Oceanography satellites orbiting the Earth,artwork. They are Topex-Poseidon (left) and Jason-1 (right). Topex-Poseidon,launched in 1992,was a joint mission between NASA and the CNES (the French space agency). It mapped ocean surface topography,the first satellite to do so extensively. This allowed global monitoring of sea level,tides,ocean currents and oscillations,ocean circulation,and climate change. The measurements were made with two radar altimeters,named Topex (topography experiment) and Poseidon. The satellite was shut down in 2006 following a malfunction. Its successor,Jason-1,was launched in 2001 |