S}urface, {G}eoid and {M}ean {D}ynamic {T}opography, {C}alibration and {V}alidation, data accuracy, data access and handling (including the {DUACS} system). {S}ection 7 brings a transversal view on scales, integration, artificial intelligence, and capacity building (education and training). {S}ection 8 reviews the programmatic issues followed by a conclusion.},
  keywords = {{S}atellite altimetry ; {O}ceanography ; {S}ea level ; {C}oastal oceanography ; {C}ryospheric sciences ; {H}ydrology},
  booktitle = {25 years of progress in radar altimetry},
  journal = {{A}dvances in {S}pace {R}esearch},
  volume = {68},
  numero = {2 {N}o {S}p{\'e}cial},
  pages = {319--363},
  ISSN = {0273-1177},
  year = {2021},
  DOI = {10.1016/j.asr.2021.01.022},
  URL = {https://www.documentation.ird.fr/hor/fdi:010082143},
}