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There is also a PDF version of the Fact Sheet.

Objectives

- Extend ocean surface topography into the 21st century
- Provide a 5-year view of global ocean surface topography
- Increase understanding of ocean circulation and seasonal changes
- Improve forecasting of climate events like El Niño
- Measure global sea-level change
- Improve open ocean tide models
- Provide estimates of significant wave height and wind speeds over the ocean

Mission

- Joint NASA-CNES program
- Launched: December 7, 2001
- Launch Vehicle: Boeing Delta II 7920; shared with NASA TIMED mission, with Jason-1 separating first
- Launch Site: Vandenberg AFB, California
- Operations for 5-year prime mission: JPL
- Orbit: 1336 km, circular, 66° inclination
- 10-day repeat of ground track (±1-km accuracy)
- Covers 95% of ice-free oceans every 10-days

Spacecraft

- Based on Alcatel's Proteus bus
- Total mass: 500 kg (1102 lbs)
- Twin solar panels provide 1.0 kW of power
- Satellite communicates through the Wallops Ground Network Tracking Stations at Poker Flats, Alaska and Wallops Island, Virginia
- Reaction wheels and magnetic torque rods maintain 3-axis stabilization and nadir-pointing
- Hydrazine propellant system provides orbital maintenance

Payload/Sensors

- CNES Poseidon-2 Altimeter (C- and Ku-band) measures height above sea surface
- NASA Jason Microwave Radiometer (JMR) measures water vapor along altimeter path to correct for pulse delay
- CNES DORIS Doppler tracking antenna receives ground signals for precise orbit determination, satellite tracking, and ionospheric correction data for CNES altimeter
- NASA BlackJack Global Positioning System receiver provides precise orbit ephemeris data
- NASA laser retroreflector array works with ground stations to track satellite and calibrate and verify altimeter measurements.

Data

- Sea-level measurement accuracy <4.2 cm (1.7 inch) required, <2.5 cm (1.0 inch) goal
- Data rate: 613 kb/s in S-band
- Data turn-around 3-hour data product within 1 hour of data reception
- Global data coverage between 66°N and 66°S latitude
- Data availability through NASA/JPL and CNES