Introduction to Geographic Information Systems Spring 2013 (INF 385T-28437) Dr. David Arctur...
description
Transcript of Introduction to Geographic Information Systems Spring 2013 (INF 385T-28437) Dr. David Arctur...
Introduction to Geographic Information Systems Spring 2013 (INF 385T-28437)
Dr. David ArcturLecturer, Research Fellow
University of Texas at Austin
Lectures 8 & 9Feb 28, 2013
8 - Spatial Analysis9 - Geocoding
Geocoding Outline (Tutorial Ch.7) Geocoding overview Linear (street) geocoding Problems and solutions Street map sources Polygon geocoding Geocoding in ArcGIS Useful Web sites
2INF385T(28437) – Spring 2013 – Lecture 9
GEOCODING OVERVIEWLecture 9
3INF385T(28437) – Spring 2013 – Lecture 9
Geocoding Process of creating geometric
representations for locations (e.g., points) from descriptions of locations (e.g., street addresses)
Uses a computer program that employs code tables to standardize address components called a geocoding engine
Two ways to geocode Batch geocoding—attempts to match all
addresses Interactive rematching—sophisticated user
interface to match addresses4INF385T(28437) – Spring 2013 – Lecture 9
5
Geocoding examples City’s economic development department
maps technology businesses by street addresses to see technology-rich areas in a city
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
Emergency dispatch operators geocode an address to determine who should respond to an emergency call
Others?INF385T(28437) – Spring 2013 – Lecture 9
Geocoding files Tabular data (text or dbase)
Street addresses ZIP codes Latitude and longitude
6INF385T(28437) – Spring 2013 – Lecture 9
Geocoding files Geographic data
Street centerlines ZIP code polygons
7INF385T(28437) – Spring 2013 – Lecture 9
Other geocoding files Lines
Railroads, rivers Polylines
Parcels, census blocks, tracts, MCD/CCDs, places, counties, etc.
Points Landmarks such as churches, schools, and
other cultural features represented as TIGER as points
8INF385T(28437) – Spring 2013 – Lecture 9
LINEAR (STREET) GEOCODING
Lecture 9
9INF385T(28437) – Spring 2013 – Lecture 9
Linear geocoding (streets) Urban street maps
Four street address numbers ranging from low to high for each side of a street segment
100 198
101 199
Oak Street
10INF385T(28437) – Spring 2013 – Lecture 9
Geocoding stepsOriginal address: 125 East Oak Street 15213
Address parsed: |125|East|Oak|Street| 15213
Abbreviations standardized: |125|E|Oak|St|15213
Elements assigned to match keys:[HN]:125 [SN]:Oak[ST]:St [SD]:E [ZP]:15213
Index values calculated: [HN]:125 [SN]:Oak(Soundex # ) [ST]:St [SD]:E [ZP]:15213 (Index #)
11INF385T(28437) – Spring 2013 – Lecture 9
Geocoding steps
From To Street Type Side Parity Direction Street_2 98 Oak St R E W 43441 99 Oak St L O W 4345100 198 Oak St R E E 4346101 199 Oak St L O E 4357
Candidates identified: 125 East Oak Street15213
Candidates scored and filtered:
From To Street Type Side Parity Direction Street_100 198 Oak St R E E 4346101 199 Oak St L O E 4357
12INF385T(28437) – Spring 2013 – Lecture 9
Geocoding steps
From To Street Type Side Parity Direction Street_101 199 Oak St L O E 4357
Best candidate matched
Oak StPi
ne A
v100101
198199
123
21
9899
13INF385T(28437) – Spring 2013 – Lecture 9
Number 123 Oak St E, Apt. 2, Pittsburgh, PA 15213Street name 123 Oak St E, Apt. 2, Pittsburgh, PA 15213Street type 123 Oak St E, Apt. 2, Pittsburgh, PA 15213Direction, suffix 123 Oak St E, Apt. 2, Pittsburgh, PA 15213Direction, prefix 123 E Oak St, Apt. 2, Pittsburgh, PA
15213Unit number 123 Oak St E, Apt. 2, Pittsburgh, PA 15213Zone, city 123 Oak St E, Apt. 2, Pittsburgh, PA 15213Zone, 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
Address components
14INF385T(28437) – Spring 2013 – Lecture 9
PROBLEMS AND SOLUTIONSLecture 9
15INF385T(28437) – Spring 2013 – Lecture 9
Possible problems Variations in street names
Fifth Avenue, Fifth Ave., 5th AV Saw Mill Run Blvd, Route 51
Data entry errors Fidth Avenue Sawmill Run
Place Names White House, Heinz Field, Empire State Building
Intersections Fifth Avenue and Craig Street
16INF385T(28437) – Spring 2013 – Lecture 9
Possible problems Zones
100 Main ST 15101, 100 Main ST 16202 P.O. boxes
