This script was created for a colleague. The main scrip (tif2png) refers to the others. It begins with making the other scripts executable. Then it downloads and it asks if you'd like to download the files, the user will answer with any combination of yes or no and if the response is yes it will navigate to a website download files and then unzip them. It will then start rasterize and conversion of the files by utilizing the two remaing scripts (gdalrasterize and gdalwarp).