Martijn van Oosterhout wrote: > [SRTM] > Someone pointed out to me yesterday that there is a program > gdal_contour which does this. Indeed. There's another one called dem2topo but you have to install a scary IDL virtual machine for that. http://www.gdal.org/gdal_contour.html http://people.uleth.ca/~brad.gom/dem2topo/ cheers Richard