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Nyall,
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<div class="">This is basically the same question as you asked a few months ago:</div>
<div class=""><a href="https://lists.osgeo.org/pipermail/proj/2019-March/008390.html" class="">https://lists.osgeo.org/pipermail/proj/2019-March/008390.html</a></div>
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<div class="">Not sure exactly what celestial body you are trying to map this time,</div>
<div class="">but the problem remains the same: WGS84 is a CRS belonging to Earth,</div>
<div class="">that can’t meaningfully be transformed to a CRS on another</div>
<div class="">planet/moon/asteroid/whatever.</div>
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<div class="">You can convert between different ellipsoids but does it make sense when one</div>
<div class="">has a radius 3 times larger than the other? Anyway, here’s how:</div>
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<div class="">echo 12 56 0 0 | cct +proj=pipeline +step +proj=cart +ellps=WGS84 +step +proj=cart +R=2632345 +inv</div>
<div class="">12.0000000000 55.8213634673 3731132.8860 0.0000</div>
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<div class="">Notice the height of the original point flying 3700 km above the ground on</div>
<div class="">the new ellipsoid.</div>
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<div>Can you explain in which scenarios you need to do the transformation</div>
<div>you are asking for? That might make it easier to advise you.</div>
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<div>/Kristian</div>
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<blockquote type="cite" class="">
<div class="">On 20 May 2019, at 05:15, Nyall Dawson <<a href="mailto:nyall.dawson@gmail.com" class="">nyall.dawson@gmail.com</a>> wrote:</div>
<br class="Apple-interchange-newline">
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<div class="">Hey list,<br class="">
<br class="">
If I attempt to create a transform using proj_create_crs_to_crs, with<br class="">
the source proj string "+proj=longlat +datum=WGS84 +no_defs" and dest<br class="">
proj string "+proj=longlat +a=2632345 +no_defs", I get the error<br class="">
"internal_proj_create_operations: Source and target ellipsoid do not<br class="">
belong to the same celestial body".<br class="">
<br class="">
My question is -- should this be allowed? It worked ok in previous<br class="">
proj versions, and it's a common situation in QGIS which I'm having<br class="">
issues fixing after the v6 port.<br class="">
<br class="">
Or is it violating some rule of transformation? How can I reproduce<br class="">
the proj 4 behaviour here?<br class="">
<br class="">
Cheers,<br class="">
Nyall<br class="">
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