Themes & Objectives:

Radar altimetry is a key component of the Global Earth Observation System of Systems (GEOSS), and over the last 30 years has provided the principal global data source enabling the advancement of Earth System Science and the development of operational oceanography & hydrology. Radar altimetry contributes to a large number of societal needs, from climate monitoring to weather forecasting, with subsequent applications in a range of activities of socio-economic importance, including agriculture, health, energy, the freshwater resource, maritime safety, etc. Contributors to the Symposium are invited to submit abstract describing the evolution of their work and results in the past five years working on the 30 years of available multi-mission altimetry data.


The symposium will be organized around key papers, presenting the challenges we have overcome to develop our current understanding of the Earth’s surface variations observed by altimetry, and the perspectives for future developments in each of the following themes:

1) 30 Years of Progress in Radar Altimetry: a historical perspective (keynote presentations)

  • Historical review 
  • Lessons learned in the last five years
  • Improvements thanks to SAR, Ka and Swath altimetry
  • Successful and unachievable projects, unexpected applications in:

  • Global Ocean,
  • Coastal Zone,
  • Polar Ocean
  • Land and Inland Water,
  • Cryosphere

2) Advances in our understanding of the dynamic ocean

  • Ocean currents: how have things improved in 30 years? 
  • Large scale ocean phenomena: intra-seasonal, seasonal cycle, El Nino, Rossby waves, pluri-annual oscillations 
  • Tide modeling, non-linear components, internal waves 
  • High frequency signals and mesoscale
  • Marine meteorology, wave height and wind speed 
  • Detecting rain, air-sea exchange fluxes

3) Advances in our understanding of coastal processes

  • Coastal retracking
  • Coastal corrections
  • Integration of multi-mission coastal products
  • Modeling coastal processes
  • Data assimilation in coastal/regional models
  • Societal impacts (e.g., erosion, storm surges...)

4) Advances in our understanding of the polar ocean

  • Ocean dynamics and Sea-ice monitoring, sea-ice thickness, sea-ice extent
  • Iceberg tracking
  • Impact of polar ocean to Mean Sea Level
  • Retracking, specific corrections and processing methods in those complex zones (tides, MSS, ...)
  • Integration of multi-mission products
  • Modeling processes
  • Data assimilation 

5) Altimetric contributions to gravity field, marine geoid, bathymetry modeling and orbit determination

  • The impact of long repeat mission, further improvements, and expectations 
  • Ocean floor topography mapping 
  • Orbit determination and gravity model tailoring: contributions of DORIS 
  • DORIS, GPS, laser techniques and altimetry 
  • Gravimetry results from geodetic missions (including CHAMP, GRACE, GOCE, SWARM and preparation for MAGIC/NGGM) 
  • Improved mean sea surfaces (contributions from geodetic missions)

6) Altimetry over Land and Inland Water

  • Specialised data processing for inland water applications
  • River level and river discharge and land-ocean exchange (with focus on estuaries)
  • Lake level and volume variation monitoring
  • Wetlands
  • Synergy of altimetry with other remote sensing data
  • Hydraulic and hydrologic modelling and data assimilation  
  • Global digital elevation models (and continuity with tidal flats and coastal bathymetry)
  • Land processes, surface roughness and soil moisture

7) Advances in our understanding of the Cryosphere

  • Antarctic and Greenland topography, volume and mass balance
  • Continental glaciers 
  • (The polar ocean is in theme 4)

8) Building the 30-year altimetric record: challenges and achievements

  • (Cross-)Calibration and long-term monitoring of instruments: biases, drift models, shortcomings, improvements
  • Validation of long time-series with in situ data
  • From LRM to SAR altimetry: how to insure a seamless transition
  • Global and regional multi-satellite sea level change: the spatial and temporal record
  • Advances in precision: from 15 cm to the millimeter (and sub mm/yr) challenge! 
  • Interesting/unexpected scientific results: absolute dynamic topography, global and regional mean sea level trends, lake and river discharge trends, ice volume trends, interannual changes in eddy processes, decadal oscillations... 

9) Synergy between Altimetry, other data and models: "The integrated approach"

  • Comparison with in situ data: tide gauges, ship data, buoys, Argo profilers and HF radar ... 
  • Synergy with variable gravity (GRACE, GRACE-FO, MAGIC/NGGM), thermosteric (Argo) and Altimetry.
  • Synergy of sea level, sea surface temperature, ocean colour, sea surface salinity and wind stress
  • Synergistic studies of the interaction of ocean circulation with ocean biology and air-sea coupling processes
  • Altimetry impact in ocean monitoring and operational forecasting systems 
  • Operational hydrology

10) Outreach

  • Education programmes 
  • Science returns towards the public 
  • The use of the internet and social media to promote satellite altimetry
  • Open and citizen science
  • Toolboxes and open access databases

11) Outlook: the next generation altimetry

  • Requirements for future Altimetric missions (Oceanography, Coastal Zone, Inland Water, Land, Cryosphere) 
  • Operational oceanography and hydrology missions, continuity and services
  • Third generation altimeters (synthetic aperture and wide swath instruments) 

12) The International DORIS Service (IDS) : new challenges 

  • DORIS network and constellation: status and evolution
  • IDS processing and Terrestrial Reference Frame
  • Precise Orbit Determination and advances in dynamic force and observable modelling
  • Research activities and new applications using DORIS data, or new methods of processing DORIS data

13) S3 - S6 VT and OSTST Technical Presentations

  • Plans for (mostly) common evolutions of the processors and products, and overview of data distribution (presentations to be given by EUM, PO.DAAC and ESA).
  • Review of Cal/Val activities, lessons learned, future mission plans.
  • Contributions to the Cal/Val of Sentinel-3 and -6: current status, new developments, wishes, recommendations.
  • The latest in Instrument Processing (Altimeter SAR and Radiometer).
  • Any typical subject of traditional OSTST splinters