The Jason 1 satellite altimeter is a science project to measure the ocean surface topography, and the successor to the TOPEX/Poseidon satellite.

It is a joint project between the NASA (United States) and CNES (France) space agencies. It was launched on December 7, 2001 aboard a Boeing Delta II. Like TOPEX it has a 10 day repeat cycle.

The program is named after the greek mythological hero Jason.

It contains 5 instruments:

• Poseidon 2 - Nadir pointing Radar Altimeter using C band and Ku band for measuring height above sea surface.
• Jason Microwave Radiometer (JMR) - measures water vapor along altimeter path to correct for pulse delay
• DORIS (Doppler Orbitography and Radiopositioning Integrated by Satellite) for orbit determination to within 10 cm or less and ionospheric correction data for Poseidon 2.
• BlackJack Global Positioning System receiver provides precise orbit ephemeris data
• Laser retroreflector array works with ground stations to track the satellite and calibrate and verify altimeter measurements.

See also

• Argo, a project to measure the temperature and salinity of the upper 2 km of the water column.

External links

• Jason site at CNES
• TOPEX/Jason site at NASA