Desktop GIS - the book

The Generic Mapping Tools (GMT) can be used to create high quality maps for printing or use in web pages or documents.

You can easily create a simple globe (similar to the one on this website) using GMT. Here is the command:

pscoast -JA0/20/2.5i -Bg30/g15 -Dl -A2000 -G187/142/46 -S109/202/255 \ 
  -R0/360/-90/90 -P -N1 > simple_hemi.eps

This produces:

Sometimes you need just a portion of a raster for use in your latest mapping project. In this example we will see a simple way to extract a rectangular region of an image and warp it to the desired projection.

The tools for accomplishing this feat are gdal_translate and gdalwarp, both part of the GDAL suite of utilities. On Linux and Windows you can easily get access to these tools by installing FWTools. If you use a Mac, download the GDAL framework and required dependencies from Kyng Chaos.

The Pragmatic Programmers have announced the upcoming Desktop GIS title.

The U.S. Geological Survey has an excellent poster on projections available at http://erg.usgs.gov/isb/pubs/MapProjections/projections.pdf. You can also download it from this site.

Sample Data

The sample data for Desktop GIS includes world boundaries, cities, and a global mosaic.

• Download World Boundaries and Cities (3.3 Mb, Shapefiles)
• Download World Mosaic (31 Mb, TIFF)
• Bird Data from Chapter 3
  

Additional Sources

• http://data.freemap.in - OSGeo Geodata repository
• http://geotorrent.org - Blue Marble and World Landsat
• http://freegis.org - list of free data sources