I have a shapefile of European states (open-access from here: http://tapiquen-sig.jimdo.com) and DEM data downloaded from Copernicus.
- Europe states vector is in GCS_WGS_1984
- if projected to ETRS89_ETRS_LAEA datum: D_ETRS_1989)
- Europe DEM tiles (raster) are in ETRS89_ETRS_LAEA (Datum: D_ETRS_1989)
(ArcGIS on-the-fly reprojection)
but when I zoom in, I see there is a shift of ~200-400 m (I have not noticed any trend going for example south to north, i.e. increasing or decreasing discrepancy).
Is it my raster, or vector data which is not correctly aligned?
Datums in reprojected data looks the same: D_ETRS_1989
I have plotted the basemap layer, and it seems that my raster (DEM, ETRS89_ETRS_LAEA) is better aligned with satelite imagery basemap.
Here is output using Effect tool, DEM is black. When transparent, it is obvious that aligns to basemap better that vector shp (red).
The reprojection of Europe shp from WGS84 to ETRS89 did not help, neither to open reprojected vector in a new dataframe.
How do I "objectively" assure that vector and raster data will align in all the time? (without for example manual shift?)
My fear is, that I can spot that raster and vector data do not align due to shore and islands edge effect. But what if I will have the same shift in my WGS84 GPS point data, and I will just overlook it because I have now way to verify where the data come from?