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[netCDF #XFZ-751322]: Longitude Problems in NetCDF Files?

Hi Paul,

It does sound like an issue with the visualization software.  NetCDF is both 
the data model and the storage file format; the data in the file is what was 
written to it. No post-processing or adjustment is applied, it is assumed that 
that will be handled upstream when the data is read from the file.  I do not 
have any experience with the tools you list, but I would be surprised if they 
do not offer some way of setting the longitudinal scale.  That is just 
supposition, however; you might try contacting their support queues and see if 
they can offer a solution to this.  Without looking at the data, however, I 
would tentatively agree with the data provider that the issue is the 
visualization software, not the data itself.  This is supported by what I know 
about netCDF, as well as the fact it opens properly in Panoply and HDFView.  It 
is also explained by the different degree scales, as you point out.

I hope this helps, have a great day,

-Ward

> Hi,
> 
> My name is Paul and I work at the National Snow and Ice Data Center. We
> recently received some test swath data from NASA in .nc format. When
> I open the data in Panoply and HDFView, it displays fine. However,
> when using ArcGIS, QGIS, and GDAL, we are having trouble with the
> longitude. The data are displaying exactly 180 degrees difference from
> where it should be even though the metadata in Panoply and HDFView
> are correct. It appears ArcGIS, QGIS, and GDAL are using a 0 to 360
> degrees scale, rather than -180 to 180, and starts the longitude at the
> International Date Line. Thus, when the files are read by these tools,
> they are displayed incorrectly.
> 
> Have you seen anything like this in the past? The data providers are
> claiming it's the software and not the data but I would like to get your
> opinion . Unfortunately, the files are rather large so I cannot email
> but have attached a screenshot. The .nc file should be over Japan but
> appears over the Atlantic.
> 
> Thanks,
> 
> Paul Moth
> User Services Office
> National Snow and Ice Data Center
> University of Colorado at Boulder
> 
> 


Ticket Details
===================
Ticket ID: XFZ-751322
Department: Support netCDF
Priority: Normal
Status: Closed
===================
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