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Mapping ocean height from space

This is an unprecedented time for the study of the oceans.

Space agencies are now flying six satellite altimeters, returning large volumes of data on the height and shape of the sea surface - and in rapid time.

The information is fed into all manner of applications, from forecasting the weather to understanding the migratory habits of marine creatures.

Remko Scharroo from Eumetsat explained to our correspondent Jonathan Amos what it meant to have six ocean altimeters.