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<div class="moz-cite-prefix">Le 21/02/2023 à 11:00, Lesparre, Jochem
a écrit :<br>
</div>
<blockquote type="cite"
cite="mid:AM0P192MB0482DD111B18683457FC364FEFA59@AM0P192MB0482.EURP192.PROD.OUTLOOK.COM">
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<p class="MsoNormal"><span style="mso-fareast-language:EN-US">Dear
Even,<o:p></o:p></span></p>
<p class="MsoNormal"><span style="mso-fareast-language:EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="mso-fareast-language:EN-US"
lang="EN-GB">Sorry, I was using PROJ 8.2.1 as I didn’t
expect the PROJ behaviour had changed since that version
(see updated command results below).<o:p></o:p></span></p>
<p class="MsoNormal"><span style="mso-fareast-language:EN-US"
lang="EN-GB"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="mso-fareast-language:EN-US"
lang="EN-GB">We use the ETRF2000 realisation like most other
NMAs, as this is recommended by EUREF for georeferencing,
not ETRF2014! Therefore, ETRS89 should not be transformed to
ETRF2014 with a null transformation. </span></p>
</div>
</blockquote>
<p>The null transformation between ETRS89 and ETRF2014 comes with
the definition of the datum ensemble ETRS89 (cf change
<a class="moz-txt-link-freetext" href="https://github.com/OSGeo/PROJ/issues/3263">https://github.com/OSGeo/PROJ/issues/3263</a>)<br>
</p>
<p><br>
</p>
<blockquote type="cite"
cite="mid:AM0P192MB0482DD111B18683457FC364FEFA59@AM0P192MB0482.EURP192.PROD.OUTLOOK.COM">
<div class="WordSection1">
<p class="MsoNormal"><span style="mso-fareast-language:EN-US"
lang="EN-GB">The correct transformation routes are:<o:p></o:p></span></p>
<ul style="margin-top:0cm" type="disc">
<li class="MsoListParagraph"
style="margin-left:0cm;mso-list:l0 level1 lfo1"><span
style="mso-fareast-language:EN-US">RD -> Amersfoort
-> ETRF2000 -> ITRF2000 -> ITRF2014<o:p></o:p></span></li>
<li class="MsoListParagraph"
style="margin-left:0cm;mso-list:l0 level1 lfo1"><span
style="mso-fareast-language:EN-US">NAP -> ETRF2000
-> ITRF2000 -> ITRF2014<o:p></o:p></span></li>
</ul>
<p class="MsoNormal"><span style="mso-fareast-language:EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="mso-fareast-language:EN-US"
lang="EN-GB">I expected this could be achieved by changing
the Amersfoort-ETRS89 transformation to Amersfoort-ETRF2000
“instead” in EPSG. I don’t understand what advantage a
transformation to the ETRS89 datum ensemble “in addition” to
a transformation to the specific ETRF2000 realisation in
EPSG would give.
</span></p>
</div>
</blockquote>
Changing from ETRS89 to ETRF2000 could (potentially) negatively
impact workflows RDNAP to ETRS89 that behave properly currently.
Anyway you can simulate that by hacking your proj.db and modifying
the existing records or adding ones to see the effect of your
changes<br>
<blockquote type="cite"
cite="mid:AM0P192MB0482DD111B18683457FC364FEFA59@AM0P192MB0482.EURP192.PROD.OUTLOOK.COM">
<div class="WordSection1">
<p class="MsoNormal"><span style="mso-fareast-language:EN-US"
lang="EN-GB"><o:p></o:p></span></p>
<p class="MsoNormal"><span style="mso-fareast-language:EN-US"
lang="EN-GB"><o:p> </o:p></span></p>
<p class="MsoNormal"><b><span lang="EN-GB">In PROJ 9.1.1. RDNAP
to ITRF2014:<o:p></o:p></span></b></p>
<p class="MsoNormal"><span
style="font-size:10.0pt;font-family:Consolas" lang="EN-GB">echo
128410.0957 445806.4960 -0.4754 2023.00 | cs2cs epsg:7415
epsg:7912 -d 9
<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB">Gives:<o:p></o:p></span></p>
<p class="MsoNormal"><span
style="font-size:10.0pt;font-family:Consolas" lang="EN-GB">52.000004918
