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[netCDF #DCR-102401]: ncdump question

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  • Subject: [netCDF #DCR-102401]: ncdump question
  • Date: Wed, 07 Jan 2009 14:24:59 -0700
Hi Sarah,

The x and y coordinate values are in km on the projection plane.

The ncdump -c output only shows the strictly defined "coordinate
variables" for the netCDF classic data model, which means
coordinates that have the same name as a netCDF dimension and that
are one-dimensional, such as x and y.  lat and lon in thefile you
are referring to are not netCDF classic coordinate variables, because
they are 2D variables:

        double lat(y, x) ;
                lat:units = "degrees_north" ;
                lat:long_name = "latitude coordinate" ;
                lat:standard_name = "latitude" ;
                lat:_CoordinateAxisType = "Lat" ;
        double lon(y, x) ;
                lon:units = "degrees_east" ;
                lon:long_name = "longitude coordinate" ;
                lon:standard_name = "longitude" ;
                lon:_CoordinateAxisType = "Lon" ;

Each of these has 433*622 = 269326 values, corresponding to each
point of the grid defined by the 622 x and 422 y values.  You could see
the lat and lon values in the output of the command

  ncdump -v lat,lon nam_218_20081201_0000_000.grb.nc

If that doesn't answer your question, it may be helpful to consult the
article

  http://en.wikipedia.org/wiki/Lambert_conformal_conic_projection

--Russ

Russ Rew                                         UCAR Unidata Program
address@hidden                     http://www.unidata.ucar.edu



Ticket Details
===================
Ticket ID: DCR-102401
Department: Support netCDF
Priority: Normal
Status: Closed