Geocoding Lab

About Address Geocoding

ArcView allows you to geographically find addresses, and once found, you are able to display them as themes.  Address Geocoding is the process of assigning addresses to specific locations by using address information located in an existing theme. You can match addresses by entering them into a table and allowing ArcView to read it, or you can enter the addresses interactively.  The following text and images will show you address geocoding by using tables and a reference theme of Omaha which will serve as a base map.  Afterwards, you will have an exercise which will geocode the addresses of Burger King and McDonalds, located in the Omaha area.


photograph courtesy Philip Greenspun


 

Ask yourself a question, "How many of these two restaurants are in Omaha?"  The Yellow Pages was looked at to find the answer.  Burger King has a total of 24 facilities in Omaha, whereas McDonalds has five less with a total of 19.   The following two jpeg images are the addresses of the two facilities along with telephone numbers.  Database Files were created for the tables.

To find the addresses, a base map or reference theme is needed.  This image shows the Omaha area which will be used as the base map for this project.

The addresses are taken and geocoded with the basemap.  ArcView compares the street information of the basemap to the addresses in the table. The addresses are matched and a point is added onto the basemap at their specific location.  When the first address is matched, a new theme is created.  The following two jpeg images show the location of Burger King and McDonalds in Omaha.  Notice the disbursement throughout Omaha.

Burger King

McDonalds


 


As you have already seen, ArcView allows you to combine more than one theme. The following jpeg image shows the street map theme, the McDonalds theme and the Burger King theme combined.  Notice how close some of the restaurants are located to each other.
 
 

Once you have the themes combined, you are able to identify point or even the streets.  Burger King and McDonalds are identified below showing the addresses and telephone numbers.  The restaurant is located above the top right-hand corner of the box.
 


Address geocoding can be used for many different types of projects.  What you have seen is only a few ways that geocoding can be used.

EXERCISE

The object of this exercise is to geocode addresses of McDonalds and Burger King.

I.  Getting Data:

  1. Scroll down to and click on the Download data file link on the GIS Web page.
  2. Choose to save this file to disk (hold right-mouse button down and choose Save Target As)
  3. Save the file as goecode in My Documents as a zip file

 

II.  Unzipping the ZIP file and adding the shapefile to a new empty map:

  1. Right click on the geocode.zip file and choose Extract to: Geocode.
  2. Open ArcMap, open an empty new map and add the street.shp
  3. Save your project as geocoding.mxd

 

Part I (Address Coding)

III.  Building Geocoding Indexes

Before you can start address matching you must first "Build geocoding indexes."  Open the ArcToolbox and open Geocoding Tools > Geocode Addresses. For the Input Table browse first the BurgerK.dbf from your unzipped folder. Next, browse the streets.mxs file from the same folder as the address locator to use to geocode the address table. For the Alias Name choose ADDRESS_LA from the dropdown menu in the box below. The output shapefile path should be created automatically. If not browse to your folder and name the file BurgerK_GeocodeAddresses.shp. Click OK and Close when the process is completed. Select Red for the Burger King points (double click on the dot). Repeat this process to create the McDonalds_GeocodeAddresses.shp. Choose Blue for its color.

 

 

IV.  Address Matching

Not all addresses could have been matched. To correct them and rematch them right-click on the McDonalds_GeocodeAddress layer and choose Data, then click Review/Rematch Addresses. Check Unmatched Addresses and click Match Interactively. Here you see the addresses which could not be matches. Highlight 11330 EST Dodge Rd and click Modify. Type in W in PreDir and retype Dodge Rd to just Dodge. Press the Tab key after your entries so that your changes go to the box below. Click Match and you now have a 100% match in the Score column. Highlight 12411 EST Center St and type in W for PreDir and Center in the Name field. Click Close.
Now rematch the two unmatched addresses in the Burger King table in the same way. For 14404 West Center St, change the HouseNum to 14405 and for 7205 Ontario St set the number to 7255.

 

Part II (Spatial Analysis)

 Adding a new table

1.     Open ArcCatalog and move to your folder. Right-click in the right window and choose New > Personal Geodatabase. Name it home.

2.     Double click on it and create a new table also named home by right-clicking and choosing New > Table.

3.     Now go the Windows Explorer and open the home.mdb with Access by double clicking on it. When the security warning comes up click Open.

4.     Open your table home by double clicking on it. Go to the Design View by choosing View > Design View from the main menu bar.

5. Create three colums named OID, My Address, and Name (under Field Name) and assign the OID the Data Type Number and the others Text.

6. Go to the Datasheet View with View > Datasheet View and say Yes to the saving question. Now type your home address in My Address and My home under Name. The OID number should be 1.

7.  Add the table to your project and open it to test whether everything is there.

8. Now geocode your address following the steps you did earlier. You might have to rematch the address. (To get a match of your home address you might want to have a look at the street layer (using the i-tool) to find out how your street is named there)

Select by theme analysis

1. Go to View > Data Frame Properties. Go to the General tab and set the Map and Display units to Meters. Click Apply and OK.

2. Click Select by Location in Selection menu.

2. Select Select features from in I want to.

3. Select BurgerK_GeocodeAdresses in the following layers.

4. Select are within a distance of in that.

5. Select home_GeocodeAddresses in the features of that layer.

6. Type 1500 Meters or more and click Apply to select near Burger Kings.

7. Now do the same steps again to display the nearest McDonald's restaurants in your area. To clear the selection click Selection > Clear Selected Features.

8. Create a shapefile of your selected restaurants (right-click on the layer > Data > Export Data > selected Features).

9. Add your shapefiles and make Burger King, McDonald's that you just converted to shape files, home, and street map visible.

10. Use Zoom in tool until you can put selected features in one screen.

11. Go to Layer Properties of each layer and create Labels via the Labels tab. Convert the labels to Annotation Layers (right click on the layer and choose Convert Labels to Annotation) to make them easier for editing.

15.     You can label for your home, burger king, mcdonalds, (and streets - takes a lot of memory).  It’s your choice.

 


Once everything is set to the way you like it, open a layout, change the name, insert a scale and make it presentable.  You should have a layout that looks similar to this.

 

Export the map as geocode.pdf to your folder on the server.

Revised By: Sung-Jun Kim 10-17-2001, updated by Eva Grund, May 2005.