Altimetry

Altimetry is a technique for measuring height. Satellite altimetry measures the time taken by a radar pulse to travel from the satellite antenna to the surface and back to the satellite receiver. Combined with precise satellite location data, altimetry measurements yield sea-surface heights.

Principle
How altimetry works : basic principles, reflection of echoes on several surfaces (ocean, ice, land, river), frequencies used for radar altimeters.
History
Advent of space technology in the observation of the global ocean.
Multi-satellites
Combining several altimeters significantly improve the description of ocean mesoscale variability and reduces mapping errors by up to 30 per cent.
Future evolutions
To study mesoscale variations and other phenomena more closely, future satellites will need to provide better spatial and temporal coverage. Presentation of several techniques developed today for future altimetry.