Hi Don,
Vertical Perspective projection made it into CF 1.2, which is why I
didn't mention it. Yes, I was also assuming that GoogleEarth uses a
tilted perspective-type projection. But for general whole-globe views,
the orthographic projection is a useful alternative (and obviously the
limiting case of vertical perspective - i.e. the perspective point is at
inifinity).
Regards,
Phil
On Wed, 2008-05-21 at 07:05 -0400, Don Murray wrote:
> Phil/Ethan-
>
> Philip Bentley wrote:
>
> > An obvious one perhaps, but one which we may find increasingly
> useful /
> > relevant in light of the rise and rise of GoogleEarth-type
> applications,
> > is the Orthographic projection. This being the classic 'view from
> space'
> > projection.
> >
> > Same grid mapping parameters as the other azimuthal projections,
> viz.
> >
> > grid_mapping_name = "orthographic"
> >
> > longitude_of_projection_origin
> > latitude_of_projection_origin
> > false_easting
> > false_northing
> >
> > (though off the top of my head I can't think of a scenario where one
> > would want to use the last two params).
>
> I think GE actually uses a tilted perspective view. But,
> I think CF should support the Vertical Perspective with
> an ellipsoid. EUMETSAT has GRIB messages with this projection
> and an elliptical earth.
>
> Don
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