Making an Alternate Earth Google Earth Overlay

[Coriolis]

I've got a project that I've been wanting to do for a while, but I'm having some trouble getting started.

Problem: I need to find a monochrome (land white, oceans/lakes black, or vice-versa) real-world Earth map projection that I can overlay onto Google Earth for a precise fit.

Purpose/background: I'm trying to create a world map for the Rifts RPG, a post-apocalyptic future Earth in which sea levels have risen and a new continent, Atlantis, has appeared. Coastlines have changed, but the locations of major features are the same. My plan is to make this as a vector map with as much detail as I can find in the many Rifts RPG books. This vector world map could then serve as a single, consistent baseline from which to create high-quality detailed regional maps, either by zooming in on the flat projection or by overlaying this vector map on Google Earth and taking a high-altitude image of the region of interest. This could also be useful for creating some virtual globes of Rifts Earth for some artistic planetary images, but that would be more of a "down the road" follow-on project.

The project plan:
1. Find a monochrome world map projection that can map precisely onto Google Earth.
2. Vectorize the projection (Inkscape has a nice tracing function for this).
3. Adjust the vector map to conform to the published Rifts canon maps.
4. Profit!

Now I can find plenty of monochrome Earth projections, but none of them seem to be a good fit for Google Earth when I overlay them. The best ones develop a pronounced offset such that either the regions outside the tropics are a good fit, or the regions inside the tropics are a good fit. I can't find one that does both. Any ideas?

[Hai-Etlik]

Google uses a wonky projection that assumes that the Earth is a perfect sphere while it is more typically modelled as an oblate spheroid (still not exactly right but much closer) this underlying idea of the shape of the Earth used by a projection is called the "datum" (The plural is "datums" rather than "data" in this particular case).

It sounds like your best option might be to use a GIS and proper spatial vector data rather than a vector graphics toolset, at least for geometry editing and projection. QuantumGIS and Natural Earth respectively for instance. Natural earth is already vectorized and includes various other real world data besides coastlines. QGIS has tools specifically for the kind of editing needed for this like topology preserving editing of boundaries (if you edit the border of two countries, both countries should be changed). It can also reproject the information while keeping it in vector form, including appropriate projections for regions (just zooming in on a world map doesn't work) and the special spherical forms used by Google, OSM, etc.

[johnvanvliet]

I need to find a monochrome (land white, oceans/lakes black, or vice-versa) real-world Earth map

that is easy
NASA's BlueMarble2
the Arctic regional mirror
ftp://mirrors.arsc.edu/nasa/

the Landmask
ftp://mirrors.arsc.edu/nasa/landmask/
is the water MASK
a small 5400x2700 map ( yes that IS small )
ftp://mirrors.arsc.edu/nasa/landmask....5400x2700.png

OCEAN ONLY!!!! mask
ftp://mirrors.arsc.edu/nasa/landmask....5400x2700.png

and READ!!! the README file!!!
-- PDF - warning
ftp://mirrors.arsc.edu/nasa/landmask/readme.pdf

a post-apocalyptic future Earth in which sea levels have risen and a new continent, Atlantis, has appeared. Coastlines have changed, but the locations of major features are the same

For THAT the above land or water masks are well useless !

you need the topography PLUS!!! the bathymetry
ftp://mirrors.arsc.edu/nasa/topography
-- low res small jpeg
-- under water ONLY in the jpg images
ftp://mirrors.arsc.edu/nasa/topograp....5400x2700.jpg

land AND water in the raw image below
and create your OWN mask using the 16 bit SIGNED( lsb) integer data
ftp://mirrors.arsc.edu/nasa/topograp...1x10801.bin.gz

My plan is to make this as a vector map with as much detail as I can find in the many Rifts RPG books.

easy to do a ok svg using inkscape using trace bitmap

Qgis would be a bit of a better option then google earth

or a image editor that can use 16 bit signed data ( and 32 bit float )
and use the bluemarble files i posted