Re: another netcdf/grid question (fwd)

• To: bit-bucket <bit-bucket@xxxxxxxxxxxxxxxx>
• Subject: Re: another netcdf/grid question (fwd)
• From: Robb Kambic <rkambic@xxxxxxxxxxxxxxxx>
• Date: Wed, 7 Apr 1999 13:42:39 -0600 (MDT)

==============================================================================
Robb Kambic                                Unidata Program Center
Software Engineer III                      Univ. Corp for Atmospheric Research
rkambic@xxxxxxxxxxxxxxxx                   WWW: http://www.unidata.ucar.edu/
==============================================================================

---------- Forwarded message ----------
Date: Wed, 7 Apr 1999 12:50:24 -0600
From: Steve Chiswell <chiz@xxxxxxxxxxxxxxxx>
To: Robb Kambic <rkambic@xxxxxxxxxxxxxxxx>
Subject: Re: another netcdf/grid question (fwd)


The quasi-thinned AVN grids are on grid 255, but the RUC2 grid
is 236/255 (depending on what Cray runs the model).
The 255 code means you have to use the GDS information in the grib
file to determine the type of grid (Octet 6).

The avn on grid 255 is thinned, and must be interpolated to the Lat/lon
grid that is in the CDF file. The RUC2 grid is type 3 (Lambert COnformal).

To determine what projection each grid 255 uses, see table 6 in the grib
description document for the GDS. Then after determining what projection
is used, use table D for the appropriate grid to determine what the

If your question is in regard to the cdl, as to what you can assume for

Steve Chiswell
Unidata User Support

On Wed, 7 Apr 1999, Robb Kambic wrote:

Chiz,

I would believe Tom is correct that for grid 255 the it's a lat/lon type
grid.  But since I'm no grid expert could you confirm that's true.

Thanks,,
Robb...

I don't have the grid manual at home

==============================================================================
Robb Kambic                                Unidata Program Center
Software Engineer III                      Univ. Corp for Atmospheric Research
rkambic@xxxxxxxxxxxxxxxx                   WWW: http://www.unidata.ucar.edu/
==============================================================================

---------- Forwarded message ----------
Date: Tue, 06 Apr 1999 17:06:14 -0500
From: Tom Whittaker <tomw@xxxxxxxxxxxxx>
To: robb@xxxxxxxxxxxxxxxx
Cc: Don Murray <dmurray@xxxxxxxxxxxxxxxx>
Subject: another netcdf/grid question

Robb:

In looking over an AVN grid that Don sent me, I find the grid
code is 255, but the grid_type_code is 0 (indicating a lat/lon

grid). Is this pretty much the standard way of doing things? That is, if the grid code is 255, then I can use the

grid_type_code to indicate what parameters should be available in
the file for navigation?  (falls into that "can I safely
assume..." category...)

Thanks.

tom

--
Tom Whittaker (tomw@xxxxxxxxxxxxx)
University of Wisconsin-Madison
Space Science and Engineering Center
Phone/VoiceMail: 608/262-2759
Fax: 608/263-6738