Project Summary

Project image thumnail

Parcel Comparison Web Application

Developed a web-based parcel mapping application

Project Problem

In 2001, Great Arc developed an Internet site that allowed Cook County property owners and other public users to view property tax and assessment information, as well as an interactive map, using ArcIMS. Following the delivery of the initial site, Great Arc had made various modifications and enhancements to the original application. By 2006, the Assessor’s Office decided that they would like to add more functionality and enhance the application further.

Project Solution

Because the County wanted to add functionality to the application and change the existing application interface, it was determined that Great Arc would replace the existing application by developing one using C#.Net and ArcXML, rather than ASP and the ActiveX Connector. Additionally, Great Arc would develop the framework of the application using XML. This approach allowed the Assessor’s Office greater flexibility for updating the look and feel, as well as some components of the functionality of the application without having to write additional code. Other parts of the project included installing and configuring ArcIMS and ArcSDE on a new server, and building a data migration tool for moving updated parcels into the application.

Great Arc also developed a web service to generate property images for display in the application based on the parcel identification number. The picture was cut from a video frame which is part of a video collection spanning every street in Cook County. This web service is used by multiple web applications throughout the County. Another web service was created to simply create ArcIMS-generated images showing a select number of parcels highlighted. This web service was built to allow County developers access to simple maps without needing to understand ArcIMS programming.

A final piece of the puzzle is an ArcObjects application that Great Arc developed to move parcels from the County’s DB2 SDE database to the SQL Server SDE database. This application examines data in the DB2 database against a table that tracks what parcels should be updated in the SQL Server database. This allowed the Assessor’s office to automatically keep the Application data in sync with the production databases.



  • Javascript
  • ArcSDE
  • SQL Server
  • ArcIMS
  • ArcObjects
  • MapXtender
  • HTML
  • Web Services
  • C#
  • Visual Basic