On Apr 11, 6:33 pm, robinson....@[EMAIL PROTECTED]
wrote:
> On Apr 11, 5:00 pm, David Fanning <n...@[EMAIL PROTECTED]
> wrote:
>
> > David Fanning writes:
> > > lons = -130.540 * Indgen(ysize) * 4.811e-3
> > > lats = 40.00 * Indgen(xsize) * 4.811e-3
>
> > Whoops! YSIZE and XSIZE would be reversed, certainly.
> > I'm going to order another....
>
> > Cheers,
>
> > David
> > --
> > David Fanning, Ph.D.
> > Fanning Software Consulting, Inc.
> > Coyote's Guide to IDL Programming:http://www.dfanning.com/
> > Se****e ma de ni thui. ("Perhaps thou speakest truth.")
>
> Thanks David. But in Geographic lons are like curve lines. Thus the
> lon value for the (1,1) pixel will be, in general, different respect
> to the (last,1) pixel.
David was correct about what these ENVI header values represent. You
can verify this yourself by opening an image in ENVI that is in the
Geographic Lat/Lon projection (i used the world_dem file that comes
with ENVI) and going to File->Edit ENVI Header. From there select
Edit Attributes and then Map Info... from that pulldown menu. Then
open the corresponding .hdr file for the image you opened in a text
editor. You can match up numbers to the values they represent that
way.
Jeff
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