<div dir="ltr">Continuing this thread on a related, but also orthogonal subject:<div><br></div><div>I would like to add support for old Danish systems to proj4.<div><br></div><div>Official, and public available, procedures exist for transforming these systems to and from UTM/ETRS89. The problem is that the transformations are given as high order polynomial coefficients, and a corresponding implementation of a 2D Horner's scheme for high precision evaluation.</div><div><br></div><div>I suppose my first step would be to implement the Horner code in the proj4 code tree, and then perhaps adding the coefficients for the individual transformations as external files, preferably in a widely recognized file format, along with the grid shift files already used by proj. Perhaps then either introducing a new qualifier for specifying the specific system or overloading the +zone=... qualifier, essentially aiming at a proj syntax in the general direction of:</div><div><br></div><div>proj +proj=horner +zone=s34j</div><div><br></div><div>or similar.</div><div><br></div><div>The reason we want to do this is that the official transformations (included in out trlib software available over at <a href="https://bitbucket.org/KMS/trlib">https://bitbucket.org/KMS/trlib</a>) are used by geospatial software from numerous providers, but given the ubiquity of proj, most users probably already include proj in their code bases, hence making supporting old Danish systems much easier - to some degree even automatically accomplishable.</div><div><br></div><div><div>My colleagues and I are still just starting these considerations, so any advice, thoughts and warnings would be most welcome.</div></div><div><br></div><div>Best regards</div><div><br></div><div><font size="1">Thomas Knudsen</font></div><div><span style="font-size:x-small">Senior Adviser, PhD</span><br></div><div><font size="1">Danish Geodata Agency</font></div><div><br></div></div></div><div class="gmail_extra"><br><div class="gmail_quote">2015-11-24 2:01 GMT+01:00 Stéphane Henriod <span dir="ltr"><<a href="mailto:s@henriod.info" target="_blank">s@henriod.info</a>></span>:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">That's kind of what I meant with "automatic" :-) that the newest version of EPSG is used when a new version of Proj4 is released<div><br></div><div>So I got my answer, thanks boh of you!</div><div><br></div><div>Cheers</div><span class="HOEnZb"><font color="#888888"><div><br></div></font></span><div><span class="HOEnZb"><font color="#888888">Stéphane</font></span><div><div class="h5"><br><br>Le lundi 23 novembre 2015, Even Rouault <<a href="mailto:even.rouault@spatialys.com" target="_blank">even.rouault@spatialys.com</a>> a écrit :<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">Le lundi 23 novembre 2015 16:45:20, Stéphane Henriod a écrit :<br>
> Thanks for your answer!<br>
><br>
> And if the change request is accepted, will it be automatically be added to<br>
> the Proj4 library?<br>
<br>
There's no such thing as "automatic" ;-) But if it is included in the EPSG<br>
database then it should be available in proj.4/GDAL/libgeotiff when the next<br>
resynchronization with the EPSG database is done<br>
(<a href="https://svn.osgeo.org/metacrs/geotiff/trunk/libgeotiff/csv/README" target="_blank">https://svn.osgeo.org/metacrs/geotiff/trunk/libgeotiff/csv/README</a>)<br>
<br>
><br>
> Cheers<br>
><br>
> Stéphane<br>
><br>
> Le lundi 23 novembre 2015, Noel Zinn (cc) <<a>ndzinn@comcast.net</a>> a écrit :<br>
> > The following link is for a change request for the EPSG Dataset. You do<br>
> > have to have an account, but that’s simple if you’ve never logged in<br>
> > before.<br>
> ><br>
> > <a href="http://www.epsg.org/MakeChangeRequest" target="_blank">http://www.epsg.org/MakeChangeRequest</a><br>
> ><br>
> ><br>
> > Noel Zinn, Principal, Hydrometronics LLC<br>
> > <a href="tel:%2B1-832-539-1472" value="+18325391472" target="_blank">+1-832-539-1472</a> (office), <a href="tel:%2B1-281-221-0051" value="+12812210051" target="_blank">+1-281-221-0051</a> (cell)<br>
> > <a>noel.zinn@hydrometronics.com</a><br>
