Re: [idvusers] ISCCP DX netCDF files in IDV? Also, XML parse errors from catalogs

  • To: Tom Whittaker <whittaker@xxxxxxxx>
  • Subject: Re: [idvusers] ISCCP DX netCDF files in IDV? Also, XML parse errors from catalogs
  • From: Tod Hagan <tod@xxxxxxxxxxxxxxx>
  • Date: Tue, 12 Aug 2008 20:49:53 -0400
Tom,

Thanks for the reply.

I'm unfamiliar with CF and COARDS, but once I figure out what you're
saying or if Don or someone else specifies exactly what needs to be
changed, I can rearrange the file(s) with NCO or another tool.

Tod

On Tue, 2008-08-12 at 14:53 -0500, Tom Whittaker wrote:
> Hi Tod....
> 
> Something strikes me as odd:  GeoX is defined as a dimension of 500.
> But then declared as a variable with a shape of  "pixels".  To follow
> CF conventions, I think you want to declare it as:
> 
> int GeoX(GeoX);
> 
> so that it is a "coordinate variable" (in Sect 5.2 of the CF
> conventions - see
> <http://cf-pcmdi.llnl.gov/documents/cf-conventions/1.3/ch05s02.html>).
>  You might also need a "coordinates" attribute for your 2D fields so
> that they know to use lat_g and lon_g.  It's a little hard to
> interpret this automatically since two variables that apparently
> contain latitude values are in the file.
> 
> I note that netcdf tools does not find any coordinate system or grids
> in the file -- probably mostly due to the lack of being able to find
> geo-locations.
> 
> ....but I'm sure Don can help better than I.
> 
> tom
> 
> On Tue, Aug 12, 2008 at 2:29 PM, Tod Hagan <tod@xxxxxxxxxxxxxxx> wrote:
> > All,
> >
> > Two questions:
> >
> > First, regarding
> > http://eclipse.ncdc.noaa.gov:9090/thredds/nfdownload/iscpp-dx/2006/ISCCP.DX.0.GOE-10.2006.04.02.1800.CSU
> >
> > Is it possible to open this file with IDV? None of the options seem to
> > work. It's a netCDF file; ncview's display of its 2D fields look
> > reasonable.
> >
> > According to the global attributes it's formatted following "CF-1.0"
> > conventions. Here's an excerpt from the start of 'ncdump -c' output:
> >
> >        dimensions:
> >                pixel = 94379 ;
> >                GeoX = 500 ;
> >                GeoY = 550 ;
> >        variables:
> >                int pixel(pixel) ;
> >                        pixel:long_name = "Pixel Number" ;
> >                int lat(pixel) ;
> >                        lat:long_name = "Latitude" ;
> >                        lat:units = "degrees_north" ;
> >                        lat:scale_factor = 0.1f ;
> >                        lat:add_offset = -90.f ;
> >                int lon(pixel) ;
> >                        lon:long_name = "Longitude" ;
> >                        lon:units = "degrees_east" ;
> >                        lon:scale_factor = 0.1f ;
> >                int GeoX(pixel) ;
> >                        GeoX:long_name = "X Position" ;
> >                        GeoX:_CoordinateAxisType = "GeoX" ;
> >                int GeoY(pixel) ;
> >                        GeoY:long_name = "Y Position" ;
> >                        GeoY:_CoordinateAxisType = "GeoY" ;
> >                int gxpos(GeoX, GeoY) ;
> >                        gxpos:long_name = "X Position" ;
> >                int gypos(GeoX, GeoY) ;
> >                        gypos:long_name = "Y Position" ;
> >                int lat_g(GeoX, GeoY) ;
> >                        lat_g:long_name = "Latitude" ;
> >                        lat_g:units = "degrees_north" ;
> >                        lat_g:scale_factor = 0.1f ;
> >                        lat_g:add_offset = -90.f ;
> >                int lon_g(GeoX, GeoY) ;
> >                        lon_g:long_name = "Longitude" ;
> >                        lon_g:units = "degrees_east" ;
> >                        lon_g:scale_factor = 0.1f ;
> >
> > Second, browsing THREDDS catalogs is hampered by the number of parse
> > errors that are encountered, using both versions 2.3 and 2.5 of IDV. A
> > couple of examples:
> >
> >        Expanding xlink 
> > node:http://lead.unidata.ucar.edu:8080/thredds/topcatalog.html
> >        Error parsing xml: 
> > http://lead.unidata.ucar.edu:8080/thredds/topcatalog.html
> >        The declaration for the entity "HTML.Version" must
> >         end with '>'.
> >        The declaration for the entity "HTML.Version" must
> >         end with '>'. line:31 column:3
> >
> >        Creating 
> > ui:http://eclipse.ncdc.noaa.gov:9090/thredds/catalog/iscpp-dx/catalog.html
> >        Error parsing xml: The declaration for the entity "HTML.Version"
> >         must end with '>'.
> >        The declaration for the entity "HTML.Version" must
> >         end with '>'. line:31 column:3
> >
> > Has anyone else seen this? Is it a problem with IDV or TDS? Apparently
> > the THREDDS catalog validator that used to be available has disappeared.
> >
> > Thanks.
> >
> > Tod
> >
> > --
> > Tod Hagan
> > Information Technologist
> > AIRMAP/Climate Change Research Center
> > Institute for the Study of Earth, Oceans, and Space
> > University of New Hampshire
> > Durham, NH 03824
> > Phone: 603-862-3116
> >
> >
> > _______________________________________________
> > idvusers mailing list
> > idvusers@xxxxxxxxxxxxxxxx
> > For list information, to unsubscribe, visit: 
> > http://www.unidata.ucar.edu/mailing_lists/
> >
> 
> 
> 
-- 
Tod Hagan
Information Technologist
AIRMAP/Climate Change Research Center
Institute for the Study of Earth, Oceans, and Space
University of New Hampshire
Durham, NH 03824
Phone: 603-862-3116