Defining projection and coordinates of Ukrainian topographic map

Question

I managed to get Ukrainian topographic map

I'd like to do the georeferencing in QGIS.

The problem is that I don't have a clue which projection was used and how to read the 'X' and 'Y' coordinates in those maps. I don't know Ukrainian either.

Answer 1

Coordinate reference System

@razi you should have a look at www.epsg.io and search for coordinate reference systems of Ukraine there.

However, the most recent GCS is UCS-2000 see this site for details: http://epsg.io/5561

Gauss Kruger Projections (e.g. http://epsg.io/5562) and Transverse Mercater projections (TM Zones) (e.g. http://epsg.io/6383) are used for projecting this GCS.

In the bottom left of the image is the date 1979. If this is the date of publication then I'd suspect the geodetic datum used would be Pulkovo 1942 and projected into a Gauss Kruger Zone perhaps number 6.

Map Location (georeferencing start)

I had a look at the placenames in the image and one town is called При́п'ять (Pripyat - a town of regional significance in Kiev region) you can find it in Google Maps and it shows up in this area which is where you should georeference your image to. Of note is the prescence of Chornobyl (Чорнобиль) to the southeast of При́п'ять its neighbouring lake hosting the next crossing of the Pryp'yat' river.

Answer 2

If you carefully look at your composite zona.jpg, you see that the main eastern coordinates have a gap at the 30° meridian, and the latitudes have a sharp bend there. There is a secondary coordinate line on the top, that follows the western CRS on the eastern part, and the eastern CRS on the western. Same for the latitudes.

The EPSG definitions of 3-degree Gauss-Krueger have central meridians at 24/27/30/33°, but the imprinted CRS does not fit to these: You would have the false Easting of 500000 (EPSG:2585) or 10500000 (EPSG:2526) at 30°, but instead you have a gap there.

Instead , the 6-degree Gauss-Krueger CRS fit better for the western and eastern half:

Pulkovo 1942 / Gauss-Kruger zone 5 : +proj=tmerc +lat_0=0 +lon_0=27 +k=1 +x_0=5500000 +y_0=0 +ellps=krass +towgs84=23.92,-141.27,-80.9,-0,0.35,0.82,-0.12 +units=m +no_defs
Pulkovo 1942 / Gauss-Kruger zone 6 : +proj=tmerc +lat_0=0 +lon_0=33 +k=1 +x_0=6500000 +y_0=0 +ellps=krass +towgs84=23.92,-141.27,-80.9,-0,0.35,0.82,-0.12 +units=m +no_defs

This seems to be similar to UTM or EPSG:28465/28466, except for the leading zone number.

So you can georeference your single maps to the respective zone CRS, and reproject one half to the CRS of the other in a second step. Or use the inner coordinates for one half, and the outer coordinates for the other.

Georeferencing by using the degree coordinates as EPSG:4284 (Pulkovo 1942) is another option, but might invoke some disturbances, since the map is projected to meters, not degrees.