A collaboration of CNES, NASA, NOAA and Eumetsat, Jason-3 will continue the reference altimetry mission for the Copernicus-MyOcean service, supporting the study of sea level variations, surface wave height and wind speed for meteorology and navigation, and continental altimetry vital for continental hydrology and operational oceanography. Jason-3 is the latest in the series of satellites that draw their heritage from the pioneering TOPEX/Poseidon altimetry satellite, launched by CNES in 1992, which marked a watershed in the study of ocean movements. In 1997-1998, TOPEX/Poseidon was the first to closely track an El Niño/La Niña episode from space, revealing all the early telltale signs of the bulge of warm water propagating across the ocean 20 to 30 centimetres above the average sea-surface height, thus providing proof of the ocean’s role in Earth’s climate system.
From its highly inclined 1,336-kilometre orbit, Jason-3 will cover 95% of the globe’s ice-free oceans every ten days. Planned to operate for three years with a possible extension to five years, it will assure the data continuity so vital to effective monitoring of global warming before being joined by two other satellites, Jason-CSA/Sentinel-6A and Jason-CSB/Sentinel-6B.
Developed by CNES and Thales Alenia Space, Jason-3 is built around a Proteus spacecraft bus. It is carrying a Poseidon-3B altimeter, the main mission instrument that measures the range from the satellite to the ocean surface, an advanced microwave radiometer (AMR) to measure emitted radiation, a CNES-designed DORIS orbit determination system, a GPS payload (GPSP) and a laser retroreflector array (LRA) developed by NASA/JPL.
On the occasion of the launch, CNES President Jean-Yves Le Gall commented: “Just weeks after the historic success of the COP21 climate conference, CNES is very proud to see the Jason-3 satellite launched to pursue our emblematic cooperation with the United States, with whom we were the first to record the rise in global sea level, marking a watershed in the study of global warming. Jason satellite data are crucial to oceanographers and climate experts all over the world and Jason-3 is now set to bring them a new tool that will play a key role in tackling climate change as part of the fleet of satellites showcased by CNES at the recent COP21 climate conference.”