[RegCNET] Error opening RegCM4.1.1 output in Grads

[Graziano Giuliani]

On 06/15/2011 08:04 AM, Shahbaz Mehmood wrote:
> Dear All,
>
> After the successful run of RegCM4.1.1 with input data of NNRP1, When
> I try to open the model output NC files e.g ATM.NC with Ferret, Its
> ok. But when I tried to open it with Grads, it gives following error.
>
>   "SDF file has no discernable X coordinate"
>
> Thanks in advance if any one can help me out.
[...]

You cannot directly use sdfopen for GrADS with RegCM netCDF files: the RegCM 
model works on a projected grid. You need to give GrADS information on the 
native RegCM grid, as GrADS is limited to plot without hint just regular lat-lon 
grid. This means building a CTL file. Two helper programs are provided for this, 
GrADSNcPlot and GrADSNcPrepare in the postproc directory.

The first one prepares ancillary files, launches grads binary for you (if 
correctly installed in path at latest version) and after completion removes the 
ancillary files (ctl and projection info).
The second one just writes ancillary files and exit.

Another path is use the regridder script, interpolate model output to a regular 
lat.-lon grid and then sdfopen that.

Ciao!

Graziano.

-- 
Graziano Giuliani - Earth System Physics Section
The Abdus Salam International Centre for Theoretical Physics
Strada Costiera, 11 - I - 34151 Trieste Italy