[Geotiff] Geotiffs for mapping of imaginary worlds

[Frank Warmerdam]

On 11/24/05, Mike Parkes <mikeparkes at rogers.com> wrote:
> What I am interested in doing is using GIS software to map an imaginary
> planet.
>
> My starting point is a number of raster images in different projections that
> cover parts of the planet (e.g. Robinson projection for a world map,
> different projection for larger-scale maps). I want to be able to integrate
> and overlay these images, then create vector shapefiles. I'm only concerned
> with surface mapping (no elevation modeling), at least for now.
>
> The imaginary world is perfectly spherical, but a different size from Earth.
> Hence, to georeference my images, I need a GIS program that allows
> user-defined datums.
>
> I have been investigating the GeoTiff file format, and (through the Listgeo
> and geotifcp utilities), it has all the machinery that I need to create an
> imaginary datum, a map projection and to attach the datum and projection to
> an image. However, I haven't been able to find a software package that can
> actually interpret and make use of this specialized GeoTiff information.
>
>
>
> Which free or low-cost GIS software packages can utilize Geotiff's
> capability for user-defined datums?

Mike,

What exactly do you want these packages to do?
The GDAL software, and OpenEV should support
arbitrary user-defined ellipsoids just fine.

  http://www.gdal.org/
  http://openev.sf.net/

I would add, unless you want to "simulate" geoid
variation and survey area you don't really need to
fully define a datum.  You essentially want to map
on a perfectly spherical world with but with an
radius different than the earth.   That should be
straight forward.

Best regards,
--
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I set the clouds in motion - turn up   | Frank Warmerdam, warmerdam at pobox.com
light and sound - activate the windows | http://pobox.com/~warmerdam
and watch the world go round - Rush    | Geospatial Programmer for Rent