Published: Dec. 5, 2001

Several investigators from the University of Colorado's aerospace engineering sciences department are involved with Jason 1, NASA's newest oceanography satellite, scheduled for launch Dec. 7 from Vandenberg Air Force Base, Calif.

Jason 1 will continue the mission begun in 1992 by the successful TOPEX/POSEIDON spacecraft to monitor global climate interactions between the sea and the atmosphere. The JASON 1 mission is designed to last three years.

Professors George Born and Bill Emery and Assistant Professor Steve Nerem of the Colorado Center for Astrodynamics Research primarily will be involved with the POSEIDON 2 altimeter, the spacecraft's main instrument, which will measure surface height and wave height on the seas. The altimeter will help researchers create a global map of sea level and ocean currents in near real-time.

The CU investigators will spend the first few months after launch calibrating the radar altimeter - which uses microwave radiation to measure the distance between ocean surface and the spacecraft - against Global Positioning System data and readings taken from a laser altimeter at the ocean surface, Born said.

Precise calibration of the instrument is crucial to Nerem's work, he said, which will focus on the phenomenon of sea-level rise.

"Oceanographers have long used water instruments to measure wave height and surface height," said Born. "But the only way to achieve a comprehensive global picture is using remote-sensing equipment like the altimeter aboard JASON, which can measure altitude to within centimeters."

Highly accurate information about sea level is important for companies that use offshore oil drilling facilities, said Born. "The Gulf of Mexico can be particularly turbulent," he said, "Eddies - powerful but short-lived ocean currents - can be up to four miles per hour and 180 to 250 miles in diameter, which can severely impede or damage drilling operations."

The altimeter data also can be combined with information on sea life gathered by biologists. TOPEX/POSEIDON data on the temperature and movement of ocean currents already has been used to plot the migratory movements of seals and whales.

Jason-1 will launch "piggyback" with NASA's TIMED spacecraft, on which CU-Boulder engineering professor Jeff Forbes is an investigator. CU's Laboratory for Atmospheric and Space Physics has an instrument aboard TIMED designed to study solar ultraviolet output.

Jason 1 is a joint project between NASA and the French space agency. The U.S. portion of the mission is managed for NASA's Office of Earth Science in Washington D.C. by the Jet Propulsion Laboratory in Pasadena, Calif. More information about the mission is available at The JPL home page is at