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A Publication Featuring The Information
Services Technology of Maine State Government
| Volume VII, Issue 4 | April 2004 |
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By Cindy Owings
For some time employees of the Maine Department of Transportation’s (DOT) Information Systems Division had been looking for a way to provide internet mapping functionality to our internal users and the public. In 2002, ESRI[1] released their ArcIMS mapping services software, a technology deemed advanced enough for MaineDOT to move ahead in this direction.
The Information Systems Division was chosen to develop an application for the Maine DOT Photogrammetry and Control Unit (PCU) that would be available to internal project development employees and the general public, specifically targeting surveyors throughout the state who often call MaineDOT for control point information in the field.
Maine DOT took an unusual approach and decided that this project would be developed using a "technology transfer" contract with ESRI. Early in the project, Andrew Hite, a technical support person from ESRI, was introduced to the MaineDOT programmers assigned to the project, and together they formed the team of developers to produce the Survey Control application. Because of its compatibility with ArcIMS and Oracle, and the desire to train programmers with this skill, Java was the language chosen for the customization of this ArcIMS Image Server application.
In this application, like most applications, data is at the heart of the matter. For this application ArcSDE data is used from both MeGIS and MaineDOT SDE servers to display information on the web page. ArcSDE is a geographic application server that uses the leading commercial database management systems (DBMS) to store vector, raster, and survey data. By using SDE, MaineDOT has the ability to use data that is not maintained at MaineDOT; this data is important for presenting the desired map presentation for the interface of the application.
This is also the first time MaineDOT has implemented a solution using Oracle Spatial. Why Oracle Spatial? Maine DOT prefers to not be locked into using a vendor specific product for all applications that need to use spatial data. There are potentially many applications that can use a spatial type query without the users requiring a map interface. For instance finding lists of addresses for labeling within an area is possible without using an ESRI product if your data is stored in Oracle Spatial.
An Oracle user can query the database using spatial data operators such as: “Adjacent to”, “Within a distance of”, “Contained by”, “Intersecting with” or “Buffer around a feature”. Since these spatial operators are just extensions to SQL they can be used in any application that accesses Oracle Spatial. This provides flexibility to MaineDOT to develop and purchase applications that support spatial querying without the necessity to use sophisticated GIS software, and then in turn, the expense of licensing for that software is also reduced.
The original process used ArcView 3.x, a Microsoft Access database for the presentation layer and Oracle for the data storage. The new Application utilizes ArcMap 8.1, ArcIMS 4.1, ArcSDE, Microsoft Access, Oracle Spatial, and Oracle Reports. Oracle Reports was chosen for its ability to produce multiple types of output from one report specification. Minor changes in the Microsoft Access presentation layer were required to point the forms and reports to the new RDMS. The availability of the control points data and reports on the web will save the PCU hours of time producing and mailing paper reports.
When asked about the benefits of this website, Tim LeSiege, an engineer with PCU, replied, "The creation of the control web page has benefited the Department and the surveying profession immensely" … " With the advent of the page, the surveyors and engineers can now visit the site 24 hours a day, 7 days a week and not have to try to call during Department business hours in hopes of reaching one of the few employees who have traditionally provided this service. Most of the surveyors have already learned about the web page and are actively using it!" According to LeSiege, the unit will see at least a $12,500 annual savings by freeing up the time of the employees who previously served the public requests.
The following are part of the developer's toolbox for this application: Java, JDeveloper, XML, Technology Transfer Contract with ESRI, Oracle Reports Developer and Oracle 9iAS Enterprise Manager.
The result of all these different technologies working together can be seen at Maine DOT's first internet mapping web page: http://mainedot.maine.gov/survey.
The Information Systems Division plans to leverage the investment in learning to apply these various technologies by creating solutions for several other business needs using lessons learned from this project. Other potential internet mapping solutions include a utilities application for right-of-way work, an application to provide project locations data to the public, an internal data warehouse solution, a road-side spray application and the route-log-mile system for viewing road data.
Questions? Contact the author, who is a Programmer Analyst, by e-mailing cindy.owings@maine.gov. Cindy has worked for MaineDOT since 2000 and has been working for the Information Systems Division since May, 2001.
