Sample Dataset – World Map

December 9th, 2007

A number of our posts have covered downloading and using GIS data but it should be more beneficial to readers if a single post contained all the instructions needed to acquire the data layers in each dataset. Our first such dataset, named “World Map”, has already been introduced but will be discussed in more depth here for the sake of new readers.

CGI MapServer Map

Dataset Details

  • Number of data layers: 2
  • Map Projection: Geographic (see Equirectangular projection)
  • Map Units: Decimal degrees
  • Map Extent(min x, min y, max x, max y): -180 -90 180 90

Layer 1: Countries Shapefile

The first layer in this dataset is a polygon shapefile containing world countries.

Countries Shapefile

Source: http://www.cipotato.org/diva/data/MoreData.htm
Direct download link: http://www.cipotato.org/diva/data/misc/world_adm0.zip

For more on using this shapefile, see our posts on using QGIS.

Layer 2: World Raster

The second data layer is a raster image of the entire world. The original image was very large but we downloaded it and resized to 600 x 300 pixels. Additionally, we had to create a world file to ensure it would spatially align correctly with our countries shapefile (see this post for more instructions).

World Raster

Source: http://commons.wikimedia.org/wiki/World_map
Direct link to full-size image (8 MB): http://upload.wikimedia.org/wikipedia/commons/c/cf/WorldMap-A_non-Frame.png
Resized Image: http://www.spatialhorizons.com/downloads/world_raster.tif
World File: http://www.spatialhorizons.com/downloads/world_raster.tfw

Mapfile Creation

The World Map dataset has been used for several of our projects involving MapServer. Since MapServer requires a configuration file called a mapfile, one was generated using QGIS in this post. Some minor modifications were made later on so the final version can be downloaded here.

In the mapfile, the file paths to the data layers should be changed though to reflect your directory structure.

 LAYER
    NAME 'world_raster'
    TYPE RASTER
    DATA 'C:\\Data\\World\\world_raster.tif'
  ...

LAYER
    NAME 'world_adm0'
    TYPE POLYGON
    DATA 'C:\\Data\\World\\world_adm0.shp'
  ...