The American space agency Nasa has launched a satellite that’s expected to transform our view of water on Earth.

The Swot mission will map the precise height of rivers, reservoirs and lakes, and track ocean surface features at unprecedented scales.

It should improve flood and drought forecasts, and help researchers better understand how the climate is changing.

British scientists have been asked to help set up the spacecraft using the Bristol Channel as a benchmark.

The UK researchers are putting a suite of sensors in the estuary to “ground truth” the observations made by the satellite as it flies overhead at an altitude of 890km (550 miles).