Fifteen years ago this ground-breaking instrument, called a radar altimeter, was launched into orbit, despite speculation of its usefulness from the wider oceanographic community. Although it took over a decade for its full impact to be realised, its accomplishments have been so great that it is credited with having revolutionised the field of physical oceanography.
In honour of altimetry, oceanographers, glaciologists, hydrologists and geodesists from around the world have gathered in Venice Lido, Italy, at the '15 Years of Progress in Radar Altimetry' symposium, organised by ESA and the French Space Agency (CNES), to celebrate its success. Signifying its vast array of achievements, many have come to honour it for different reasons. According to one of the pioneers of the altimeter, Massachusetts Institute of Technology's (MIT) Carl Wunsch, its biggest contribution is conceptual rather than scientific because it changed the way scientists viewed the ocean.
"The greatest achievement of the altimeter is that it has showed us that the ocean system changes rather dramatically everyday and has shifted the view of it from this almost geological phenomenon creeping along very slowly to something much more interesting in which fluid is moving in all directions at all times," Wunsch said.
The radar altimeter offers valuable information on the state of the ocean by providing measurements of the height of the ocean surface. This is done by sending 1800 separate radar pulses down to Earth per second then recording how long their
Contact: Mariangela D'Acunto
European Space Agency