Jason-2

Jason-2
Name	Jason-2
Mission type	Earth observation
Operator	National Aeronautics and Space Administration / Centre National d'Études Spatiales / European Organisation for the Exploitation of Meteorological Satellites / National Oceanic and Atmospheric Administration
COSPAR ID	2008-014A
SATCAT	32679
Spacecraft type	Oceanography satellite
Manufacturer	Thales Alenia Space / EADS Astrium
Launch mass	534 kg
Launch date	2008-06-20
Launch rocket	Delta II
Launch site	Vandenberg Air Force Base
Orbit type	Non-Sun-synchronous, low Earth orbit
Mission duration	8 years (operational)

Jason-2

Jason-2 was an international radar altimetry satellite mission dedicated to precise measurement of global sea-surface height, ocean circulation, and sea-level change. Developed by a partnership of National Aeronautics and Space Administration, Centre National d'Études Spatiales, European Organisation for the Exploitation of Meteorological Satellites, and National Oceanic and Atmospheric Administration, it continued and extended the time series established by previous missions. The spacecraft provided data used across climate science, oceanography, meteorology, and operational applications such as marine forecasting and coastal monitoring.

Overview

The mission was conceived as the follow-on to earlier altimetry programs led by NASA and CNES, building on heritage from missions like TOPEX/Poseidon and servicing long-term records used in reports by the Intergovernmental Panel on Climate Change and analyses by the United Nations Framework Convention on Climate Change. Managed jointly by agencies including NOAA and EUMETSAT, the program coordinated with space industry partners such as Thales Alenia Space and launch providers like United Launch Alliance. Objectives emphasized continuity of sea-surface height measurements, support for operational centers such as Copernicus-affiliated services, and contributions to studies by institutions including Scripps Institution of Oceanography and Woods Hole Oceanographic Institution.

Mission Design and Instruments

The satellite carried a suite of instruments including a dual-frequency radar altimeter, a microwave radiometer, a GPS receiver for precise orbit determination, and a DORIS tracking system. The radar altimeter was derived from technology used on TOPEX/Poseidon and designed to measure range to the sea surface with centimeter-level accuracy, complementing radiometric atmospheric corrections from the microwave radiometer for water vapor retrievals. Precise orbit determination combined data from the Global Positioning System constellation, the DORIS system, and satellite laser ranging links from networks coordinated by organizations like International Laser Ranging Service. Instrument calibration and validation involved agencies and labs such as Jet Propulsion Laboratory and CNES Toulouse facilities.

Launch and Orbit

Launched on a Delta II from Vandenberg Air Force Base in June 2008, the spacecraft was injected into a non-Sun-synchronous, near-circular orbit with an inclination optimized for global ocean coverage. The ground track repeated every 10 days, matching the repeat cycle established by predecessors to facilitate long-term comparison and cross-calibration with missions such as Jason-1 and Envisat. Orbit control maneuvers were performed by teams at operations centers including NOAA Satellite Operations Facility and EUMETSAT Operations Centre to maintain the reference ground track used by operational oceanography centers like Naval Oceanographic Office and research groups at Plymouth Marine Laboratory.

Operations and Data Products

Operational command, control, and data dissemination were handled by the international partnership, with near-real-time products delivered to users including Global Climate Observing System participants and operational forecasting centers. Data products included along-track sea-surface height, significant wave height, wind speed over the ocean, and geophysical corrections packaged for use by researchers at National Centers for Environmental Prediction, European Centre for Medium-Range Weather Forecasts, and climate researchers at NOAA’s National Centers for Environmental Information. Reprocessed data and calibration datasets were maintained by science teams at institutions such as Scripps Institution of Oceanography and CNES, and the mission contributed to consolidated multi-mission products assembled by groups like AVISO.

Scientific and Societal Contributions

The mission provided critical observations for quantifying global mean sea-level rise, contributing evidence to assessments by the Intergovernmental Panel on Climate Change and national climate assessments. Data supported studies of ocean heat content by researchers at Lamont–Doherty Earth Observatory and provided inputs to ocean circulation models developed by groups at GFDL and Met Office Hadley Centre. Operationally, measurements improved storm surge modeling used by National Hurricane Center and coastal management decisions by agencies such as Federal Emergency Management Agency and regional authorities. The mission’s continuity enhanced long-term time series relied upon by initiatives like the Global Sea Level Observing System.

End of Mission and Legacy

After fulfilling its primary objectives and extending the altimetry record, the spacecraft was retired following planned end-of-life operations coordinated by partner agencies. Its long, overlapping record with contemporaneous missions enabled rigorous cross-calibration and provided a robust dataset that underpins ongoing climate monitoring and oceanographic research. The legacy continues through successor missions and integrated datasets maintained by organizations including NOAA, ESA, and CNES, and in scientific literature from institutions like Scripps Institution of Oceanography and Woods Hole Oceanographic Institution that build on the mission’s observations.

Category:Earth observation satellites Category:Satellites launched in 2008