How do I import and project TIFF files that have no projection or associated world files?
With Global Mapper v5.0 and above, you can rectify (georeference) any TIFF imagery, regardless of whether it has a world file. If you try to load a TIFF with no positioning information, you will be prompted to rectify the image. You can also use the File->Rectify (Georeference) Imagery menu command to force the image to be rectified.