magnetoreo.blogg.se - Point and click map

Select the Add point tool and click in the intersection of the cross-hairs (pan and zoom as needed).You will use this point as the first ground control point for the georeferencing your map. Zoom in to the left lower corner of the map and note that there is a cross-hair with a coordinate pair, x and y, that as mentioned before are in KKJ / Finland zone 2 CRS.You can use the zooming and panning tools as you usually do in QGIS to inspect the image in the Georeferencer’s window. The map contains several cross-hairs marking the coordinates in the map, we will use those to georeferenciate this image. Set the rest of parameters as shown below.Click the icon next to the Output raster box, go to the folder and create the folder exercise_data\forestry\digitizing and name the file as rautjarvi_georef.tif.Open Settings ‣ Transformation settings.Next you should define the transformation settings for georeferencing the map:

When prompted find and select the KKJ / Finland zone 2 CRS, it is the CRS that was used in Finland back in 1994 when this map was created.

Add the map image file, rautjarvi_map.tif, as the image to georeferenciate, File ‣ Open raster.

Open the georeference tool, Raster ‣ Georeferencer ‣ Georeferencer.

Activate the plugin using the plugin manager as you have done in previous modules. You will use the georeferencing plugin from QGIS, the plugin is already installed in QGIS. Save the QGIS project as map_digitizing.qgs. Make sure that Enable ‘on the fly’ CRS transformation is checked, since we will be working with old data that is another CRS.

Open QGIS and set the project’s CRS to ETRS89 / ETRS-TM35FIN in Project ‣ Project Properties ‣ CRS, which is the currently used CRS in Finland. Follow Along: Georeferencing the scanned map ¶