So, the situation involves :
- QGIS 2.18 and georerencer plugin;
- Downloaded TIF of an old canadian topographical map from Quebec National Library and Archives (permalink here) and as you can see, this nice map included a grid with latitude and longitude.
- The project I'm working on includes vector data using NAD83 MTM7.
Now, the problem :
- Right after selecting file in the georeferencer plugin, I have to enter what i think is the CRS of the original map, which I don't have a lot of info on (It says "polyconic projection" only).
- I was under the impression that "real" lat/long would be more than enough to georeference it precisely, but it appears that a entering a CRS is essential!
Now, the questions are :
- Is there any way I can avoid specifying a CRS when using georeferencer and just enter the lat long of the grid corner? Something that would tell QGIS "Look, forget the CRS, I have latitude and longitude and that all you need!"
- If answer to question 1 is "No", what should I do?