Lecture 5 Geocoding in ArcGIS 5-1 Automate geocoding process Objective of geocoding – to find x, y coordinates for non-graphic objects (such as addresses) in a documented geographic or projected coordinate system. (This process is also called address matching.) In order to convert an address table (.dbf file) into a GIS dataset (a point layer, such as shapefile, or arc file in a coverage/geodatabase), you need a reference data set for locating those addresses. What we can find this reference data set? 2018/11/24 Jun Liang, Geography @ UNC

5-2 U.S. census bureau and TIGER/LINE The U.S. census bureau maintains a database of streets with address ranges which has been enhanced in many commercial geocoding products. For an overview of TIGER: http://www.census.gov/geo/www/tiger/overview.html You can check the web page for North Carolina’s 2003 TIGER dataset: http://www.census.gov/geo/www/tiger/tiger2003/tgr2003.html To pick up the right dataset, you may also need to check: http://www.census.gov/geo/tigerline/app_a02.pdf Can we use TIGER dataset in ArcGIS, or ArcView directly? 2018/11/24 Jun Liang, Geography @ UNC

5-2 U.S. census bureau and TIGER/LINE (Cont.) You can not use TIGER dataset in ArcGIS/Arcview directly. In order to use them, you will need to convert them into coverage, or shapefile. Tool required for this conversion: ArcToolbox -> Conversion Tools -> Import to Coverage -> Tiger to Coverage Wizard 2018/11/24 Jun Liang, Geography @ UNC

5-2 U.S. census bureau and TIGER/LINE (Cont.) Several important issues about conversion: Prefix - You will see that the prefix is always "TGR(state FIPS)(county FIPS).RT“ Select it and press OK. Should you choose to create one polygon coverage that contains the line and area attributes, or three coverage: a point, a line, and a polygon coverage? For the first choice, the result will have no linear topology, or point features. So you need to select the second option, if what you want is more than just displaying polygons. 2018/11/24 Jun Liang, Geography @ UNC

5-3 Set up address locator To configure the geocoding reference dataset in ArcGIS, we need to set up the reference dataset using an Address Locator file. Procedures to do this: In ArcCatalog open the Address Locator folder and create a new Address Locator. In the first dialog box, choose the style of the geocoding service. In the next dialog box, set the Reference Data property to point to your copy of the streets file. Configure all the options for your Address Locator. Copy this address locator to your working directory. 2018/11/24 Jun Liang, Geography @ UNC

5-4 Geocoding/Address Matching in ArcMap Once you set up your Address Locator, you are able to geocode any address tables, which locate within the address locator. (You can not use a NC reference dataset to geocode a NY address table.) General steps: Select the geocoding function from tool menu. Choose the right address locator Configure parameters for the lcoator Run the geocoding process Manually fix the unmatched addresses. You will get a new point layer. 2018/11/24 Jun Liang, Geography @ UNC