Global Positioning Systems (GPS) use satellites for navigation. Receivers with GPS technology can decipher their location (latitude, longitude, and altitude) through radio signals. There are over two dozen satellites in orbit, broadcasting precise timing signals for receivers.

      In my mapping I used a GPS receiver to gather latitudes, longitudes, and altitudes in Whispering Woods as references for the extent of the invasive species. I was planning to use this data to make the Infestation Maps, but I do not have the required software to manipulate this digital information. Some countries are using this technology to establish invasive species databases. When taking my data points, I only ever had a maximum accuracy of 6m. This lack of accuracy was especially noticeable in the elevations. For example, when walking downhill, the altitude reading would stay the same, or even go up in some cases. Some GPS receivers are accurate to very slight movements; mine was not, so it was not good for the detail of mapping I required. Thus, I relied on my drawn maps to show the extent of the brome, thistle, and creeping bellflower.