I generated an SST output file with MODIS --> l3bin. I'm using hdftool (MATLAB) to read but I get some cell variables Seagrid, BinList, sst, qual_sst, qual_l3, and BinIndex. I like transform the sst in a matrix with their respective latitude and longitude. At the moment, I get a vector using sst{1,1} but I don't know what is the latitude and longitude.

I hope that somebody can help me

José

José,

Please see the following documents -- the second one in particular -- for
a description of the variables you are seeing in the level-3 file.

http://oceancolor.gsfc.nasa.gov/DOCS/ocformats.html#5
http://oceancolor.gsfc.nasa.gov/DOCS/Ocean_Level-3_Binned_Data_Products.pdf

You can derive the latitude and longitude from the bin_num variable in
the BinList Vdata by following the instructions in Appendix A of the
following document.

http://oceancolor.gsfc.nasa.gov/cgi/tech_memo.pl?32
http://oceancolor.gsfc.nasa.gov/SeaWiFS/TECH_REPORTS/PreLPDF/PreLVol32.pdf

Note that the variable called NUMROWS should be set to 4320
for MODIS data (assuming that you chose 4-kilometer resolution
when you created the bin file).

Regards,
Norman

P.S. SeaDAS takes care of all of the lat/lon derivations for you.

Norman,

Thanks fo your very quick response. I will read documents in detail.

Regards,

José

Just to clarify -- binned data can't be put into a "matrix" without using a map projection.   IOCCG Report 4  "Guide to the creation and use of ocean-colour, Level-3, binned data products." discusses the statistical issues behind the choice of the binning scheme used in level-3 files.