Variable Grid possible?

[Christopher Lynnes]

Jennifer,
    The PDEF GENERAL capability looks quite useful, but made me wonder
if GrADS does or will support variable grids in netCDF, where the data
are defined according to the CF-1 convention for two-dimensional
latitude and longitude coordinate variables (http://cf-pcmdi.llnl.gov/documents/cf-conventions/1.4/cf-conventions.html#id2984605
).
    We have a service to convert our AIRS swath data to netCDF files
with this convention, which allows tools such as IDV and McIDAS-V to
read and project them.  However, attempting an sdfopen in grads
2.0.a7.1 leads to the "no discernable X coordinate" error.
    An example file can be obtained via the URL:
http://aurapar2u.ecs.nasa.gov/airspar1/daac-bin/OTF/HTTP_services.cgi?FILENAME=%2Fdata%2Fs4pa%2FAqua_AIRS_Level2%2FAIRX2RET.005%2F2006%2F161%2FAIRS.2006.06.10.202.L2.RetStd.v5.0.14.0.G07345043455.hdf&LABEL=AIRS.2006.06.10.202.L2.RetStd.v5.0.14.0.G07345043455.nc&SHORTNAME=AIRX2RET&SERVICE=NetCDF&VERSION=1.02

On Sep 10, 2009, at 7:58 AM, Jennifer Adams wrote:

> You can use the PDEF GENERAL (aka PDEF FILE) option to tell GrADS
> how to map each grid point in your 1-D vector into a 2-D lat/lon
> grid. Please see http://www.iges.org/grads/gadoc/pdef.html
> The example at the bottom of the page does something very similar to
> what you'd like to do.
> --Jennifer
>
> On Sep 9, 2009, at 7:03 AM, Reto Stauffer wrote:
>
>> Hy there
>>
>> I try to plot some Satellite-Data with Grads. It was "no problem"
>> to produce a
>> netCDF file wich i can import into GrADS and display the test-
>> dataset.
>>
>> But now i have a question up to you. Normaly GrADS plots only onto
>> a linear
>> Grid. My netCDF-File only contains a one-line-vector with longitude
>> and
>> latitude boundries.
>>
>> Is there any possibility to import long/lat as a 2-D matrix wich
>> discribes my
>> own grid? I cannot found any good information about that.
>>
>> Test-Dataset, int [0;10] with own colormap:
>> http://dudecom.ch/satpress/wp-content/uploads/2009/09/20090909_grads_colormapexample-543x400.png
>>
>> If anyone has an idea it wold be great to send me a request.
>>
>> Best regards
>> Reto, Austria
>
> --
> Jennifer M. Adams
> IGES/COLA
> 4041 Powder Mill Road, Suite 302
> Calverton, MD 20705
> jma at cola.iges.org
>
>
>

--
Christopher Lynnes             NASA/GSFC, Code 610.2
301-614-5185