The David Rumsey Georeferencer webpage is not only a phenomenal tool for mapping analysis, but it is also lots of fun. My understanding of the spatial DH projects improved as I worked through georeferencing Polynesia onto the current world map. It demonstrated an avenue to tracking humanity’s understanding of space through time. It is also fascinating to see how accurate those from older time periods were. Where were the inaccuracies? What technological setbacks may have caused this. After successfully georeferencing, I was able to change the opacity of the Polynesia map placed over the world map to observe its accuracy, and I was impressed. The Polynesia map was dated in 1894, before satellites or internet. The accuracy must be due to centuries map drafts from numerous sources. I wonder how the edges and subtle curves are exacted. It must be by comparing several detailed maps from several credible sources.
One option after rectifying a map is to add additional maps. This could be appropriate to do if you wanted to compare map accuracy/design of a certain area over time. You could also compare the map accuracy of different lands during the same time period. This could lead to an analysis of technological advancements in a certain region or a comparison of it between different regions in the same time period. The older a map is, the more difficulties it provides. People from that time period may not have understood the layout of the earth well enough to create an accurate enough earth-like map. These ideas would not apply to fictional lands as this service uses an earth map as a foundation.
The map can be used in GIS apps and can be exported as a GeoTIFF file. It can be viewed in additional formats such as WMTS, TileJSON, or XYZ formats.