In my previous blog, I discussed mailing cities and zip codes and how they represent geographic location. Now let’s take a look at how geographic location can be determined from an address.
Geocoding (sometimes called geolocating) is the act of assigning geographic coordinates (latitude and longitude) to a description of a location. You can geocode a postal address or a group of postal addresses (like a zip+4) using street-level geocoding. This geocoding process depends upon a road base, or a roads data set in which each road segment is attributed with address ranges (meaning address ranges are assigned to each segment). The address location is estimated based on where the number of the address falls within the range of addresses that the road segment represents. For example, if a road segment runs west to east and covers a range of addresses of 801 to 898, then an address of 825 would be further west than an address of 880.
I’d like to thank Dave Martin, my fellow Senior GIS Analyst, for the above geocoding example.