Rotated lat lon pole grid

[Conor Sweeney]

Hi GRADS people,

I'm sorry if I'm repeating previous questions, but I'm having difficulty
plotting GRIB files which have a rotated south pole.

I am using two different limited-area models; HIRLAM and COSMO. I have
included a .ctl file from a typical data grid below. A plot of this grid,
produced by GRADS using the model's rotated lat-lon values, can be found here:

http://mathsci.ucd.ie/~hiwinds/MET_GEO.png

As can be seen, the equator and prime meridian are neither in the correct
location or orientation!

This is not, as far as I can tell, a type of grid which is supported by the
standard pdef options.

Previous posts have mentioned the use of the pdef bilin option. I have read
the grads manual, but still have no idea how this should be done.

If anyone has ever managed to plot this type of grid successfully on the
correct real-life lat-lon values, I would greatly appreciate your help and
advice on how to do so.

Thanks,

C

----

dset ^MET_GEO.grb
index ^MET_GEO.grb.idx
undef 9.999E+20
title MET_GEO.grb
*  produced by grib2ctl v0.9.12.5p39c
dtype grib 255
* Rotated LatLon grid: South pole
* lat -30.000000 lon -30.000000  rot angle 0.000000
ydef 284 linear -25.000000 0.147
xdef 438 linear -30.000000 0.147
tdef 1 linear 01Z01jan1919 1mo
zdef 1 linear 1 1
vars 1
GP0m  0 6,105,0 ** 0 m above ground Geopotential [m^2/s^2]
ENDVARS

----

Dr Conor Sweeney
UCD Meteorology & Climate Centre
Belfield, Dublin 4, Ireland.