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<p>Hi Martin,</p>
<p>thanks for letting us know. <br>
</p>
<p>A few points:</p>
<p>- I'm not sure the PROJ project has a plan to adopt GGXF as being
a format it would read out-of-the-box, mostly because we're quite
happy with the Geodetic TIFF Grids (GTG) that we have been using
in production for more than 2 years now, including in a CDN
context. And also because reading netCDF-4 file would mean to add
a new heavy dependency to PROJ. If GGXF eventually comes into
common usage, we'll probably use a converter script to create GTG
files from it, unless it comes with real unique features, used in
practice, that we can't reasonably port to GTG. So if someone is
interested by that activity in the context of this code sprint,
developing such script, probably using netcdf4-python to read GGXF
and GDAL Python bindings to write GeoTIFF, would probably the most
useful outcome.</p>
<p>- regarding GIGS, PROJ has a subset of (I'm not sure which
version of) them as scripts executable by its gie utility in
<a class="moz-txt-link-freetext" href="https://github.com/OSGeo/PROJ/tree/master/test/gigs">https://github.com/OSGeo/PROJ/tree/master/test/gigs</a></p>
<p>Even<br>
</p>
<div class="moz-cite-prefix">Le 21/02/2022 à 15:22, Martin
Desruisseaux a écrit :<br>
</div>
<blockquote type="cite"
cite="mid:8a025c8d-6733-0452-c928-6f6b79f30931@geomatys.com">
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<p>Hello all</p>
<p align="justify">The joint OGC/OSGeo/ASF code sprint will start
in 2 weeks, with a pre-event webinar in 2 days (Wednesday this
week). This event is free for anyone to participate, and thanks
to Ordnance Survey sponsor a little bit of funding will be
available for participants who apply and who are selected as
eligible (more details to be provided by OGC later). The
schedule is below:</p>
<blockquote>
<p><a class="moz-txt-link-freetext"
href="https://github.com/opengeospatial/developer-events/wiki/2022-Joint-OGC-%E2%80%93-OSGeo-%E2%80%93-ASF-Code-Sprint"
moz-do-not-send="true">https://github.com/opengeospatial/developer-events/wiki/2022-Joint-OGC-%E2%80%93-OSGeo-%E2%80%93-ASF-Code-Sprint</a></p>
</blockquote>
<p>Any development activity related to OGC standards can be
proposed. Below are 2 proposals that may be relevant to PROJ:</p>
<p><br>
</p>
<h3>Proposal: GGXF implementation</h3>
<p align="justify">The Gridded Geodetic data eXchange Format
(GGXF) is an OGC standardization effort for distributing datum
shift grids, geoid models, and more geodetic gridded data. It
has the same goal than the GeoTIFF files that PROJ currently
uses for this purpose. Chris Crook, who worked on the PROJ
GeoTIFF format, is also a very active participant to the GGXF
effort, together with Roger Lott, the main editor of ISO 19111
(referencing by coordinates) and ISO 19162 (WKT 2) standards.
Some other participants in the working group are from ESRI or
from International Association of Geodesy (IAG). The GGXF
standard uses the netCDF-4 format. A draft of the GGXF standard
and a prototype in Python are available. The code sprint would
be an opportunity for volunteers for starting an implementation
in PROJ, with Chris, Roger and other peoples present for
answering questions and collecting feedback. For more details,
see:</p>
<blockquote>
<p><a class="moz-txt-link-freetext"
href="https://github.com/opengeospatial/developer-events/tree/master/2022/Joint-OGC-OSGeo-ASF-Code-Sprint%202022/ideas/GGXF"
moz-do-not-send="true">https://github.com/opengeospatial/developer-events/tree/master/2022/Joint-OGC-OSGeo-ASF-Code-Sprint%202022/ideas/GGXF</a></p>
</blockquote>
<p><br>
</p>
<h3>Proposal: GIGS implementation</h3>
<p align="justify">The Geospatial Integrity of Geoscience Software
(GIGS) is an IOGP effort for providing tests for coordinate
operations. IOGP is the organization maintaining the widely-used
EPSG geodetic database. GIGS tests are available as dataset (CSV
files), web service and executable JUnit tests. The JUnit tests
can be executed on any GeoAPI 3.0 implementation, including PROJ
through the PROJ-JNI binding. The Java language is used for GIGS
tests because it is currently the only language providing
implementation-neutral API for referencing services (Python
could be another candidate but the GeoAPI interfaces in Python
are still in development). The code sprint would be an
opportunity for volunteers to help upgrading to GIGS 2 and
complete the tests (in Java), tests them on PROJ, and continue
development of Python interfaces.<br>
</p>
<blockquote>
<p><a class="moz-txt-link-freetext"
href="https://github.com/opengeospatial/developer-events/tree/master/2022/Joint-OGC-OSGeo-ASF-Code-Sprint%202022/ideas/GIGS"
moz-do-not-send="true">https://github.com/opengeospatial/developer-events/tree/master/2022/Joint-OGC-OSGeo-ASF-Code-Sprint%202022/ideas/GIGS</a></p>
</blockquote>
<p><br>
</p>
<h3>Mentoring</h3>
<p align="justify">In addition to volunteers for above proposals,
the PROJ project can also propose tutorials for beginners. On
the mentor stream, developers will have the opportunity to give
their first steps using the standards and projects, and
hopefully this will build an engagement which will continue past
the code sprint. More information are there:</p>
<blockquote>
<p><a class="moz-txt-link-freetext"
href="https://dev.to/doublebyte/2nd-open-software-and-open-standards-code-sprint-call-for-mentors-1g0o"
moz-do-not-send="true">https://dev.to/doublebyte/2nd-open-software-and-open-standards-code-sprint-call-for-mentors-1g0o</a></p>
</blockquote>
<p><br>
</p>
<p>Home page and registration: <a class="moz-txt-link-freetext"
href="https://developer.ogc.org/sprints/15/"
moz-do-not-send="true">https://developer.ogc.org/sprints/15/</a></p>
<p> Martin</p>
<p><br>
</p>
<br>
<fieldset class="moz-mime-attachment-header"></fieldset>
<pre class="moz-quote-pre" wrap="">_______________________________________________
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<a class="moz-txt-link-freetext" href="https://lists.osgeo.org/mailman/listinfo/proj">https://lists.osgeo.org/mailman/listinfo/proj</a>
</pre>
</blockquote>
<pre class="moz-signature" cols="72">--
<a class="moz-txt-link-freetext" href="http://www.spatialys.com">http://www.spatialys.com</a>
My software is free, but my time generally not.</pre>
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