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Where are we? An introduction to GIS
Perhaps you have used MapQuest or Google Maps to find a location or to get directions. Or maybe you've used Google Earth to see a 3D representation of the Grand Canyon. But did you know that these applications are examples of a much broader category of software known as GIS -- Geographic Information Systems?
A GIS is a system for working with computerized maps, but it's more than just a digital atlas. In a GIS there's a database associated with each map and information can be tied to each map element. This makes it possible to find information using the map, or conversely to locate map elements that meet some special criteria.
For example, archeologists use GIS to create detailed maps of archeological sites. A grid is created and all the data associated with each cell is entered into the database. This includes what was found in that call, but it can also include information about the terrain, or anything else of interest. Once the data is in the computer the GIS can be used to answer questions like, "identify each cell where pottery was found that is within 100 meters of a grain storage unit." Or, "select the cells where more than 5 arrowheads or spear points were found." In this case, seeing concentrations of artifacts associated with warfare can help a scientist visualize the flow and ebb of an ancient battle.
This is just one example and GIS is used in a number of different scientific disciplines. But it is also heavily used for business and management tasks. An example from business is something called districting. A sales manager can use a GIS to balance sales territories based on the distribution of the company's customers. So if one territory contains 1000 customers, and an adjacent territory contains 500 customers, the districting tool of the GIS can create new boundaries with 750 customers in each territory. And that's just the start, the manager can also analysis driving distances to ensure that the new territories can be effectively covered by car.
A third example of GIS in action is one that you may have used in your own car (or in a rental). In-car navigation systems use a GIS tool known as GPS. In this use a Global Positioning System (GPS) unit receives signals from a group of satellites, and using the differences in the time it takes for the signals to reach it, is able calculate the location (longitude, latitude, and elevation). The locational information is then combined with route finding software to allow the unit to tell you where you are and how to get to where you want to go.
There's so much more that you can learn about GIS and GPS, and many sources and resources to help you do it. And that's the point of this Bit Literate Guide. We've identified the best resources have listed some of them below. GIS is a big topic, so we can't cover everything, but these are good places to start.
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