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    <div class="moz-cite-prefix">Le 01/10/2024 à 11:04, Christian
      DOULIAC via PROJ a écrit :<br>
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    <blockquote type="cite"
      cite="mid:89c8212f2f044a45a02dae850bcf9b32@magellium.fr">
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        <p dir="auto">Hello, I would like some precision about CRS
          conversions.</p>
        <p dir="auto">I'm aware that there are some changes about
          vertical transformations with PROJ >= 9.1 as stated here :
          <a class="issue-link js-issue-link"
            data-error-text="Failed to load title" data-id="1170903012"
            data-permission-text="Title is private"
            data-url="https://github.com/OSGeo/PROJ/issues/3119"
            data-hovercard-type="pull_request"
            data-hovercard-url="/OSGeo/PROJ/pull/3119/hovercard"
            href="https://github.com/OSGeo/PROJ/pull/3119"
            moz-do-not-send="true">
          </a><a href="https://github.com/OSGeo/PROJ/pull/3119"
            class="OWAAutoLink moz-txt-link-freetext" id="LPlnk868644"
            moz-do-not-send="true">https://github.com/OSGeo/PROJ/pull/3119</a>
          <br>
          Or here : <a
href="https://proj.org/en/9.4/apps/cs2cs.html#cmdoption-cs2cs-3d"
            rel="nofollow" moz-do-not-send="true"
            class="moz-txt-link-freetext">
            https://proj.org/en/9.4/apps/cs2cs.html#cmdoption-cs2cs-3d</a>
          "Starting with PROJ 9.1, both CRS need to be 3D for vertical
          transformation to possibly happen."</p>
        <p dir="auto"><br>
          I tested it and I recreated the behavior of pre 9.1 and post
          9.1 versions :</p>
        <p dir="auto">-PROJ 8.2.0 :<br>
          echo 0 0 1000 | cs2cs +proj=longlat +datum=WGS84
          +geoidgrids=/proj-build/data/for_tests/egm96_15.tif +vunits=m
          +no_defs +type=crs +to +proj=longlat +datum=WGS84 +no_defs
          +type=crs -f "%.14f"<br>
          0.00000000000000 0.00000000000000 1017.16157913208008</p>
        <p dir="auto">-PROJ 9.2.0<br>
          echo 0 0 1000 | cs2cs +proj=longlat +datum=WGS84
          +geoidgrids=/proj-build/data/for_tests/egm96_15.tif +vunits=m
          +no_defs +type=crs +to +proj=longlat +datum=WGS84 +no_defs
          +type=crs -f "%.14f"<br>
          0.00000000000000 0.00000000000000 1000.00000000000000</p>
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    </blockquote>
    <p>Add --3d to promote the target CRS to 3D.</p>
    <p><br>
    </p>
    <p>Or use: cs2cs -f "%.14f" EPSG:4326+5773 EPSG:4979  (with lat,
      long order)<br>
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    <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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