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I am trying to georeference some old mining maps (Floetzkarte des Oberschlesische) in QGIS 2.9. I have already tried to do that by marking known points on present satelite photos, but the results were poor. Then I used some other old, but already georeferenced maps (Messtischblatt) and marked triangulation points present on both maps. Georeference based on these points was quite good, but unfortunately I noticed that not all Messtischblatt contain traingulation points at all, so this method doesn't work for all maps.

The maps use some strange coordinate systems, totally incomprehensible for me. The reference point (null point) which is located at sheet no. 3 (TPL at the picture), seems to be located at (491138, 282639) EPSG:2180, (18.8752414523, 50.4108051983) WGS84.

Reference point

Each Floatzkarte's sheet contains coordinates in meters relative to this null point. The coordinates are in corners of the maps as well as on its borders.

enter image description here

Could you provide me with some information about the CRS used on these maps and/or instruction on how to prepare proper proj4 parameters for it, so that I could use that in georeferencing process?

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If those "strange" coordinates do not fit to Gauss-Krueger coordinate systems, they might be similar to the "preußisches Koordinatensystem". You will find some links to that in my answer to

Conversion of coordinates of "Bochum coordinate system"

You have to put up a custom CRS on the point "Trockenberg" in Cassini-Soldner projection, which was common at that time:

+proj=cass +lat_0=50.4108051983 +lon_0=18.8752414523 +k=1 +x_0=0 +y_0=0 +ellps=bessel +towgs84=0,0,0,0,0,0,0 +units=m +no_defs
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  • Thank you for your help, I applied little changes to your CRS and It seems to work: +proj=cass +lat_0=50.4108051983 +lon_0=18.8752414523 +k=1 +x_0=-0.014 +y_0=65.338 +ellps=bessel +towgs84=0,0,0,0,0,0,0 +units=m +no_defs +axis=wsu Apr 9, 2015 at 12:35

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