Re: [ferret_users] regridding data between curvilinear grids

[Hein Zelle <hein@xxxxxxxxxxx>]

Hi Ansley,

> The CURV_TO_RECT regridding function will let you regrid both fields to 
> a common recilinear grid so you can compare them.

Thanks! I'll try that, it sounds excactly like what I was looking for.

> I also wonder, since you know the projection, if you couldn't perhaps 
> "reverse" the projection analytically?  Perhaps take a look at the 
> script mp_lambert.jnl which can be used to set up the Lambert projection 
> projection from a rectangular grid.  Just talking off the top of my head 
> here, I have not really thought this through.

In theory - yes. 

I already have the coordinates of each gridpoint in lat and lon, I
just don't have any regular axes I can use for ferret's regridding
(grid rows and columns are not regular in lat and lon). What I would
need to do is to overlay one of the projections on top of the other in
"index coordinates", and then have ferret regrid one to the other. I
think that could be done, but only if the two grids use the same
central longitude and latitude (for the cone on which they are
projected). In my case the two grids do not share the same center
point, so I don't think the "i" and "j" directions would be parallel -
bringing me nowhere.

I may be getting this all wrong, so feel free to correct the above.
Thanks for your help!

       Hein

--

 Unix is user friendly. It's just very particular about who 
 it's friends are.

 Hein Zelle                     hein@icce.rug.nl
	                        http://www.icce.rug.nl/~hein