5.000008844 43.0018 2023.00<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB">This should be:<o:p></o:p></span></p>
<p class="MsoNormal"><span
style="font-size:10.0pt;font-family:Consolas" lang="EN-GB">52.000005512
5.000008256 43.0197 2023.00<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB">Like </span><span
style="mso-fareast-language:EN-US" lang="EN-GB">RDNAP via
ETRF2000 to ITRF2014:</span><span lang="EN-GB"><o:p></o:p></span></p>
<p class="MsoNormal"><span
style="font-size:10.0pt;font-family:Consolas;mso-fareast-language:EN-US"
lang="EN-GB">echo 128410.0957 445806.4960 -0.4754 2023.00 |
cs2cs epsg:7415 epsg:7931 -d 9 | cs2cs epsg:7931 epsg:7912
-d 9<o:p></o:p></span></p>
<p class="MsoNormal"><span style="mso-fareast-language:EN-US"
lang="EN-GB"><o:p> </o:p></span></p>
<p class="MsoNormal"><b><span lang="EN-GB">In PROJ 9.1.1. RDNAP
to WGS84:<o:p></o:p></span></b></p>
<p class="MsoNormal"><span
style="font-size:10.0pt;font-family:Consolas" lang="EN-GB">echo
128410.0957 445806.4960 -0.4754 2023.00 | cs2cs epsg:7415
epsg:4326 -d 9<o:p></o:p></span></p>
<p class="MsoNormal"><span style="mso-fareast-language:EN-US"
lang="EN-GB">Gives:
<o:p></o:p></span></p>
<p class="MsoNormal"><span
style="font-size:10.0pt;font-family:Consolas;mso-fareast-language:EN-US"
lang="EN-GB">51.999999889 5.000000153 -0.4754 2023.00<o:p></o:p></span></p>
<p class="MsoNormal"><span style="mso-fareast-language:EN-US"
lang="EN-GB">This should be:<o:p></o:p></span></p>
<p class="MsoNormal"><span
style="font-size:10.0pt;font-family:Consolas" lang="EN-GB">52.000000000
5.000000000 43.0000 2023.00<o:p></o:p></span></p>
<p class="MsoNormal"><span style="mso-fareast-language:EN-US"
lang="EN-GB">Like RDNAP via ETRF2000 to WGS84:<o:p></o:p></span></p>
<p class="MsoNormal"><span
style="font-size:10.0pt;font-family:Consolas;mso-fareast-language:EN-US"
lang="EN-GB">echo 128410.0957 445806.4960 -0.4754 2023.00 |
cs2cs epsg:7415 epsg:7931 -d 9 | cs2cs epsg:7931 epsg:4326
-d 9</span></p>
</div>
</blockquote>
<p>If you only specify EPSG:4326, the vertical transformation is not
used, so you get the following pipeline:</p>
<p>unknown id, Inverse of RD New + Amersfoort to WGS 84 (4), 1 m,
Netherlands - onshore, including Waddenzee, Dutch Wadden Islands
and 12-mile offshore coastal zone.<br>
<br>
PROJ string:<br>
+proj=pipeline<br>
+step +inv +proj=sterea +lat_0=52.1561605555556
+lon_0=5.38763888888889<br>
+k=0.9999079 +x_0=155000 +y_0=463000 +ellps=bessel<br>
+step +proj=push +v_3<br>
+step +proj=cart +ellps=bessel<br>
+step +proj=helmert +x=565.4171 +y=50.3319 +z=465.5524
+rx=0.398957388243134<br>
+ry=-0.343987817378283 +rz=1.87740163998045 +s=4.0725<br>
+convention=coordinate_frame<br>
+step +inv +proj=cart +ellps=WGS84<br>
+step +proj=pop +v_3<br>
+step +proj=unitconvert +xy_in=rad +xy_out=deg<br>
+step +proj=axisswap +order=2,1<br>
</p>
<p><br>
</p>
<p>To get a 3D transformation, you need to specify EPSG:4979 as
target:</p>
<p>unknown id, Inverse of RD New + Amersfoort to ETRS89 (9) +
Inverse of ETRS89 to NAP height (2) + ETRS89 to WGS 84 (1), 1.002
m, Netherlands - onshore, including Waddenzee, Dutch Wadden
Islands and 12-mile offshore coastal zone., at least one grid
missing<br>
<br>
PROJ string:<br>
+proj=pipeline<br>
+step +inv +proj=sterea +lat_0=52.1561605555556
+lon_0=5.38763888888889<br>
+k=0.9999079 +x_0=155000 +y_0=463000 +ellps=bessel<br>
+step +proj=hgridshift +grids=nl_nsgi_rdtrans2018.tif<br>
+step +proj=vgridshift +grids=nl_nsgi_nlgeo2018.tif
+multiplier=1<br>
+step +proj=unitconvert +xy_in=rad +xy_out=deg<br>
+step +proj=axisswap +order=2,1<br>
</p>
<p>Even<br>
</p>
<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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