[Geotiff] GeoTIFF

[Frank Warmerdam]

On 12-11-15 07:19 AM, Saurabh Channan wrote:
> Dear Frank,
>
>                  Hope this email finds you well.  I working with the NASA
> ESDSWG in pushing GeoTIFF though the Request For Comments (RFC) process/ EOSDIS
> system.  I am familiar with GeoTIFF file format, but if you have any
> papers/publication that you could point me to or any efforts of formalizing
> GeoTIFF as a standard in the OGC world, would be extremely helpful.  Thanks for
> your help in advance.

Saurabh,

The document is the existing reference.

   http://www.remotesensing.org/geotiff/spec/geotiffhome.html

Marit Jentoft-Nilsen (cc:ed) worked on a version of the GeoTIFF spec for
the ESDSWG RFC process back circa 2006.  I don't recall the details but
this seemed to peter out without a conclusion though I gather a fair
amount of work was done.  So we should try to get the last version from
Marit.

I am also cc:ing Carl Reed.  Circa 2009 he suggested taking up the
GeoTIFF specification as an OGC standard.  To the best of my knowledge
this did not proceed though I might easily have missed it.  I do think
there was a GeoTIFF profile for WCS prepared but that is quite a bit
less than a complete GeoTIFF spec as far as I know.

There was also a rumor of a GeoTIFF 2.0 document being prepared by
Niles Ritter, one of the original authors of the spec.  But I am not
aware of that emerging and I'm not sure how to contact Niles these
days.  I'll cc: address I have for him in my address book even though
I am doubtful about it's currency.

Beyond formalizing the existing GeoTIFF spec, these are some things
I hope to accomplish:

1) Formalize a core set of projection method id's, their relationship
to EPSG projection methods, and the applicable parameters.  Over the
years I have tried to capture "actual practice" at:

   http://www.remotesensing.org/geotiff/proj_list/

2) Nail down understanding of the difference between PixelIsArea and
PixelIsPoint.  For reference you might skim:

   http://trac.osgeo.org/gdal/wiki/rfc33_gtiff_pixelispoint

3) Clarify best practice with regard to new EPSG database versions.
The existing specification lists a set of codes but the practice
has been to assume we should accept codes from newer EPSG releases.

4) Clarify how to express "units overrides", and whether it is legal
to use an EPSG code, but then specify a different linear units code
(ie. override a meters PCS to use feet).

5) I hope we will add my proposed TOWGS84 geokey.

   http://trac.osgeo.org/geotiff/wiki/TOWGS84GeoKey

6) Provide additional examples and clarity around the topic of
    vertical datums.  There is some material on this topic at:

   http://trac.osgeo.org/geotiff/wiki/VerticalCS

I am also taking the liberty of cc:ing the GeoTIFF list in the
hopes that the community can suggest additional resources, issues,
etc. If you are not already a member of the list, I hope you will
join it.

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://home.gdal.org/warmerda
and watch the world go round - Rush    | Geospatial Software Developer