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I have a list of neighbourhood polygons in Casablanca, Morocco, which have an unknown CRS. Here is a link to one of the polygons: (link to a json).

I have tried several CRS in QGIS, but none of them seem to match. The origin (0,0) of the polygons appears to be located near Casablanca, which suggests that it might be a custom projection system used to render a map in some web app. screenshot of the polygons

I have also tried to find a transformation system using 3 points that I can pinpoint on the map (I identified these points from the shape of the polygons). However, I am not sure how to use them.

mapX,mapY,sourceX,sourceY,enable,dX,dY,residual
-7.66019156489551012,33.60254389161183752,13818.32712767139673815,-10907.70249749449430965,1,-0.00005545246380123,-0.00002593604340717,0.00006121808629192

-7.65505437867152239,33.59849756468478432,14799.86116917156505224,-11801.17367171987825714,1,0.00005835360482909,0.000031161882319,0.00006615289945431


-7.55462555909517963,33.57873525323550723,33560.92118483640660997,-16235.50596761874476215,1,-0.00000290114103052,-0.00000522583923868,0.00000597712431086

Can anyone suggest a method or tool to properly georeference these polygons?

PolyGeo
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Karim
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  • Check this out, may be helpful: https://gis.stackexchange.com/questions/51868/rubbersheeting-of-vector-layers-in-qgis – Jeffrey Kaplan Apr 24 '23 at 15:19
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    @JeffreyKaplan, nice suggestion, and since QGIS 3.28 it is native functionality. Layer > Georeferencer > File > Open Vector. – Matt Apr 24 '23 at 15:30
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    Thank you @JeffreyKaplan and @ Matt. I updated QGIS and this works perfectly. – Karim Apr 25 '23 at 08:18

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