[GRASSLIST:4936] Re: Problems with importing polar data

Eric G. Miller egm2 at jps.net
Mon Nov 11 16:39:01 EST 2002


On Mon, Nov 11, 2002 at 11:36:12AM -0800, Anton B. Ivanov wrote:
> Dear all, 
> 
>   thanks to all who replied to my question on the polar projections.
>   My data is really in Polar Stereographic Projection, but AFAIK it is
>   not on the list of projections supported by GRASS (is this right?).
>   I have found that only UPS supports polar projections. 

Well, I'm confused... Apparently, Polar Stereographic is a limiting form
of Lambert Conformal Conic (as is Mercator), but the "proj" docs discuss
polar stereographic and UPS in relation to Azimuthal projections and
you're right that there doesn't seem to be a distinct Polar
Stereographic.  I did some tests against another package providing a
polar stereographic and I couldn't find a combination of parameters for
"lcc" or "stere" where the coordinates came out close.  Hmm...

>   But here's another question. How can draw a geographic grid over my
>   data?  d.grid seems to produce only rectangular grids. Or am I doing
>   something totally wrong?

AFAICT, d.grid doesn't try very hard to do a graticule correctly.  Works
okay for projected coordinate systems...

-- 
static const char signature[] = 
	"Copyright (c) 2002 Eric G. Miller <egm2 at jps.net>";




More information about the grass-user mailing list