[GIS] Wrong scale when importing dxf into QGIS

dxfqgis

Has anyone had the problem that the scale of the shp layer converted originally from a .dxf file turns out to be wrong?

For example, I draw a line of 10 meters long in AutoCAD and imported it in QGIS, however the length of this line turns out to be several thousand kilometres.

Best Answer

Google satellite (EPSG:3857) is not a good idea. The units are metres, but only at the equator. The more to the North you go, the greater the difference gets.

Alternatively, you can use a custom CRS in transverse mercator projection, with latitude and longitude of origin (in degrees) at the point where your dxf file has its origin:

+proj=tmerc +lat_0=... +lon_0=... +x_0=0 +y_0=0 +k=1 +ellps=WGS84 +towgs84=0,0,0,0,0,0,0 +units=m +no_defs
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