Q: Why cannot I overlay a vector dataset and a raster dataset correctly in SuperMap even though they can overlay well in ArcGIS? They are both in WGS84, and after been imported into SuperMap, the vector dataset displays correctly but the raster dataset display wrongly. Why does this happen?
A: The reason that the vector dataset and the raster dataset cannot overlay correctly is that the projections of the two datasets are not identical. In ArcGIS, projection transformation on the fly is automatically used. However, in SuperMap, you need to set by yourself. The suggested method is as follows: Create a datasource with projected coordinate system (such as Gauss–Krüger coordinate system)—A, import the raster dataset, and currently the coordinate information is correct. Then, create a datasource B with longitude and latitude coordinate system, import the vector dataset, and the coordinate information is correct. After that, transform the projection of B to that of A, and copy the data in the vector dataset to A. Now you can display A and B with vector data and raster data appropriately.