The Ocean Surface Topography Mission (OSTM) is built around a series of 'Jason' satellites (named after the mythical Greek mariner) which will collect global ocean surface data on a continuous basis for several decades. The aim is to measure the global sea surface height to an accuracy of a few centimetres every 10 days, to determine ocean circulation and mean sea level trend in support of weather forecasting, climate monitoring and operational oceanography. Launched on 20 June 2008, Jason-2 overlaps with the Jason-1 mission to secure the continuity of high accuracy satellite altimetry observations.

Further information about Jason-2 and the OSTM
Jason-2 Benefits and Applications Applications of the data collected by Jason-2 are in the areas of marine meteorology, operational oceanography, seasonal prediction and climate monitoring.	Jason-2 Satellite Jason-2 is a Low Earth Orbiting (LEO) satellite, flying at an altitude of around 1300 km. The main instruments on board are a radar altimeter, a microwave radiometer, and several precise orbit determination systems.
Products and Services Three different data products are produced and distributed to the users: the Operational Geophysical Data Record (OGDR) produced in near real time, the Interim Geophysical Data Record (IGDR) produced in 1 to 1.5 days, and the Geophysical Data Record (GDR) produced in 60 days.	Ground Segment Ground segments are a vital component of satellite operations. They are responsible for turning the satellite telemetry into useful data products. Ground segments encompass ground support facilities which control instruments, process data and provide user services and expert support.
Jason-2 Programme Background An international partnership consisting of EUMETSAT, the French CNES, and the US agencies NASA and NOAA will launch and operate the Jason-2 satellite. This event will bring satellite-based ocean altimetry into full operational status.	Satellite Altimetry To better understand the forces behind global changes of climate and to predict seasonal anomalies in weather patterns, it is vital to understand the physics of the ocean. Radar altimetry can measure the height of the sea surface and detect the slightest variation in ocean levels to the nearest centimetre.