One way would be to use G Projector (comes up easily in a web search). If your equirectangular projection is already colored as a satellite view, you can import it as a .bmp file and choose from several different projections. There is a size limit, however, and the output may not be of the highest quality dep ending on how large you try to make it. Optionally, if you have Fractal Terrains, you can use Wilbur to set up a dem file that can be imported. Waldronate can tell you more about that option if he swings through.

Hope that helps some.