Thanks for your answer. Actually I'm getting data from a ftp, which is "ftp://podaac-ftp.jpl.nasa.gov/allData", where you can find the saral option, go further a few more options and get the file with altika data products inside. So, I am getting altika data from this website.
The problem that I am having is because I am trying to work with two tracks which are plotting at wrong location. We can see the nominal position of Saral/Altika tracks through the "Visu Nominal Tracks" on Google Earth. The tracks that I want to work are 0749 and 0205 and should be on Southern Atlantic Ocean, close to Rio de Janeiro's coast, but it is located at Pacific Ocean instead. Another problem is because both tracks are plotting at same position (two different tracks located at same position, it is weird). Besides that, I worked with another track from the same ftp database. I used the same data for the track 0648 and the data was all right! All data that I tryied to work with was from 2013 to 2015.
So, the data looks to be wrong. I would like to know if you guys can give me some tips or if there is a problem with Altika data.