GIS & Mapping

Geocoding is the process of transforming a table of street addresses into longitude and latitude coordinates. While finding a coordinate for a single point may be simpler to geocode manually, if you need tens or hundreds of addresses transformed into coordinates, you will want to use a batch geocoder.

For more information about what geocoding is, why we do it, and how it works, please read the guide "Geocoding in ArcGIS" from the makers of ArcGIS, ESRI.

We will help you with your geocoding needs! If you have a list of addresses that you want geocoded and are a part of the Penn community (i.e. you have a @upenn.edu email address) please do not hesitate to write to LibraryGIS@pobox.upenn.edu.

Geocoding takes a table of addresses and converts them to actual locations with latitude and longitude. With the geocoding capability of ArcGIS, a powerful geographic information system (GIS), you can turn a list of addresses into spatial data for mapping or combining with other data. The output is in the form of points in the shapefile format.

ArcGIS needs two kinds of files in order to geocode:

1. A table of addresses. This can be in Excel, CSV, DBF, or TXT files. They can be full street addresses or more general areas, such as ZIP codes. If you are using an Excel file (XLS or XLSX), there are some tips and tricks you can follow to avoid problems.
   
   The address data must be in a specific format depending on the kind of address. For street addresses, the table must have separate columns for number and street, city, state, and ZIP.
   
   
2. An address locator. This is the information that ArcGIS uses to assign a location to an address. For geocoding full street addresses, the address locator will contain street segments with ranges of addresses on the right and left side of the street. For geocoding ZIP codes, the address locator will simply be a map of ZIP code areas.