Newcomers to altimetry data are often surprised when they see along-track data maps. As all Earth Observation techniques, but with a much smaller "footprint" than most sensors, altimetry satellites can't see the whole Earth at once. The workaround has been to use several satellites' data, several days (including, if possible in the future as well as in the past of a given data file), and ocean physics to estimate what is missing by optimal interpolation. That is what is behind the "multi-mission gridded maps" that a number of altimetry users have been retrieving. However the approach has its drawbacks, including not being able to retrieve details below scales of around 100 km, even when the information were in the native along-track measurements. 

Using artificial intelligence methods provides with a new approach to this problem. The deep learning scheme designed by OceaniX team at IMT Atlantique/Lab-STICC enables to better estimate the gradients between the measurements, using an a-priori knowledge of the involved physics. 

Improving data processing to provide with the most accurate and most detailed datasets is among the studies ongoing. Swot data will help, but it won't provide data everywhere and anywhere, so such processings will continue to be in order.