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This demonstration illustrates how the address ranges encoded in TIGER/Line Shapefiles can be used to pinpoint (more or less!) the geographic locations of street addresses in the U.S. The demo uses an early version (2.0.8) of a free software tool for data viewing called ArcExplorer, which is made by Environmental Systems Research Institute (ESRI). I use this early version (which ESRI no longer supports) because the latest version of ArcExplorer doesn't support address geocoding in the revealing manner that this version does. You can also open TIGER/Line Shapefiles and geocode addresses with dlgv32 Pro (Global Mapper), and in other proprietary GIS software packages, but these experiences are not as instructive, I think, as what you'll see in this demo. Registered students can retrieve a copy of the ArcExplorer 2 software from the Chapter 4 folder in ANGEL.
- Downloading TIGER/Line Shapefiles: You're going to use the 2009 TIGER/Line Shapefiles.
- Link directly to the 2009 TIGER/Line Shapefiles at: http://www.census.gov/geo/www/tiger/
- Navigate under the first main heading to the "2009 TIGER/Line Shapefiles Main Page".
- Select "Download the 2009 Shapefiles now".
- Select and submit a state (upper right portion of your screen).
- Select and submit a county (left side of screen).
- Click the check boxes for the following layer: "All Lines" and download selected file.
- Save the file to your computer.
- The data are compressed in a .zip archive. Extract the data to a new named folder in a known location. (Within the file hierarchy that is extracted there is apt to be a second .zip file that needs to be uncompressed.)
- Geocoding in ArcExplorer 2: Here are the steps to geocode your address using the downloaded 2009 TIGER/Line Shapefiles .
- Choose "Add Theme" from the "Theme" menu. Navigate the Add Theme window to add the downloaded and extracted shapefile data. (Your shapefile will have a name similar to "tl_2009_42027_edges"--the "42027" represents Pennsylvania, state "42", and Centre County, county "027". The five digits in your file name will depend on which state and county you selected.)
- Return to the ArcExplorer window. Turn the lines theme on by checking the box next to it. Double-click the theme shown in the legend in the left-hand frame to access and edit Theme Properties, including line color and boundary fill.
- Make sure that the lines theme is selected in the menu. Then choose "Address Match Properties..." from the "Theme" menu. (Click to see screen capture.)
- In the "Address Match Properties" window, select the address range attributes in the TIGER/Line files that correspond with ArcExplorer's expectations. For example, "Street Name" in TIGER/Line is "FULLNAME" (feature name). "Left From Address" is "LFROMADD" in TIGER/Line. And so on. Sound familiar? (Click to see screen capture.) The new 2009 TIGER/Line Shapefile's field for "FULLNAME" contains a concatenated street address--you DON'T need to include street prefix, type, or suffix.
- After you've configured the Address Match Properties, you'll find that "Address Matcher" becomes available under the "Themes" menu. Choose it. (Click to see screen capture.)
- Enter your street address and ZIP code in the "Address Matching" window. Click "Match." Zoom in. My result appears in this screen capture. Use the "Identify" tool to reveal the attributes of your street segment if your address, like mine, is geocoded incorrectly.
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