I have many sets of ungeoreferenced scanned historical aerials for various years that cover the same geographic area. There are always overlaps between adjacent frames for any given year. I want to mosaic and georeference them so that they can be aligned and overlaid with more recent aerial photography. The workflow that I was thinking of was to mosaic all the ungeoreferenced frames for a given year first and then georeference the one mosaicked file. Is this the best workflow to proceed with? I was thinking that the 'pixel based mosaic' tool would be the one to use for this. That being said, I have tried several times to line up the features from various neighboring frames but am unable to do so since I can't zoom in on the 'pixel based mosaic' widget to see exactly where two frames overlap? Am I missing something here or is there a better way to do this? I don't get the coordinate x0 and y0 thing and all that. I just want o visually place one on top of the other where the same features overlap. Also, I have a georeferenced contemporary image that I want to register everything to. I assume using the 'Registration: Image to Image' tool is what I want but am not sure. Can anyone provide help with the workflow or suggestions? Thanks