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<p>Modern solution:<br>
</p>
<p>$ echo 43.37551925 -2.69713764 102.635| cs2cs -d 3 EPSG:4979
EPSG:25830+3855<br>
524534.955 4802561.478 53.074</p>
Not that when using the EPSG:xxx syntax (and not the legacy
+init=epsg:xxxx one), you need to specify input coordinates in the
order they are expected by the official definition of the CRS, here
latitude, longitude, as for all geographic CRS under the EPSG
authority (you can check the axis order by looking at the WKT output
with "projinfo EPSG:4979")
<p>You could also get that result with the legacy syntax with:</p>
<p>$ echo -2.69713764 43.37551925 102.635| cs2cs -d 3
+init=epsg:4979 +to +init=epsg:25830 +geoidgrids=egm08_25.gtx<br>
524534.955 4802561.478 53.074</p>
<p>or using the epsg:4326 code but forcing it to 3d:<br>
</p>
<p>$ echo -2.69713764 43.37551925 102.635| cs2cs -d 3 --3d
+init=epsg:4326 +to +init=epsg:25830 +geoidgrids=egm08_25.gtx<br>
524534.955 4802561.478 53.074 <br>
</p>
<p>Even<br>
</p>
<div class="moz-cite-prefix">Le 15/09/2022 à 22:18, inti luna a
écrit :<br>
</div>
<blockquote type="cite"
cite="mid:CABZ8+BCznnt3-K4okuQR5w0zEMELFXDm4KhaPRjKeOLEXfMncA@mail.gmail.com">
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<div dir="ltr">
<p>Dear PROJ community,<br>
I am using a GNSS (Emlid REACH RS2 )to collect ground control
points for drone mapping and supporting a project of
monitoring vegetation after fire. I have collected data in
LAT,LON (CRS EPSG 4326) and ellipsoidal height (m) and would
like to transform it to another CRS. Target horizontal is
EPSG: 25831 and target height is based on EGM2008 (EPSG 3855).</p>
<p>I just discovered PROJ and I am having issues with the
vertical transformation. <br>
</p>
<p>Using Linux Ubuntu 11 and installed PROJ using anaconda with:</p>
<p><conda install -c conda-forge proj></p>
<p><conda install -c conda-forge proj-data></p>
<p>I tested with:</p>
<p><echo -2.69713764 43.37551925 | cs2cs +init=epsg:4326 +to
+init=epsg:25830></p>
<p>which outputs: -2.69713764 43.37551925 which is fine.</p>
<p>However, I don't understand very well how to perform the
vertical grid shift.</p>
<p>I tried:</p>
<p>1. <echo -2.69713764 43.37551925 102.635| cs2cs
+init=epsg:4326 +vgridshift +to +init=epsg:25830
+grids=egm08_25.gtx></p>
<p>2.<echo -2.69713764 43.37551925 102.635 | proj
+init=epsg:4326 +proj=vgridshift +grids=egm08_25.gtx><br>
</p>
<p>But the first try ignores the height and the second got me an
error message:</p>
<p>"can't initialize operations that produce angular output
coordinates<br>
program abnormally terminated"</p>
<p>Thank you for your help,</p>
<p>Inti<br>
</p>
<p><br>
</p>
<p><br>
</p>
<br>
-- <br>
<div dir="ltr" class="gmail_signature"
data-smartmail="gmail_signature">
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<div><font
style="color:rgb(153,153,153);font-size:x-small"
face="arial black, sans-serif">Inti Luna<br>
</font></div>
<div><font
style="color:rgb(153,153,153);font-size:x-small"
face="arial black, sans-serif">+
</font><font
style="color:rgb(153,153,153);font-size:x-small"
face="arial black, sans-serif">34 688756449<br>
</font></div>
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color="#999999"><br>
</font></div>
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<br>
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<pre class="moz-quote-pre" wrap="">_______________________________________________
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My software is free, but my time generally not.</pre>
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