Jason-1 is successor to the TOPEX/POSEIDON mission which is designed to ensure the continuity of TOPEX/POSEIDON-class measurements. (Launched: December 2001)

 

GSFC/WFF (Goddard Space Flight Center's Wallops Flight Facility - NASA) was responsible for specifying and providing the dual-frequency altimeter which is the prime instrument for the TOPEX/POSEIDON mission.

 

AVISO/Altimetry is the French Active Archive Data Center for multi-satellite altimeter missions responsible for post-processing, analyzing, archiving and distributing altimetry data for CNES (Centre National d'Etudes Spatiales), the French Space Agency.

 

UTCSR (University of Texas - Center for Space Research) provides access to dynamic ocean topography data sets observed by the TOPEX/POSEIDON altimeters as well as 10-day maps of sea level variability about the mean topography (1992-Present). 

 

Seasat was the first JPL mission to study Earth using imaging radar; specifically designed to observe the ocean. (Launched: 1978)

 

Geosat (GEOdetic SATellite) was a dedicated US Navy military oceanographic satellite designed to obtain closely spaced, precise mapping of the earth's geoid over the ocean. (Launched: 1985)

 

ERS-1 and ERS-2 are European Space Agency (ESA) satellites devoted to remote sensing. (Launched: 1991 and 1995, respectively)

 

GFO (GEOSAT Follow-On) site maintained by the NOAA Laboratory for Satellite Altimetry. The GFO program is the Navy's initiative to develop an operational series of radar altimeter satellites to maintain continuous ocean observation from the GEOSAT Exact Repeat Orbit. (Launched: 1998)

 

ENVISAT (ENVIronment SATellite) will be ESA's third major remote sensing effort. It will be primarily a research-oriented mission, carrying essentially pre-operational instruments for monitoring and studying the Earth's environment. (Launched: March 2002)

 

WITTEX (Water Inclination Topography and Technology Experiment) consists of three co-planar small-satellite radar altimeters shown in the above figure. The satellites are spaced apart by several hundred kilometers along their orbit. Earth rotation causes their sub-satellite tracks to be laterally separated. The measurements along each set of three near-parallel tracks occur within minutes of each other, so that the cross-track surface gradient can be measured as well as the usual along-track gradient. Hence, two orthogonal components of the surface gradient can be observed, from which can be derived the two-dimensional geostrophic current.