Putting maps and geographic data on the internet

Feature
Spatial Relations: Putting Geodata and Documents on the Same Map
A profile of San Diego Gas & Electric's new web-based mapping and land records management system

By David F. Carr
Senior Editor, Internet World

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If you've ever looked up land records, you know it's at least an annoying, multi-step process: Get the assessor's office to pull the card for your street address, which has a map number on it, check that number against an index that lists the documents associated with the map, then pull the documents one by one from the bound volumes in the vault of the clerk's office.

Ouch.

San Diego Gas & Electric, which tracks more than 1.5 million land records for the areas the utility covers, found that it had replicated a significant number of those steps internally. It had computerized document management and geographical information systems, but they didn't talk to each other. It took the Web and some creativity to bring it all together. In April, after about six months of development and testing, SDG&E launched a streamlined, Web-based solution.
"We've gotten it down to at least a one-step process, where before it was three--three for sure, maybe more," says Bruce Cook, land records administrator for the utility, which is a unit of Sempra Energy.
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Planners and engineers can now look up documents on their own in a matter of minutes, rather than requesting them through the land records department--a process that sometimes used to take days or even weeks. The Web application currently has more than 100 users, and the user base has the potential to grow significantly if access is extended to external customers or to SDG&E workers in the field.
Previously, SDG&E had built its mapping and document management infrastructure to track the properties it owns, the locations of gas and electric lines, right-of-way deeds, and so on. The Web development effort began after Cook's department began exploring the possibility of recovering some of that investment by selling the information to surveyors and other professionals who needed access to the same information. But these potential customers thought the existing system was too hard to work with. They wanted to be able to see at a glance the relationships between the assessor's maps, other types of maps (for things like topography and utility lines), and related documents.
When Robert Hartman, a principal consultant at San Diego Data Processing Corp., became involved in the project, SDG&E officials already had some notion of combining the mapping and document management systems over the Web. "Specifically how they would be integrated, and what form it would take, was a little less clear," he says. Figuring that out became his job.
San Diego Data Processing Corp. (SDDPC) is an oddball among computer consulting firms: It's a non-profit, wholly owned by the city of San Diego, that also offers its services to other firms in the region. Working with geographical information systems (GIS) software is one of its specialties.
These products typically use specialized databases designed to store geographical shapes rather than alphanumeric data. SDG&E's primary GIS vendor is Environmental Systems Research Institute Inc. (ESRI).
SDG&E also scans in documents such as county real estate records, paper maps, and sketches and stores them in a document management system from Altris Software Inc.
SDG&E wanted a common way to navigate through information in both systems.
"What we have now allows you to go to a location on a map and get sort of a MapQuest-like experience. The system then determines, via links in a database, what documents are related to that area, and will return the documents to the user in a Java-based viewer," Hartman says.
Java and COM solution

To generate Web-navigable maps, the new application employs an ESRI Web extension that works with Microsoft Internet Information Server. A SQL Server database implemented specifically for this project uses stored procedures and a COM [Component Object Model] component written by SDDPC to retrieve a list of documents based on a given set of geographical coordinates. The Web user interface is enhanced with JavaScript, and a virtual database implemented as JavaScript arrays allows a browser client to track such information as map numbers between screens, rather than requesting the same information repeatedly from the database.
Once the user clicks on a link to a specific document, it's downloaded using NetVue, an applet-based document viewer from Accusoft Corp. To improve performance, the applet is configured to initially download a low-resolution version of documents such as maps; it will only retrieve a high-resolution version if the user requests a magnified view.
Hartman says the NetVue applet wasn't exactly what he was looking for, but that Accusoft made some modifications.
Cook says the viewer, and particularly its support for printing, is one part of the system that could still be improved. "It would be nice to be able to select a portion of a map to print, rather than the whole map," he says. The viewer will let him magnify an area on screen, but will only print the entire map. To print a section, he has to switch to the client-server document management system.
The project manager for Sempra, Tim Hurley, says that although SDG&E had been making sophisticated use of its GIS system for years, the knowledge about its potential was limited to an "enclave within the organization." By breaking down the walls, he hopes to liberate such knowledge.
"We're trying to do it in such a way that people get excited about the technology," Hurley says. "I'd like to see us do something like this with electricity distribution or gas or marketing. When you put something on the Web, it forces you to dumb down the technology to a certain level--at least at the user interface level--and that's a good thing.
This article originally appeared in Internet World, a publication of Penton Media, Inc. It is reprinted here with the author's gracious permission.