# Is there a coordinate system specifically designed for oblique map viewing?

I've long been impressed with maps that have an oblique perspective that also provides the viewer with a sense of the earth's curvature. National Geographic maps for decades often have had this type of view, wherein scale varies as the earth recedes into the distance. Similarly, here's a 2013 example from the New York Times:

I get the sense that I'm looking down from a spaceship. Google Earth gives a similar impression:

All of my previous mapping has used a traditional vertical view, so I thought that I would expand my cartographic skills by learning how to create that "oblique, bulging-earth effect" with Arc Desktop, using the New York Times map above as a reference.

I couldn't find any advice on how to proceed, so I experimented with a variety of coordinate systems. the best that I came up with was the Vertical Perspective (World) (ESRI also refers to it as the World Vertical Perspective):

(For this example I modified the Longitude of Center to -150.0 to give the map the off-center, angled view towards the northeast.)

I think that this is not too bad. I included latitude and longitude lines to confirm that the image indeed curved and bulged.

This was an interesting process which helped me to see how a variety of coordinate systems (and their settings) affected the map.

Now that I've found something that appears to work I'm wondering... are there any coordinate systems specifically designed to create the "oblique, bulging-earth effect" that I'm looking for?

It occurs to me that there may be some who object to my use of the phrase "Coordinate System", preferring that I use "Spatial Reference" or something else. To fend off such diversions, I am merely following ESRI's nomenclature, as pictured below.

• I don't think any projections are designed with that in mind. This "oblique, bulging-earth effect" you describe is because - and this may come as a shock to you - the earth is spherical! Any perspective projection (orthographic, isometric) will do this. – Spacedman Feb 20 '18 at 8:28
• You say the earth is round? Well, I dunno... economist.com/blogs/graphicdetail/2017/11/daily-chart-21 – Stu Smith Feb 20 '18 at 16:22
• I think you're looking for a tilted or oblique perspective projection. We don't have it in ArcGIS yet. As you've found, vertical near-side perspective, orthographic, or possibly the new geostationary satellite projection (10.6). – mkennedy Feb 20 '18 at 18:21
• Interestingly, the World_Vertical_Perspective coordinate system that I used has as part of its description "Height: 35800000.0". This value converts to 22,245 miles, which is darned close to the 22,236 miles that Wikipedia states as the altitude for geosynchronous satellites! – Stu Smith Feb 21 '18 at 1:04