you cite goes to the level-3 browser. If you only need a few files it is very convenient, but I'm not sure what you meand by "the upload is impossible". After setting your parameters in the pulldown lists you should see a series of small images. If you move the pointer to one of these images, you should see "SMI" and "BIN" displayed in the lower corners and a filename. If you click on one of these, a download should start. In some cases the small images may be replaced by "not available". Usually this just means the image is in the process of being updated, whcih might require a wait of a few days.
See chlor_a ATBD
for comparisons of OCI and OCx.
There are two other ways to download data: Direct Data Access
(file browswer) and Data File Search
(fill in a form to generate a list of filenames or URL's for bulk downloading).
The file you mention is an example of level-3 binned data. These files do not provide images directly, but have to mapped. The SMI files are mapped
using a cylindrical equidistant projection that many people find easy to use, but for some purposes you may want to use the
program with a different projection. Note that
can use either L3b or L3m data.