Re: 20000321: Georeferencing classes

> Has anyone out there developed any VisAD Data objects for
> georeferencing? Right now there's visad.MapProjection for defining
> map projections and I'm working on a class (LatLonTuple) as a
> data object representing lat/lon points.  Before I go too
> far down the path, I wanted to see if someone else has already
> been there.  I was thinking that perhaps those working on the
> GeoVista project or Ugo might have something.

Just to clarify, the basics needed for georeferencing are
built into VisAD, as the CoordinateSystem class and the
static instances RealType.Latitude, RealType.Longitude and
RealType.Altitude.

There is also a class EarthVectorType that extends
RealTupleType (indirectly via RealVectorType) for Earth-based
wind and current vectors that don't transform according to
the usual Jacobean rule in coordinate transforms.  And there
is some specialized logic down in the display clases for
dealing with earth coordinates (much of this worked out in
collaboration with Don).

So I think Don is asking for classes that build on these
existing VisAD basics.  CoordinateSystem is pretty generic
(e.g., it also deals with color coordinate systems) so he's
looking for specializations for Earth coordinates.  One
example would be the various slightly different
latitude-longitude definitions.

Cheers,
Bill
----------------------------------------------------------
Bill Hibbard, SSEC, 1225 W. Dayton St., Madison, WI  53706
hibbard@xxxxxxxxxxxxxxxxx  608-263-4427  fax: 608-263-6738
http://www.ssec.wisc.edu/~billh/vis.html