Fig 2 Components and Information Flow
System Development
The crime control system was developed by integrating the Minnesota MapServer, Internet server and crime database into a web based client/server environment (Fig. 2).
Fig 3 Crime Monitoring
Fig 4 Crime Investigation & Reporting
The MapServer is a system for developing web-based GIS applications. The core of the system is a Common Gateway Interface (CGI) application that allows developers to rapidly build and deploy web applications based on GIS databases using simple text-based configuration and presentation templates. The PostgreSQL [5] database server has been used to manage the attribute data and multi-media content. PostgreSQL is an Object-Relational DBMS, supporting almost all SQL constructs, including sub-selects, transactions, and user-defined types and functions. The database consists of tables that hold all the attribute data and spatial data.
The PostGIS adds support for geographic objects to the PostgreSQL object-relational database. In effect, PostGIS "spatially enables" the PostgreSQL server, allowing it to be used as a backend spatial database for geographic information systems (GIS). Real time update of authorized users is also made possible. The users can access the system by web interface(PHP) that enables online access to the GIS layers and attribute information.
