What is GIS? | How does GIS work? | What is GIS data? | How can I use GIS?

What is GIS?

As stated by the USGS, a Geographic Information System (GIS) "is a computer system capable of capturing, storing, analyzing, and displaying geographically referenced information; that is, data identified according to location." GIS was invented by Canada Land Inventory geographer Roger Tomlinson in the 1960s.

How does GIS work?

GIS is the combination of three components: geographically enabled data, analysis tools (software), and a visual representation (map). In other words, GIS software can read geospatial data and display it as a map, and also perform geographic analysis.

GIS technology is how the Uber app knows which driver is closest to you, why you can follow their progress to your location, and how the driver knows how to get you to your destination. Some other examples of GIS analysis include but are not limited to: analyzing elevation data to find the easiest route through a mountain range; calculating how many shawarma restaurants there are in Centretown based on neighbourhood boundaries and restaurant locations; determining ideal moose habitats based on vegetation, wetland locations, and proximity to civilization.

What is GIS data?

GIS data - also called geographically enabled data or geospatial data - comes in a wide variety of formats with one thing in common: a geographic component. That geographic component could be a country name, street address, latitude and longitude coordinates, city name, or anything else that designates a specific spot or area on the surface of the earth. In fact, a spreadsheet of data with a geographic component can almost always be mapped using GIS software.

Datasets in GIS formats can be classified into two broad categories: raster data and vector data.

Raster data

Raster data is a type of digital image represented by reducible and enlargeable grids or pixels, wherein each pixel has a value. Examples of raster data include air photos (each pixel's value is a colour) and digital elevation models (each pixel's value is a number representing height above sea level). Common file formats include JPEG, GeoTIFF, and MrSID.

Vector data

Vector data consists of points, lines, or polygons. Examples of vector data include hospital locations (points), roads (lines), and lakes (polygons, which have area). Common vector file formats include shapefiles, Google Earth KML, and AutoCAD drawing files.

How can I use GIS?

GIS can be used for such a wide range of applications that the key thing to know is this: if your data has a geographic component (address, country, latitude and longitude coordinates, city, etc.), then you can very likely use GIS software to map it. We are more than happy to speak with you about the project you have in mind if you would like to know what the next steps should be.

GIS: What is GIS? (PDF)

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