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.shp with unknown coordinate system

I need to capture spatial information off of an old map and I can't determine the coordinate system of the image. I also need to examine/cross-reference some information via overlay. The subject area is Kirkland Lake Ontario, the scale of the map is 1 inch to 400 feet, and an example of the coordinates shown is 86,000E - 90,000N (on the southwest corner of the map).

I took a few guesses at the coordinate system (as did my co-worker) and we haven't had any success. We figured it might be something of the old NAD27 variety. I also tried using the road, rail, utility line and river layers from the province to georeference the old map, but I'm not having good results that way either. Accuracy is preferred too, so using the grid to georeference this map would be the preferred method. I fear this map may have been generated with some sort of custom coordinate sytem that the local mining companies were using many decades ago.

Any ideas?


2 Answers 2


I came across something rather similar. That is a mine grid that the company uses. As far as I could tell, it does not line up well with any co-ordinate system out there. I think it is based in NAD 83, but I am not sure. The way we figured it out was to talk to the mine itself. Good luck


Below is a link to a previous post that has various stratigies (from the GIS SE community) to help figure out an unknown coordinate system. The question below is for a vector layer but the idea is the same for a raster layer.

.Shp With Unknown Coordinate System

  • @art Good call. The questions are identical.
    – whuber
    Jun 8, 2011 at 15:15
  • ok .... following this particular thread .... I tried forcing the raster to align using government data in both NAD 27 & 83. ArcMap could not stretch the image anywhere near to an acceptable degree of accuracy. As for the coordinates shown on the grid, I have no idea what coordinate system to even attempt to try. Do you guys think rubbersheeting in CAD might yeild better results? (also -+1 @ art).
    – Dano
    Jun 8, 2011 at 15:27
  • It might, but you could always try the client. We had a very similar project, and the client told us exactly how to reference it. I think it is a custom co-ordinate system.
    – Andrew
    Jun 8, 2011 at 15:47
  • 1
    There appears to be enough features (buildings, water bodies, roads, rail) on the screen capture. You should not have any trouble georefereincing this. (you will probably need to rotate it first) Judging by the image you can't really expect any great accuracy here. Jun 8, 2011 at 16:02
  • 1
    Agreed with Jakub. There is enough detail in the area to georef. to, provided that the data you are using to georeference to is of good enough quality for the area.
    – Andrew
    Jun 8, 2011 at 17:02

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