> > <javascript:_e(%7B%7D,'cvml','<a>noel.zinn@hydrometronics.com</a>');> (email)<br>
> > <a href="http://www.hydrometronics.com" target="_blank">http://www.hydrometronics.com</a> (website)<br>
> ><br>
> > *From:* Stéphane Henriod <javascript:_e(%7B%7D,'cvml','<a>s@henriod.info</a>');><br>
> > *Sent:* Monday, November 23, 2015 5:40 AM<br>
> > *To:* <a>proj@lists.maptools.org</a><br>
> > <javascript:_e(%7B%7D,'cvml','<a>proj@lists.maptools.org</a>');> ;<br>
> > <a>metacrs@lists.osgeo.org</a><br>
> > <javascript:_e(%7B%7D,'cvml','<a>metacrs@lists.osgeo.org</a>');><br>
> > *Subject:* [Proj] Having a CRS added in the common libraries<br>
> ><br>
> > Dear all<br>
> ><br>
> > I am new to both lists (proj and metacrs) so my apologies for<br>
> > cross-posting, I am not quite sure where my question belongs.<br>
> ><br>
> > I am working in the beautiful country of Kyrgyzstan, which happens to<br>
> > have developed a new national geodetic framework. One of the outputs is<br>
> > a coordinate system (Kyrg06), divided in 5 zones.<br>
> ><br>
> > As far as I know, this coordinate system is not yet available in any<br>
> > common library / software and is neither in the EPSG list.<br>
> ><br>
> > Is there any standard process to get a sort of international recognition?<br>
> > This system has been approved by the government and thus has a legal<br>
> > validity in this country. But it will always be difficult to convince<br>
> > people to use it as long as it's not readily available in the common<br>
> > software (and thus in the underlying libraries). As a result, many GIS<br>
> > users end up working with UTM or other not-so-optimal.<br>
> ><br>
> > Thanks a lot in advance for your hints and advice on this matter<br>
> ><br>
> > Cheers<br>
> ><br>
> > Stéphane<br>
> ><br>
> ><br>
> > --<br>
> ><br>
> > "Le mot progrès n'aura aucun sens tant qu'il y aura des enfants<br>
> > malheureux" -- Albert Einstein<br>
> ><br>
> > "Si les contacts avec les étrangers lui étaient permis, [le citoyen<br>
> > ordinaire] découvrirait que ce sont des créatures semblables à lui-même<br>
> > et que la plus grande partie de ce qu'on lui a raconté d'eux est fausse.<br>
> > Le monde fermé, scellé, dans lequel il vit, serait brisé, et la crainte,<br>
> > la haine, la certitude de son bon droit, desquelles dépend sa morale,<br>
> > pourraient disparaître" -- George Orwell ("1984")<br>
> ><br>
> > “When you travel, remember that a foreign country is not designed to make<br>
> > you comfortable. It is designed to make its own people comfortable." --<br>
> > Clifton Fadiman<br>
> ><br>
> > Photos de voyages, photos de montagne: <a href="http://www.henriod.info" target="_blank">http://www.henriod.info</a><br>
> ><br>
> > ------------------------------<br>
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<br>
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<br>
</blockquote></div></div></div><div class="HOEnZb"><div class="h5"><br><br>-- <br><div dir="ltr"><div><div dir="ltr"><div dir="ltr"><div dir="ltr"><div dir="ltr"><div dir="ltr"><br></div><div dir="ltr">"Le mot progrès n'aura aucun sens tant qu'il y aura des enfants malheureux" -- Albert Einstein<br><br>"Si les contacts avec les étrangers lui étaient permis, [le citoyen
ordinaire] découvrirait que ce sont des créatures semblables à lui-même
et que la plus grande partie de ce qu'on lui a raconté d'eux est fausse.
Le monde fermé, scellé, dans lequel il vit, serait brisé, et la
crainte, la haine, la certitude de son bon droit, desquelles dépend sa
morale, pourraient disparaître" -- George Orwell ("1984")<br><br>“When you travel, remember that a foreign country is not designed to
make you comfortable. It is designed to make its own people
comfortable." -- Clifton Fadiman<br><br>Photos de voyages, photos de montagne: <a href="http://www.henriod.info/" target="_blank">http://www.henriod.info</a><span dir="ltr"><span dir="ltr" title="Appeler ce numéro de téléphone en/au(x) Tadjikistan avec Skype : +992934624662"><span> </span></span> <br></span></div></div></div></div></div></div></div><br>
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