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data acquisition - Does GeoGraphics support Elliptical Mercator projection?


When working on the answer to this question I found that GeoGraphics seemingly uses by default the Spherical Mercator projection (also known as "Web Mercator") which is used by such geoservices as Google Maps, OpenStreetMap and Wikimapia:



EPSG:3857 - WGS 84 / Pseudo-Mercator (Spherical Mercator, Mercator on Sphere)



Unlike them such geoservices as Yandex Maps and Kosmosnimki.ru use the Elliptical Mercator projection:



EPSG:3395 - WGS 84 / World Mercator (Elliptical Mercator, Mercator on Spheroid)




Is it possible to work in the Elliptical Mercator projection with GeoGraphics?


P.S. NGA Advisory Notice on "Web Mercator".



Answer



Yes, it is possible to use the ellipsoidal Mercator projection by specifying an ellipsoidal "ReferenceModel" in the projection.


To compare, let me define a spherical Mercator projection:


In[1]:= webMercator = {"Mercator", "ReferenceModel" -> GeodesyData["ITRF00", "SemimajorAxis"]}
Out[1]= {"Mercator", "ReferenceModel" -> Quantity[6.37814*10^6, "Meters"]}

and then an ellipsoidal Mercator projection:



In[2]:= ellipMercator = {"Mercator", "ReferenceModel" -> "ITRF00"}
Out[2]= {"Mercator", "ReferenceModel" -> "ITRF00"}

We can create the respective maps:


In[3]:= webmap = GeoGraphics[{FaceForm[], EdgeForm[Red], Polygon[{Entity["Country", "UnitedKingdom"], Entity["Country", "Ireland"]}]}, GeoProjection -> webMercator, GeoBackground -> None];

In[4]:= ellipmap = GeoGraphics[{FaceForm[], EdgeForm[Blue], Polygon[{Entity["Country", "UnitedKingdom"], Entity["Country", "Ireland"]}]}, GeoProjection -> ellipMercator, GeoBackground -> None];

Finally we display them together, to show the difference between using the projections:


In[5]:= Show[webmap[[1]], ellipmap[[1]]]


enter image description here


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