RE: Resampling from lat/lon to projection

• To: <dmurray@xxxxxxxxxxxxxxxx> "Tor Christian Bekkvik" <torc@xxxxxx>
• Subject: RE: Resampling from lat/lon to projection
• From: Kjell Roang <kjell@xxxxxx>
• Date: Thu, 20 Mar 2003 16:41:32 +0100

Don -

> -----Original Message-----
> From: Don Murray [mailto:dmurray@xxxxxxxxxxxxxxxx]
> Sent: 20. mars 2003 16:08
> To: dmurray@xxxxxxxxxxxxxxxx
> Cc: Kjell Roang; visad-list@xxxxxxxxxxxxx; Richard D Gonzalez; Tor
> Christian Bekkvik
> Subject: Re: Resampling from lat/lon to projection
>
>
> Kjell-
>
> Don Murray wrote:
>
> > You could still use GeoTools on the VisAD adapter by creating
> > a GeoToolsCoordinateSystem that would take a GeoTools object
> > and use that to do the conversion.  I'll look at GeoTools when
> > I get a chance (maybe next week).  MapProjectionDisplay
> > is in the examples directory.  The examples do not have
> > packages, so you would have to cd to the examples directory
> > and run java MapProjectionDisplay.
>
> I just took a quick look at the GeoTools source and it looks
> like you could create a GeoToolsProjectionCoordinateSystem
> that would extend visad.georef.MapProjection and take
> a uk.ac.leeds.ccg.geotools.projections.Projection as
> a constructor.  The toRef method (ref being lon, lat)
> would call Projection.unproject() for each x,y and
> the CS.fromRef() would call Projection.project().
> You'd have to get the indices of lat/lon set right,
> but MapProjection has hooks for this.  The defaultMapArea
> could be defined from Projection.projectedExtent.
>
> Again, I'd reiterate Tom's suggestion that you let VisAD do
> as much of the hard work automagically instead of having to
> manually do the transforms.

I fully agree. I would try to use VisAd as much as possible, and the
conversation with you has given me hints how to use another projection
package inside VisAd. I must then find a way to put GRIB data into VisAd and
get images and data out of VisAd.

Kjell

>
> Don
> *************************************************************
> Don Murray                               UCAR Unidata Program
> dmurray@xxxxxxxxxxxxxxxx                        P.O. Box 3000
> (303) 497-8628                              Boulder, CO 80307
> http://www.unidata.ucar.edu/staff/donm
> *************************************************************
>
>

• Follow-Ups:
  • Re: Resampling from lat/lon to projection
    • From: Don Murray

• References:
  • Re: Resampling from lat/lon to projection
    • From: Don Murray