To follow through this section of the chapter, you are going to need access to the GDAL command-line tools. GDAL is probably already installed on your computer, as QGIS makes use of it. If you don't already have GDAL installed, go to www.gdal.org and click on the Downloads link to download and install a copy onto your machine.

One of the challenges of writing a mapping application is to obtain a high-quality basemap on top of which your geospatial data will be displayed. In our case, we want our basemap to show an aerial photograph of the forest. We're going to use the Whakarewarewa Forest in Rotorua, New Zealand, for our ForestTrails application. Fortunately, suitable aerial photographs are available from the Land Information New Zealand website.

Go to the following web page, which provides high-resolution aerial photos for the Bay of Plenty, New Zealand:

https://data.linz.govt.nz/layer/1760-bay-of-plenty-025m-rural-aerial-photos-2011-2012/

We want to download a basemap...