P.O. Box 125 Missing street (TIGER) information
17INF385T(28437) – Spring 2013 – Lecture 9
18
Solutions Clean data before geocoding Use postal address standards
Publication 28 of the U.S. Post Office (2000) Ultimate source on mailing address formats and
codes Provides standard street address formats Standards include house number, prefix
directional, street name, street suffix, common unit designator abbreviation for apartment, city, state abbreviation, five-digit ZIP code, ZIP+4 extension
Use Standard Intersection Connectors & | @INF385T(28437) – Spring 2013 – Lecture 9
19
Solutions Use alias tables
Points of Interest (POI) databases; gazetteers
Assign house numbers in rural areas Purchase or build high quality maps
(field verification)INF385T(28437) – Spring 2013 – Lecture 9
Alias AddressWhite House 1600 Pennsylvania AvenueHeinz Field 100 Art Rooney Avenue Empire State Building 350 5th Ave
STREET MAP SOURCESLecture 9
20INF385T(28437) – Spring 2013 – Lecture 9
TIGER/Line files 2000 Census street centerlines
21INF385T(28437) – Spring 2013 – Lecture 9
Caution: source has changed
TIGER/Line files
23INF385T(28437) – Spring 2013 – Lecture 9
Caution: source has changed
25
Commercial sources for maps GDT / ETAK / TeleAtlas TomTom.com
All the big pioneers of streetmaps are now TomTom
Esri StreetMap Premium for ArcGIS No more free streetmaps
MapBox.com (free & fee)
Others…?INF385T(28437) – Spring 2013 – Lecture 9
26
OpenStreetMap.org (free open-source)
INF385T(28437) – Spring 2013 – Lecture 9
POLYGON GEOCODINGLecture 9
27INF385T(28437) – Spring 2013 – Lecture 9
Polygon geocoding Suppose you wished to make a
choropleth map showing distribution of attendees at an event
Need to geocode data whose identifier is a polygon (e.g. ZIP code, city, or county) Create an aggregate table with a single record
for each unique polygon Count the records for each polygon Join table to corresponding polygon layer Symbolize with a choropleth map or
graduated point symbols 28INF385T(28437) – Spring 2013 – Lecture 9
Polygon geocoding (ZIP codes)
30INF385T(28437) – Spring 2013 – Lecture 9
Polygon geocoding (ZIP codes) Points created at ZIP code centroids
31INF385T(28437) – Spring 2013 – Lecture 9
Polygon geocoding (ZIP codes) Spatially join points to polygons to
make choropleth map
32INF385T(28437) – Spring 2013 – Lecture 9
33
Choropleth map result
INF385T(28437) – Spring 2013 – Lecture 9
GEOCODING IN ARCGISLecture 9
34INF385T(28437) – Spring 2013 – Lecture 9
Create address locator ArcCatalog
35INF385T(28437) – Spring 2013 – Lecture 9
36
Choose address locator style Skeleton of the address locator Based on data tables and reference
layer
INF385T(28437) – Spring 2013 – Lecture 9
Choose reference layer Streets, ZIP codes
INF385T(28437) – Spring 2013 – Lecture 9 37
38
Address locator properties
INF385T(28437) – Spring 2013 – Lecture 9
39
Geocode in ArcMap Add tabular data and streets layer Add address locator Geocode addresses View geocoding results Interactively rematch addresses
INF385T(28437) – Spring 2013 – Lecture 9
40
Address rematching Investigate unmatched addresses
Generally requires expertise with knowledge of local streets
Compare street name in the attributes of streets table and address table
INF385T(28437) – Spring 2013 – Lecture 9
41
Prepare log file Log file includes reasons why
addresses did not geocode Useful for future work on cleaning
addresses or repairing street maps
INF385T(28437) – Spring 2013 – Lecture 9
Incorrect address Possible reason/solution490 Penn Avenue Missing ZIP code111 Hawksworth Spelled incorrectly900 Smallman Street TIGER street missing900 Lib Ave Spelled incorrectly
USEFUL WEBSITESLecture 9
42INF385T(28437) – Spring 2013 – Lecture 9
Useful Web sites http://www.usps.gov/ http://www.geocode.com/ (TomTom fee
service) http://batchgeo.com/ http://www.mapquest.com http://maps.google.com http://www.bing.com/maps/ http://www.zipinfo.com http://zipskinny.com/ Others?
43INF385T(28437) – Spring 2013 – Lecture 9
Geocoding Summary Geocoding overview Linear (street) geocoding Problems and solutions Street map sources Polygon geocoding Geocoding in ArcView Useful Web sites
Complete Assignment 7-1 (7-2 optional)
44INF385T(28437) – Spring 2013 – Lecture 9