John:
(!)
RE:
http://www.remotesensing.org/geotiff/proj_list/geos.html
That reference is not correct.
(2)
RE: is geostationary a special case of vertical perspective?
I don?t think of geostationary as being special case of vertical perspective, but if the center of the image is at the equator, there are similarities. My opinion ? treat them as distinctly different.
very respectfully,
randy
On Nov 19, 2014, at 3:45 PM, John Caron <caron at ucar.edu> wrote:
> great, thanks for the clarification.
>
> the reference in CF vertical perspective projections has this proj4 reference:
>
> http://www.remotesensing.org/geotiff/proj_list/geos.html
>
> is it wrong/misleading?
>
> is geostationary a special case of vertical perspective?
>
> On Tue, Nov 18, 2014 at 6:28 PM, Randy Horne <rhorne at excaliburlabs.com> wrote:
> John:
>
> geostationary projection and vertical perspective projections are not the same.
>
> an example of a vertical projection image is one taken by a camera in space, which is not necessarily at the equator, and the data for the entire image is observed using a single exposure.
>
> the geostationary projection is that associated with scanning imagers from geostationary orbit where each image pixel covers a fixed number of radians/degrees in east/west and north/south relative to the camera?s aperture.
>
> very respectfully,
>
> randy
>
>
>
> On Nov 18, 2014, at 3:19 PM, John Caron <caron at ucar.edu> wrote:
>
>> CF TRAC ticket 72 defines "geostationary projection", accepted for 1.7.
>>
>> 1) I _think_ that "Vertical Perspective" is an earlier version of this, and it should be deprecated in favor of "geostationary". Does anyone have a different opinion?
>>
>> 2) The draft 1.7 does not yet include it, so its been hard to refer users to it.
>>
>> http://cfconventions.org/Data/cf-conventions/cf-conventions-1.7/build/cf-conventions.html#appendix-grid-mappings
>> _______________________________________________
>> CF-metadata mailing list
>> CF-metadata at cgd.ucar.edu
>> http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata
>
>
> ____________________________________
>
> Randy C. Horne (rhorne at excaliburlabs.com)
> Principal Engineer, Excalibur Laboratories Inc.
> voice & fax: (321) 952.5100
> url: http://www.excaliburlabs.com
>
>
>
>
>
____________________________________
Randy C. Horne (rhorne at excaliburlabs.com)
Principal Engineer, Excalibur Laboratories Inc.
voice & fax: (321) 952.5100
url:
http://www.excaliburlabs.com
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