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Dear Mary,<br>
<br>
I just wanted to report a subtle issue that we ran into with ncl
6.0. Since here at DWD we are running a SuSe system with gcc 4.1.2,
we had to compile ncl 6.0 from source. Everything went more or less
smoothly, except for the following subtle GRIB2 problem that we
encountered:<br>
<br>
The compilation was performed WITH GDAL(v1.9.0) and WITH GRIB2
(g2clib v1.2.1) support.<br>
<br>
When trying to read a Grib2 file containing Sattelite data, I got
the following error from ncl_filedump:<br>
<em class="quotelev1"><br>
getpdstemplate: PDS Template 4.31 not defined.
</em><br>
<em class="quotelev1">warning:Error unpacking GRIB record section 4.
</em><br>
<em class="quotelev1">fatal:Could not open(CTH_DE_201111070600.grb2)</em><br>
<br>
However, the current g2clib (both, the original one from NCEP
(v1.2.3) and the modified one you provide (v1.2.1)) do contain the
required template 4.31. The problem seems to be related to the fact,
that GDAL also includes g2clib, but in a somewhat outdated version
(gdal-1.9.0/frmts/grib/degrib18/g2clib-1.0.4), which does not
contain Template 4.31. It seems that ncl is linked against the
"wrong" g2clib, if GDAL is compiled in.<br>
<br>
If ncl is compiled without GDAL support, then the GRIB2 file
containing the satellite data can be read without problems.<br>
<br>
Since we wanted to have GDAL compiled in, we looked for an
alternative solution. The following worked for us:<br>
When compiling GDAL, one can switch off the GRIB driver by using the
configure flag "--without-grib". Then, ncl is linked against the
correct g2clib. However, I'm not sure, whether this has any unwanted
side-effects.<br>
<br>
Is there a more 'elegant' way of telling ncl which g2clib library to
use?<br>
<br>
Cheers,<br>
Daniel<br>
<pre class="moz-signature" cols="72">--
---------------------------
Dr. Daniel Reinert
Deutscher Wetterdienst
Research and Development
63067 Offenbach am Main
Germany
Phone: +49 69 8062 2060
--------------------------
</pre>
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