GIS Lecture: Geocoding 100 Elm Street 198 101 199

Outline Geocoding Overview – aka Address Matching Linear (Street) Geocoding Problems and Solutions Polygon Geocoding Geocoding in ArcGIS Online Geocoding in ArcMap

Geocoding Overview

Geocoding Address Matching process of creating geometric representations for locations (point features) from descriptions of locations (addresses) Displays tabular data containing addresses as points on a map Finds locations on a map easily

Geocoding Examples Emergency dispatch operators geocode an address to determine who should respond to an emergency call County health director maps personal care and nursing homes and compares them to elderly population by neighborhood Business maps store locations and compares to competitor locations More?

Source data Tabular data street addresses zip codes

Destination data Geographic Data street centerlines zip code polygons

Linear (Street) Geocoding

Address Components Number 123 Oak ST E, Apt. 2, Pittsburgh, PA 15213 Street Name 123 Oak ST E, Apt. 2, Pittsburgh, PA 15213 Street Type 123 Oak ST E, Apt. 2, Pittsburgh, PA 15213 Direction, suffix 123 Oak ST E, Apt. 2, Pittsburgh, PA 15213 Direction, prefix 123 E Oak ST, Apt. 2, Pittsburgh, PA 15213 Unit Number 123 Oak ST E, Apt. 2, Pittsburgh, PA 15213 Zone, city 123 Oak ST E, Apt. 2, Pittsburgh, PA 15213 Zone, zip code 123 Oak ST E, Apt. 2, Pittsburgh, PA 15213 Items for Single Number Street Address: Address Unit City Zip Code 123 Oak ST E Apt. 2 Pittsburgh 15213

Linear Geocoding (Streets) Urban street maps four street address numbers ranging from low to high for each side of a street segment 100 Oak Street 198 101 199 Left_from Left_to Right_from Right_to Street_name Type 100 198 101 199 OAK ST

Geocoding Result Best Candidate Matched From To Street Type Side Parity Direction Street_ 101 199 Oak St R O E 4357 Oak St Pine Av 100 101 198 199 123 2 1 98 99

Problems and Solutions

Possible Problems Variations in Street Names Fifth Avenue, Fifth Ave., 5th AV Saw Mill Run, Route 51

Possible Problems Variations in Street Names Data Entry Errors Fifth Avenue, Fifth Ave., 5th AV Saw Mill Run, Route 51 Data Entry Errors Fidth Avenue Sawmill Run

Possible Problems Variations in Street Names Data Entry Errors Fifth Avenue, Fifth Ave., 5th AV Saw Mill Run, Route 51 Data Entry Errors Fidth Avenue Sawmill Run Place Names White House, Heinz Field, Empire State Building

Possible Problems Variations in Street Names Data Entry Errors Fifth Avenue, Fifth Ave., 5th AV Saw Mill Run, Route 51 Data Entry Errors Fidth Avenue Sawmill Run Place Names White House, Heinz Field, Empire State Building Intersections 5th AV and Craig ST

Possible Problems Variations in Street Names Data Entry Errors Fifth Avenue, Fifth Ave., 5th AV Saw Mill Run, Route 51 Data Entry Errors Fidth Avenue Sawmill Run Place Names White House, Heinz Field, Empire State Building Intersections 5th AV and Craig ST Zones 100 Main ST 15101, 100 Main ST 16202

Possible Problems Variations in Street Names Data Entry Errors Fifth Avenue, Fifth Ave., 5th AV Saw Mill Run, Route 51 Data Entry Errors Fidth Avenue Sawmill Run Place Names White House, Heinz Field, Empire State Building Intersections 5th AV and Craig ST Zones 100 Main ST 15101, 100 Main ST 16202 Post Office Boxes P.O. Box 125

Solutions Clean your data before geocoding Use postal address standards Publication 28 of the U.S. Post Office (2000) provides standard street address formats Use Standard Intersection Connectors & | @

Street Intersections Put street intersections in the address field Forbes AV & Craig ST Grant ST & 5th AV E North Star RD & Duncan AV Do not include street numbers 3999 Forbes Ave & 100 Craig St

Solutions Use Alias Table Alias Address White House 1600 Pennsylvania Avenue Heinz Field 100 Art Rooney Avenue Empire State Building 350 5th Ave

Other Geocoding Layers Polygons parcels, census blocks, tracts, places, counties, etc. Points landmarks such as churches, schools, and other cultural features represented as points

Polygon Geocoding

Polygon Geocoding (Zip Codes) Points created at zip code centroids

Polygon Geocoding (Zip Codes) Spatially join to make choropleth map Points to Polygons

Geocoding in ArcGIS Online

Evolution of Geocoding ArcMap create an Address Locator Address Locator is a file that tells ArcMap how to match your addresses you can still do this! Arc GIS Online starting in 2012 at version 10.1 using ESRI’s online Address Locator

ESRI Address Locator Easier  but Not free  Costs “credits” online fee-for-service model Costs “credits” online ArcGIS trial account to get free credits 200 free credits = 4000 addresses geocoded Used within ArcMap - but must have an internet connection

Geocoding Online In ArcMap TOC, right-click your table > Geocode Addresses Choose Address Locator World Geocoding for Online AddressLocator for ArcMap Log in to ArcGIS Online

Run the Geocode Set Geocoding fields Name your output points layer OK Address City State Zip Name your output points layer OK

Geocoding Results View geocoding results - M, T, or U Interactive Rematch

Voila!

Geocoding in ArcMap

Create Address Locator In ArcCatalog, create a New > Address Locator Choose Address Locator style

Choose destination layer Streets, ZIP Codes

Address Locator Properties

Geocode in ArcMap Add tabular data and streets layer Add your Address Locator Then the same steps as Online Voila!

Summary Geocoding Overview – aka Address Matching Linear (Street) Geocoding Problems and Solutions Polygon Geocoding Geocoding in ArcGIS Online Geocoding in ArcMap