Many thanks Keith, putting control points on the intersections is a great idea. I'll give that a try.
Clay On Dec 7, 2007, at 11:25 AM, Keith Jenkins wrote:
Hi, Clay. Your details are daunting, but I'll try to help :) Since your map is lucky enough to have them, I'd suggest using the intersections of the latitude/longitude lines as your control points. Besides offering nice round numbers, they are evenly spaced across the map. Try it first with every 10 degrees, and if that isn't good enough, go with every 5 degrees. The projection of the original map is not so important in this process, since you are using control points. And the datum really doesn't matter here: the difference between WGS84 and NAD83 is going to be less than the width of the lines on a map of this scale. So I wouldn't worry too much about the map having been folded, either. As for relying on open source tools, you should be in good hands with GDAL, GeoServer, and OpenLayers. Good luck! Keith
