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Jason 1



Jason 1 is an American-French (NASA-CNES) oceanographic satellite that was launched by a Delta 2 rocket from Vandenberg AFB 15:07 UT on 7 December 2001. It is intended to supplement and extend the TOPEX-Poseidon mission results by monitoring the sea surface level and wave heights. The 500 kg, 1.0 kW, triaxially stabilized spacecraft carries five instruments. The main observation/experiment is done by the altimeters; the four other instruments merely provide auxiliary data to correct and refine the altimeter data. There are two radars altimeters: the CNES Poseidon-2 Altimeter at 13.65 GHz and a NASA TOPEX Altimeter at 13.6 and 5.3 GHz, both measuring the sea surface with an accuracy of 4.2 cm. The NASA Jason Microwave Radiometer (JMR) enables water vapor measurement along the Altimeter path so as to correct the echo time. The CNES DORIS Doppler tracking antenna receives ground signals for precise determination of the satellite altitude after correction for ionospheric delays. The NASA BlackJack GPS receiver provides accurate location of the satellite. Finally, the NASA laser retroreflector array works with ground stations to track the satellite and calibrate/verify the Altimeter measurements. The data from Jason 1 will be made available through NASA/JPL and CNES. Data dump will be made over Poker Flats, Alaska, and Wallops Island, Virginia. For more details see

Alternate Names

  • 26997
  • EOS-ALT1
  • EOS-Altimetry
  • Jason1

Facts in Brief

Launch Date: 2001-12-07
Launch Vehicle: Delta II
Launch Site: Vandenberg AFB, United States


  • Earth Science

Additional Information

Questions and comments about this spacecraft can be directed to: Dr. Dieter K. Bilitza



NameRoleOriginal AffiliationE-mail
Mr. Lee-Lueng FuProject ScientistNASA Jet Propulsion
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