Projections

Most GIS Software doesn't have a built-in map projection for Middle Earth, or Pern, or any other fictional world that we want to create a map for.  But they do give us some good tools to create one.  The first thing to consider is how big is the world you want to map.  Is is the size of Earth - that makes it really easy, just use an Earth projection.  More likely it is a little smaller.  I find a lot of authors when they come up with their own maps of their worlds don't want to create such a large space that they have trouble filling it all, so they tend to go smaller.  In tools like ArcGIS or QGIS they have predefined coordinate systems available for all of the planets and moons in our solar system.  A good starting point is Mars which is about half the size of Earth.  You can copy the coordinate system and rename it.  Creating a new Datum and Projection are pretty challenging tasks and could potentially involve a lot of math, so I'd personally suggest you stick to the predefined choices.  Here are the radii in kilometres of your most likely candidates:

Neptune	24622±19
Earth	6371.0±0.01
Venus	6051.8±1.0
Mars	3389.5±0.2
Ganymede	2634.1±0.3
Titan	2576±2
Mercury	2439.7±1.0

If you do want to create your own datum, that can be done too.  I've selected a custom projection and decided to make a world halfway between Mars and Earth in size, at around 4500 km radius:

You will probably want a Projected Coordinate system for making maps, as well as your new Geographic Coordinate System so you can create one of those too.  This one may take a little experimentation to get it to appear the way you want to once you have some data created.

That's all for today - next time we'll start creating data.

Welcome

GIS or Geographic Information Systems is a tool used to create detailed maps of the world we live in, whether large areas or small.  But very rarely does that tool get applied to fictional places.  Most maps that you see inside to cover of a novel, or in the background of the credits of a movie, are either made with traditional paper and pen methods, or are made in illustrator and photoshop.  This is all well and good when you simply want a visual that will never change, but in this era of fan created wiki pages for the great works of fiction, sometimes fans want more.  How about a web-based map that shows the journeys of all the principal characters.  Or a map you can zoom in on to see greater detail.  Working from the map inside the cover of a novel, you can give the world it's rudimentary shape, and then start fleshing out the detail.  Ideally you'd like to be able to work with the author, to hold to their vision of the world they created, but as that isn't always possible, just think of the enhanced map as a work of fan fiction, much like a fan who writes an extra chapter or novella to fill in back story.  As I write this blog, I will share with you my insights into how to create the essentials for fictional worlds - picking fonts and symbols, projection systems, base map layers, adding detail, and improvising what isn't known.  I'll be doing all this while I work on a GIS system for one of my favourite fictional worlds, for the Wheel of Time series by Robert Jordan.