I have a world file and it was used to locate my raster after setting the SRS, but when I check the coordinate information, it says "unknown spatial reference", also when I tried set SRS again it still lists the raster as having an unknown spatial reference. Do I have to define projection or georeference again?
Set ArcGIS to read the world file first
If it is a valid world file, it will read it. As a last resort, you can try Define Projection
It is valid and has been read. However I wanted to know if I can go ahead and digitize my features on this basemap even though I complains of last of coordinate system. Is it more appropriate to go ahead and define projection?