California Home
CDPH Home
EHIB Home
What's New
About EHIB
Mission
Sections
People
Jobs
Contact
Newsletters
Topics
Projects
Papers/Fact Sheets
FAQs
Related Links
Partners
Tools
Search
CEHTP Centralized Geocoding Demonstration
This web page is an example of a client that utilizes the California Environmental Health Tracking Program's (CEHTP) centralized geocoding service.
Problem
Historically, health event data have imperfect geocoding success rates.
e.g. Birth Master File = 95%, Medi-Cal = 85%.
We want 100%!
High quality address data, or, more preferably, pre-geocoded data, prepares CEHTP to perform ongoing/systematic/automated GIS visualization and spatial linkage with environmental hazard datasets. Geocoding should be done as early as possible in the data collection process.
Programs that receive reported data and compile them for official release might not have resources or mandate for geocoding or ensuring high quality address data. Geocoding can be expensive.
Programs may desire GIS visualization services for their data product. This is not possible unless the geography of the data is coded and of high quality.
Click
here
for a workshop presentation on centralized geocoding requirements and implementation.
Solution
Assist programs in standardizing, verifying, and/or geocoding their address data to latitude/longitude coordinates and any other political boundaries (e.g. Census Block Group, Public Land Survey, etc.).
Provide a centralized geocoding service that is available over the network, secure, interoperable, easy to integrate with existing reporting mechanisms, easy to implement (modular, platform independent, and extensible), and has high geocode success rates.
EHIB's geocoding expertise is exposed as web services. XML-based Simple Object Access Protocol (SOAP) is a WWW standard for application-to-application communication.
Benefits
No/low cost of ownership for programs that utilize service. CEHTP has incentive to provide this service to partnering programs within CDPH. CEHTP has in-house expertise to ensure that programs are utilizing the geocoding service successfully.
CDPH programs have easy access to EHIB's GIS knowledge base and value-added tools over the local network or externally.
Web services can be invoked from any platform that can send/receive XML documents. CEHTP will provide participating programs pre-packaged .NET (C#), Java clients, or other clients (C++,VB, etc.), if feasible. CEHTP will also provide participating programs more robust example client applications that interact with an RDBMS.
Geocoding service is available for applications on CDPH Intranet and Internet. Secure Sockets Layer (SSL) can be used for encrypted transmissions.
Advocacy/New Data
CEHTP is constantly looking for new ways to improve geocoding match rates and positional accuracy. For example, we are looking at ways to utilize master address files and real property polygons as well as to convert PO Boxes into residential addresses through contact with local postmasters.
When new data/tools become available, CEHTP can incorporate them into the geocoding engine with little disruption to clients.
Client Examples
Manually invoked batch database updater -- Operator decides when to start process that updates multiple addresses in address table with geocode information. We currently offer our Tracking partners .NET- and Java-based batch geocoding clients. The .NET client, called Tables Address Geocoder (TAG), has a user-friendly interface, runs on Windows platform only, and can geocode an address table in the following formats: flat text, Excel, Access, SQL Server. The Java client is DOS-based, runs on any OS platform, and can only geocode SQL Server tables.
Record-level database trigger -- When a new record is added to address table, address is automatically geocoded and geocode results are stored in table.
Record-level web form tie-in -- Similar to this demonstration, clients can customize their reporting applications to incorporate geocoding methods offered through this service. Quality and geocoding success can be assured at the time of data entry.
Request Service
Send an email request to
Craig Wolff
. In your message please indicate the specific type of data you will be geocoding, whether you believe this data has a relationship to environmental hazards/exposures, and whether you would like to geocode your data as it's reported (real-time electronically) or in batch (long after it's reported).
Enter an address in California:
Address
City
Zip
Street Address
|
City
|
Zip
1113 Hunterston Plac|Cupratino| 1026 Taylor|Alameda|94502 10857 Wilkns Avneue|Los Angeles|90023
Enter one address
Show formatted output
Yes
No
1. Return record ID of reference database?
2. Return standardized address/city/zip?
3. Return ID's of underlying regions?
4. Use zip code as look up index?
5. Use city soundex as look up index?
6. For multiple street databases, return first matched coordinate only?
7. For multiple street databases, return distance from centroid of coordinates (average error)?
8. Specify side offset
and side offset units (street reference databases only)
Decimal Degrees
Feet
Kilometers
Meters
Miles
Reference data units
Yards
9. Specify reference database (locator) to use
TeleAtlas Address Points 2008
Google Geocoder
TeleAtlas Streets 2008
TIGER Streets 2008
GDT Streets 2005
Yahoo Geocoder
TeleAtlas Zip+4 Centroids 2008
10. Specify regions to overlay and extract
Census 2000 Block Group
Medical Service Study Area 2000
© 2007 State of California.
Conditions of Use
Privacy Policy
