Surface Water and Ocean Topography

Surface Water and Ocean Topography
Rendering of the SWOT satellite
NamesSWOT
WATER HM
Mission typeHydrology / Oceanography
OperatorNASA / CNES
COSPAR ID2022-173A
SATCAT no.54754
Mission durationPlanned:
3 years
Elapsed:
2 years, 6 months and 4 days
Spacecraft properties
ManufacturerThales Alenia Space
Launch mass2,200 kg (4,900 lb)
Dimensions14.9 × 5 × 5 m (49 × 16 × 16 ft)
Power8,000 watts
Start of mission
Launch dateDecember 16, 2022, 11:46 UTC
RocketFalcon 9 Block 5 B1071-6
Launch siteVandenberg, SLC-4E
ContractorSpaceX
Orbital parameters
Reference systemGeocentric
RegimeLow Earth orbit
Periapsis altitude857 km (533 mi)
Apoapsis altitude857 km (533 mi)
Inclination77.6°
Period102.89 minutes
Repeat interval1 sidereal day

Alternate SWOT Mission Patch by NASA

The Surface Water and Ocean Topography (SWOT) mission is a satellite altimeter jointly developed and operated by NASA and CNES, the French space agency, in partnership with the Canadian Space Agency (CSA) and UK Space Agency (UKSA). The objectives of the mission are to make the first global survey of the Earth's surface water, to observe the fine details of the ocean surface topography, and to measure how terrestrial surface water bodies change over time.

While past satellite missions like the Jason series altimeters (TOPEX/Poseidon, Jason-1, Jason-2, Jason-3) have provided variation in river and lake water surface elevations at select locations, SWOT will provide the first truly global observations of changing water levels, stream slopes, and inundation extents in rivers, lakes, and floodplains. In the world's oceans, SWOT will observe ocean circulation at unprecedented scales of 15–25 km (9.3–15.5 mi), approximately an order of magnitude finer than current satellites. It does this using synthetic aperture radar interferometry. Because it uses wide-swath altimetry technology, SWOT will almost completely observe the world's oceans and freshwater bodies with repeated high-resolution elevation measurements, allowing observations of variations.