This weekend, my publisher forwarded me a nice email from Jim Bosch, a reader of my book, GPS Mapping – Make Your Own Maps (Amazon). Jim has some great tips about free software that makes creating your own GPS maps even easier, and I’m including his entire email below, verbatim. I especially liked learning about a tool that directly converts SDTS files to shapefiles, eliminating one of the steps in the process that I described in Chapter 24. Thanks Jim!
I learned a lot about creating custom topographic maps from Rich Owings "Make Your Own Maps", but I have found a few more software gems on my own that I feel fill a lot of the remaining "holes" in his instructions for a complete, FREE solution for custom maps:
The first is OGR (http://www.gdal.org/ogr/). It’s a free programming library (and, more importantly, a command line tool called "ogr2ogr") that allows for conversion between virtually any vector GIS format, including a direct method to from SDTS to ESRI shapefiles. You can even change projections and run filters on the data when converting. The above link includes packages designed mostly for Linux users or Windows programmers, but an easy-to-install Windows package that also includes a decent free map viewer program is available at http://fwtools.maptools.org/
There’s actually an even better free viewer at http://qgis.org/ – the latest version has functionality approaching that of ArcMap.
One last thing: I’ve also discovered that the Canadian government has free shapefile downloads (http://geogratis.cgdi.gc.ca/geogratis/en/index.html) for its topographic data, which is of course a lot easier than fiddling with SDTS if one wants to make maps of Canada.
Thanks for an excellent book that inspired me to look for these things, and please help me share them with your other readers!