to help you in using altimetry data

Aviso+ Products VisualiZation Portal
Some useful software, to read and use Aviso altimetry data
Pass locator
Use Google Earth to check a pass number for ERS-2/Envisat, Topex/Poseidon, Jason-1, GFO, OSTM/Jason-2
Cycle calendar (past and current missions)
Cycle calendars (T/P, Poseidon-1, Envisat, Jason-1)
Calendar days or julian days
Convert Calendar days in Cnes or Nasa julian days, or vice versa.