Looking closer at that, the osr refers to _osr which is python binding a GDAL C++ class. There are java binding to the same class https://gdal.org/java/org/gdal/osr/SpatialReference.html
From: Mourad HARMIM <mourad.har...@live.fr> Sent: Friday, August 2, 2024 12:05 AM To: Ian Turton <ijtur...@gmail.com> Cc: geotools-devel@lists.sourceforge.net; geotools-gt2-us...@lists.sourceforge.net Subject: Re: [Geotools-devel] Help with GeoTools : Trouble transforming coordinates CAUTION: This email originated from outside of the organization. Do not click links or open attachments unless you recognize the sender and know the content is safe: Hello Ian, Thank you for your reply. Unfortunatly a was unable to find a corresponding grid shift nor the right parameters for this specific transformation. What is suprising is epsg.io online transformer it is actually possible to do it : Transform coordinates - GPS online converter (epsg.io)<https://epsg.io/transform#s_srs=27572&t_srs=2154&x=601218.2709050&y=2428184.1367070> I found the source code of epsg.io and they implemented the transformation using "osr" library in python : epsg.io/app.py at master · maptiler/epsg.io · GitHub<https://github.com/maptiler/epsg.io/blob/master/app.py#L1380> However I could not find anything similair in java. Kind regards, Mourad Harmim. ________________________________ De : Ian Turton <ijtur...@gmail.com<mailto:ijtur...@gmail.com>> Envoyé : jeudi 1 août 2024 10:32 À : Mourad HARMIM <mourad.har...@live.fr<mailto:mourad.har...@live.fr>> Cc : geotools-gt2-us...@lists.sourceforge.net<mailto:geotools-gt2-us...@lists.sourceforge.net> <geotools-gt2-us...@lists.sourceforge.net<mailto:geotools-gt2-us...@lists.sourceforge.net>>; geotools-devel@lists.sourceforge.net<mailto:geotools-devel@lists.sourceforge.net> <geotools-devel@lists.sourceforge.net<mailto:geotools-devel@lists.sourceforge.net>> Objet : Re: [Geotools-devel] Help with GeoTools : Trouble transforming coordinates >From a quick look on epsg.io<http://epsg.io> there seems not to be a direct >transform from 27572 to 2154 so that is why the TOWGS or Bursa Wolf transform >is needed. These would appear to have a 2m accuracy so some transformation >error is to be expected. If you have a grid shift or other transformation file available then you can add it to GeoTools as described here - https://gis.stackexchange.com/questions/313512/specifying-epsg-transformation-method-in-geotools/313523#313523 Ian On Mon, 15 Jul 2024 at 01:31, Mourad HARMIM <mourad.har...@live.fr<mailto:mourad.har...@live.fr>> wrote: Hello everyone, I hope this message finds you well. My name is Mourad Harmim, a Data Engineer consultant from France. Still getting used to GeoTools, I'm facing an issue when I try to transform coordinates from Lambert 2 extended (EPSG :27572) to Lambert 93 (EPSE :2154). Here is my current situation : · When I use : this.mathTransform = CRS.findMathTransform(CRS.decode("EPSG:27572") , CRS.decode("EPSG:2154"), false) there is an error telling that Bursa Wolf parameters are missing · When I use : this.mathTransform = CRS.findMathTransform(CRS.decode("EPSG:27572") , CRS.decode("EPSG:2154"), true) I get coordinates but they seem inaccurate (I guess it is about a missing grid shift) · When I use intermediate system : Lambert 2 extended (EPSG :27572) to WSG84 (EPSG:4326) to Lambert 93 (EPSE :2154) I get better results but still inaccurate. I would like to know what it is the correct approch to have an accurate transformation between these two systems. I hope that it is not inappropriate to ask for your help through this email and I hope to hear from you soon. Thank you. Mourad Harmim. _______________________________________________ GeoTools-Devel mailing list GeoTools-Devel@lists.sourceforge.net<mailto:GeoTools-Devel@lists.sourceforge.net> https://lists.sourceforge.net/lists/listinfo/geotools-devel -- Ian Turton Notice: This email and any attachments are confidential and may not be used, published or redistributed without the prior written consent of the Institute of Geological and Nuclear Sciences Limited (GNS Science). If received in error please destroy and immediately notify GNS Science. Do not copy or disclose the contents.
_______________________________________________ GeoTools-Devel mailing list GeoTools-Devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/geotools-devel
