Just to chip in - Google Earth uses imagery in Plate Carree (plain old
lat-lon) projection. Google Maps, Yahoo Maps and some others use a
Spherical Mercator projection (i.e. Mercator with a spherical earth).
Anyway, since these are visualization tools I don't think they need
influence CF as a _data_ convention.
Cheers, Jon
On Wed, May 21, 2008 at 12:05 PM, Don Murray <dmurray at unidata.ucar.edu> 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
> *************************************************************
> Don Murray UCAR Unidata Program
> dmurray at unidata.ucar.edu P.O. Box 3000
> (303) 497-8628 Boulder, CO 80307
> http://www.unidata.ucar.edu/staff/donm
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>
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Received on Wed May 21 2008 - 05:34:03 BST
