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Comparing the true size and shape of geographically distant features

Question asked by tomburj on Jun 8, 2020
Latest reply on Jun 10, 2020 by GSCUser85

Apologies in advance if this is a dumb question or I'm missing something obvious... It's rare I have to leave the confines of the Ordnance Survey National Grid and think about reference systems. 


I saw this image on social media and thought it would be fun to experiment with. I obtained shapefiles for Australia and the Mediterranean sea, they used different CRSs so I projected them to a common world one (web mercator to start) and simply dragged the Mediterranean over Australia in edit mode to compare and visualise. This worked fine, but I was concerned that distortion in web mercator would make the comparison invalid. 


For the comparison, distance and direction doesn't matter since the features will be moved to an arbitrary location, but shape and area needs to be accurate. Since a projection can't conserve both I toyed with some compromise projections, but most seem to distort either Aus or the Med quite heavily. 


I guess this image is closest to what I'm imagining I need, size and shape conserved even if the features are not in their true location. Possibly drawing both using locally suited reference systems, then bringing one into the other's system without actually changing any of the geometry? I'm not sure if that even makes sense. 


Perhaps I'm getting too hung up on projections and need to work with a geographic reference system. But I'd still need a way to visualize it accurately. 


I've been using ArcMap 10 while messing around with this, but also have access to ArcGIS Pro if needed. 


Many thanks in advance!