Surface Water and Ocean Topography Science Team (ROSES 2019)

Funding Agency:
National Aeronautics and Space Administration

Surface Water and Ocean Topography (SWOT) is a satellite mission being jointly developed by NASA and CNES (Centre National d'Etudes Spatiales), the French space agency, with contributions from the Canadian Space Agency (CSA) and the United Kingdom Space Agency (UKSA) and is currently scheduled for launch in 2021. Information on the SWOT mission and its capability to fulfill the objectives laid out for it can be found at the SWOT web site

SWOT mission will be NASA's first global survey of Earth's surface water to observe ocean surface topography, major lakes, rivers, and wetlands with unprecendented resolution. Technical and scientific challenges include reducing measurement noise by two orders of magnitude below that of conventional altimetry missions like Ocean TOPography EXperiment (TOPEX)/Poseidon and Jason series. The systematic measurement errors (e.g., baseline roll and metrology, water-vapor induced range errors, etc.) must also be reduced at oceanic mesoscales to more than one order of magnitude below the signal levels. Mesoscale tidal errors caused by coastal and internal tides must be corrected for. The effects of vegetation, target layover, and water mask accuracy over land are challenges to be met by the mission’s measurement system.

The SWOT mission will use Ka-band radar interferometry to produce a swath of elevation measurements collected over land surface waters and over the ocean water surface. These elevation measurements are necessary for studying changes in the amount of water stored and flowing through the world’s rivers, lakes, wetlands, reservoirs, etc. The measurements are fundamental for studying ocean surface topography and mesoscale and submesoscale processes in the ocean. On land, the SWOT mission will make the first high-resolution mapping of the height and area variations of water bodies such as lakes, reservoirs, and wetlands. SWOT will also provide measurements necessary for estimating river discharge. All of these elements are of key importance to monitoring and understanding the shifting freshwater resources. Over the ocean, the SWOT mission will extend the capability of existing nadir profiling altimeters to two-dimensional mapping at higher resolution enabling the study of energetic ocean currents, eddies, and fronts that contain most of the kinetic energy of the ocean. 


  • Notice of Intent: Oct. 17, 2019
  • Proposal: Nov. 21, 2019




Engineering and Physical Sciences
Environmental & Life Sciences

External Deadline

November 21, 2019