A beginner's guide to building an intranet-based GIS

The Data
To begin, an organization must have some data—raster, vector or some combination—that it needs to distribute across the enterprise. It may also need to distribute data to the extended enterprise which may include vendors and partners. Ideally this data will be up-to-date, managed by an Open GIS Application/Database, and pertinent to the requirements of the user community. Since the requirements of each enterprise are unique, it is vitally important that database design, application development, and long term-data maintenance requirements be adequately addressed in the implementation plan.

The Data Server
AM/FM/GIS data is typically stored on dedicated servers utilizing either Windows NT or Unix operating systems. The specifications for these servers will vary depending on the legacy systems, data capacity requirements, number of concurrent users, downtime restrictions, and security concerns. The data server must be able to service the enterprise during peak usage times without being dramatically under-utilized during normal operations. The data stored here will be maintained by specialized applications such as Intergraph Corporation’s MGE, ESRI’S ARC/INFO, or Smallworld GIS to name only three, which are designed specifically to create and maintain the integrity of spatial data. These specialized applications should also be web-enabled, i.e., they should have an add-on component that will allow the GIS database to understand and fulfill the requests received from the Web Server.

Web Server Armlication
The Web Server Application’ job is to take requests from the Client, pass that request on to the GIS database, receive and repackage the GIS database response” Web-Ready,” and pass it back to the Client. Web Server Applications are typically tightly integrated to the parent application maintaining the spatial database on the Data Server.

The power of the Web Sever Application can be enhanced with a closely integrated Data Server Application. Intergraph’s GeoMedia Web, SmallworldWeb, ESRI’S MapObjects Internet Map Server (IMS), and Autodesk World, are all examples of applications that have been developed with specific GIS products in mind. These Web Sever Applications manage the instructions between the client requests, formatting that request into commands that the Data Server understands. When the Data Server responds, the Web Server formats the response to be read by the Client Application.

Web Server
Web Enabled GIS applications require no special equipment for serving data over an Intranet . A typical web server configuration is sufficient for GIS Web Server Applications. Since all of the GIS processing is handled by the Data Server the Web Server simply manages the flow of data between the Client and the Data Server. The primary consideration is that the server and network be sufficiently sized to handle peak-time traffic.

Client Amlication
The Client Application is simply a web browser enhanced with a specialized plug-into enable the browser to display the spatial data. Generally the plug-in software is free to download making the GIS data very accessible from any location with access to the World Wide Web.

Client
Generally, any PC that is capable of running today’s office software is capable of accessing and displaying Web enabled GIS data. The only requirement is access to a TCP/IP network.

Technology available today
Each of the major vendors that supply AM/FM/GIS applications and systems offer web products to enhance their core functionality. The web applications offered by five of the major AM/FMIGIS vendors are discussed below.

Smallworld. Plc, SmallworldWeb
http://www.smallworld.co.uk, http://www.smallworld.co.uk/technology/smwrweb.asp

A tool to publish Smallworld GIS data. This tightly integrated application allows Smallworld GIS customers to distribute intelligent spatial data across the Internetflntranet. It is basically a development tool to allow customers to customize and control what data to distribute. The application utilizes Smallworld’s MAGIK development language.

SmallworldWeb includes Dispatcher, which provides automatic load balancing across any number of Smallworld Application Servers. Dispatcher routes information requests from the client to the Application Server, and routes the correct information back to the client. SmallworldWeb is a good tool for existing Smallworld customers, however, it is limited in that it can only operate on Smallworld GIS databases. It runs on both Windows NT and Unix platforms.

lntermaph Corporation, GeoMedia Web
http://www.intergraph.com, http://www.intergraph.com/software/geo_map/geo_web.asp

Intergraph has challenged its competitors by offering one of the first” Open GIS” applications. GeoMedia Web Map can access native forms of both Intergraph GIS products—MGE and FRAMME-and the graphic engine for these products—Bentley Systems MicroStation. GeoMedia can read ESRI’S ArcView and ARC/INFO products. Data Servers for MapInfo and

AutoCAD products are in the development stages.
Databases supported include Oracle SDO and Spatial Data Cartridge, as well as Microsofl Access. Support for Microsoft SQL Server is in the development stage.

GeoMedia Web Map creates smart, vector-based maps on the fly, directly from a live, operating GIS database. It utilizes Intergraph’s open ActiveCGM format, a compact, customizable format that is ideally suited for delivering vector data over the Internet/Intranet. Using these smart vectors to store features, the product creates very compact, highly intelligent maps. The true benefit of GeoMedia Web Map is its ability to access multiple databases in native form. As Intergraph continues to grow this technology, a truly” Open” solution may exist. It runs only on the Windows NT Operating System.

ESRI, MaPObiects Internet Map Server (IMS), ArcView IMS
http://www.esri.com/software/internetmaps/index.html

Map Objects IMS is a powerful toolkit for developing Internet/Intranet applications for existing ARC/INFO, ArcView customers or those customers with ODBC compliant databases. Utilizing industry standard development languages such as VB, Delphi, Powerbuilder, or Visual C++, an organization can quickly publish their ArcView and ARC/INFO datasets over the Internet/Intranet. It runs on both Windows NT and Unix. ArcView IMS is an extension of the core ArcView application. Development languages are Avenue with a Java wizard supplied with the product. Any View created with ArcView GIS can be served over the Internet/Intranet.

Bentley Systems
http://www.bentley.com/products/mstation/j/

MicroStation/J is professional enterprise engineering modeling soflware integrating modeling with engineering and business applications. MicroStation/J is designed for Internet or corporate intranets and supports the entire life cycle of products and assets, from conception to construction and deployment. The MicroStation/J JMDL Virtual Machine, which includes the Sun Java Virtual Machine, enables users and developers to use the power of Java to create platform-independent applications. A seamless integration with enterprise systems is offered by the ability to run Java-based business applications within the engineering environment.

AutoDesk Corporation, AutoDesk MapGuide
http://www.autodesk.com/solution/gis/

AutoDesk has entered the AM/FM/GIS market aggressively with their three application suites of geographic maintenance, mapping, and viewing tools. Through the collected use of AutoDesk MapGuide, AutoCAD Map, and AutoDesk World, AutoCAD users have a full set of tools to create, maintain, and distribute data across the Internet/Intranet.

AutoDesk MapGuide
Map Guide contains three main components:

Autodesk MapGuide Author
Autodesk MapGuide Author is an authoring tool that lets you create maps for viewing and distribution over the Internet/Intranet. It creates a custom intelligent map document known as a Map Window File (MWF) for distribution.
The Autodesk MapGuide Server
Autodesk MapGuide Server is used to broker requests and delivers maps and map data over Internet/Intranets to users who have installed the free Autodesk MapGuide Viewer. Autodesk MapGuide Server is a scaleable, fault-tolerant, 32-bit, multithreaded architecture that runs as a service under Windows NT.
The Autodesk MapGuide Viewer
Distributed to end-users free of charge, the Autodesk MapGuide Viewer is an intelligent client that enables non-technical users throughout the enterprise to interact with simple or complex maps, collapse or expand themed layers, make queries, create dynamic buffering zones, run custom reports based on selected objects, and print to scale. Autodesk MapGuide Viewer utilizes Netscape API, ISAPI, and standard CGI interfaces to integrate with Netscape, Microsoft, and other Web server products.

AutoCAD Map
AutoCAD Map software is the Autodesk solution for precision mapping and GIS analysis in the AutoCAD environment. It delivers the complete AutoCAD Release 14 toolset, plus specialized functionality for creating, maintaining, and producing maps and geographic data.