I have multiple historical aerial photographs that I would like to use to compare coastal change over time in relation to urban development. The aerials I have obtained come in tiles that are not georeferenced but they are also not big enough to get a good RMSE when georeferencing them individually. So to fix this I would like to turn each of the individual tiles into one large mosaic to use for georeferencing. However, when adding them into Arcmap they each just layer on top of each other which does not help me at all. Is there anyway that I can manually (or otherwise) arrange them into their correct order so that I can then combine them into a single mosaic and subsequently accurately georeference?
You can use Photomerge if you have overlap in your rasters.
Images should overlap by approximately 40%. If the overlap is less, Photomerge may not be able to automatically assemble the panorama. However, keep in mind that the images shouldn’t overlap too much. If images overlap by 70% or more, Photomerge may not be able to blend the images.
If Photomerge does not work for you, try a manual overlap/blend/stitch.
After this you can simply georeference the raster. Use an online service, find good points for the corners and add extra points for the coastal area for an increase in precision in that area.