On Tue, Sep 22, 2009 at 3:36 PM, Aaron Pratt <span dir="ltr"><<a href="mailto:aspratt2000@yahoo.com">aspratt2000@yahoo.com</a>></span> wrote:<br><div class="gmail_quote"><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;">
Hello,<br>
<br>
Is there a way to open HDF-EOS files in GrADS. I have tried to find<br>
information pertaining to this online, but have so far been unable to find<br>
anything. I would like to be able to open HDF-EOS formatted files from<br>
MODIS, CloudSat, CALIPSO, etc. (I believe HDF-EOS is the standard format for<br>
most of NASA's satellite data products.<br>
<font color="#888888"><br></font></blockquote><div><br></div><div>HDF-EOS files are nothing more than HDF-4 files with additional metadata added. Format is not the issue here since GrADS can read HDF-4. The main problem is that these files are not CF-1 (COARDS) compliant. For some Level 3 files, quantities are defined on a global 1x1 grid and a Data Descriptor File (DDF)) can be written and the file opened with "xdfopen". However, most Level 2 files are defined on swaths and such data structure is not currently supported by GrADS. (I believe COLA has plans for supporting swath data in the future, Jennifer may want to comment on it.)</div>
<div><br></div><div> I have toyed with the idea of writing a GrADS extension for dealing with swath data, but ended up using pyhdf in python for accessing such datasets. On other situations, such as for EOS aerosol data (MODIS/MISR/OMI/PARASOL) I have created my own grads readable version of datasets on the 1/4 deg GEOS-5 grid. Some of these are available on-line:</div>
<div><br></div><div> <a href="http://opendap.nccs.nasa.gov:9090/dods/AeroObs">http://opendap.nccs.nasa.gov:9090/dods/AeroObs</a></div><div><br></div><div> Good Luck,</div><div><br></div><div> Arlindo </div>
<div><br></div><div> </div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;"><font color="#888888">
Aaron Pratt,PhD<br>
NASA/ORAU Post-Doctoral Fellow<br>
Goddard Space Flight Center<br>
Greenbelt, MD 20774<br>
</font></blockquote></div><br><br clear="all"><br>-- <br>Arlindo da Silva<br><a href="mailto:dasilva@alum.mit.edu">dasilva@alum.mit.edu</a><br>