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<div class="moz-cite-prefix">On 2018-09-21 23:22, Martin
Koppenhoefer wrote:<br>
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<blockquote type="cite"
cite="mid:E1DADC22-B43C-4B10-B66B-888CF6EEA63D@gmail.com"><br>
<div id="AppleMailSignature">sent from a phone</div>
<div><br>
On 21. Sep 2018, at 21:32, André Pirard <<a
href="mailto:A.Pirard.Papou@gmail.com" moz-do-not-send="true">A.Pirard.Papou@gmail.com</a>>
wrote:<br>
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<div align="left">The whole cadastral map is offset by that
7m.<br>
...</div>
<br>
<div align="left"><b>Picture 3:</b> So, I dragged his parcel
right onto the wall.<br>
And now it's correctly located, aligned with the fencing all
around.</div>
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<div><br>
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how did you know which source was off, the cadastral map or the
orthophoto?</blockquote>
The ortophoto is guaranteed with a 20 cm precision all over
Wallonia.<br>
On the other hand, all aerial photos cannot be off by the same 7m
could they?<br>
On the first foot, juxtaposing precisely measured parcels produces
huge errors that vary all over a village.<br>
I just can't figure.<br>
I did not check if this occurs at gaps when crossing roads or what.<br>
I'm not working for the Cadastre. I pay them <span
class="moz-smiley-s3"><span>;-)</span></span><br>
<br>
In Beijing, it was Google Maps that moved.<br>
Satellites (several if I recall) were showing OSM in the right
place.<br>
<br>
All the best,
<br>
<br>
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<td>André.</td>
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<blockquote type="cite"
cite="mid:E1DADC22-B43C-4B10-B66B-888CF6EEA63D@gmail.com">
<div>
<blockquote type="cite">
<div align="left"> </div>
<div align="left">...</div>
<div align="left"> <br>
The Belgian cadastre is not the only one with an error
shift.<br>
With JOSM, I have similarly proved that Google Map has a
120m NE shift in Beijing.<br>
Nobody noticed it. </div>
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<div><br>
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<div>it is well known that the chinese government requires all
imagery and map providers to use chinese algorithms which
distort the map coordinates systematically, in a way that they
remain usable as long as your navigation system uses the same
algorithms.</div>
<div><br>
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<div>Ciao, Martin </div>
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