Data Hacking

Chapter 8 — GPS Data
Different types of GPS receivers enable you to store varying numbers of routes, with each route
made up of a different number of waypoints (see Figure 8-11).
Once a route has been tracked by the GPS, it can be reversed so that you can backtrack and
return to where you began.
FIGURE 8-11: Routes
stored in a GPS
Working with the Data
As you can see, a considerable amount of data is stored in a GPS, which means that you need
to be able to access it and work with it. Two principal tasks come into play here:
Working with the data you have already collected with the GPS
Creating new data for upload
Before you can work with existing data, you have to get it off the GPS. Most tools that enable
you to download data from a GPS also enable you to edit the data and work with it at a fundamental
level, editing every aspect of the data. Some purists think that editing any data gathered
by your GPS is not appropriate and prefer to keep it unedited, but others believe that because it
is their data, they can do what they wish with it. There is merit in that opinion — perhaps you
made a mistake when creating a waypoint, took a wrong turn in your journey when you were
recording a route, or missed a few points along the way that you want to add after the fact.
Another good reason to download data from your GPS is that it frees up memory on the device,
enabling you to collect more data.
Everything about the data is editable. Just because you created a route or waypoint while on the
move doesn’t mean that you can’t edit that data later.
At this point, you might be wondering why you have to download the data. Can’t you just edit
the data while it is still on the GPS? You can, but the problem is that you have to input numbers
and data using an input system that is generally prone to error. Furthermore, remember
that when you enter and edit data on a PC, you will normally have the capability to undo any
changes you make, a handy feature not present in the GPS interface.
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