Internet Mapping GIS By Jane E. Goodman Web based GIS applications deliver customized maps on demand to an eager Internet audience. No longer the exclusive domain of specialists, spatial tools such as buffer zoning, routing and geocoding are available to anyone with a browser and Internet access. Users can retrieve satellite imagery, determine voting districts, or check property assessments, highway conditions and crime activity. The complex products that power map-based web sites are evolving toward easier implementation as well as offering improved performance and new capabilities. Additionally they are influenced by the Open GIS consortium which is developing standards for web mapping applications. You can check the current status of many different web mapping products in meeting these standards at their website. www.opengis.org/techno/conformance.htm#products We chose five companies offering some of the latest features available in the Web Mapping arena. Intergraph GeoMedia WebMap When Intergraph Corporation introduced GeoMedia Web Map™ in April of 1997 it supported only MGE and MicroStation data despite its "GeoMedia" appellation and maps were generated in exclusively ActiveCGM format. The latest release,.GeoMedia Web Map 4, is an open GIS solution fully integrated with the GeoMedia product line. It uses no proprietary languages or data formats and reads MGE, FRAMME, ARC/INFO, ArcView, MicroStation®, IGDS, Field View, MapInfo, AutoCAD, Oracle Spatial Cartridge/Spatial Data Option, Oracle 8i, Microsoft SQL Server, Microsoft Access and ODBC data directly, without translation. Available in 2, 12 and 96 map server configurations, GeoMedia Web Map applications are developed using Microsoft's Internet Information Server (IIS) Active Server Page (ASP) technology. Features include spatial and/or attribute analysis and filtering on GIS data, on-the-fly transformation of disparate data sources with varying source projections/datums into a single display, scale-based display of features, and the creation of customized tool tips and actions. Raster imagery in any of the twelve different formats supported by GeoMedia can be displayed as a backdrop. Maps can be generated in ActiveCGM or JPEG format. While JPEG maps are easily viewed on any browser, an ActiveCGM or "smart map" enables interactive map display. Hotspots that change color as the mouse moves over them and ToolTip text display for dynamic labeling add intelligence to the map. Since ActiveCGM maps contain layers that can be turned on and off, the display of map features can be controlled on the client side without downloading a new map from the server. Additionally, multiple ActiveCGM files can be merged to display a single map so the entire map doesn't have to be regenerated on the server side when a user wants an additional feature not included in any existing layer added to the current map display. True Type fonts and symbols and Unicode or Multibyte character sets are also supported. The Web Map Administrator is a GUI interface used to create a map definition file that describes map features and associates them with display rules including tool tips and hotspot actions. Features are grouped into display sets associated with threshold values for determining the scales at which the features in the display set turn on and off. ASP's, VB Script and Java Script and Java applets can be used to code the hotspot actions. Intergraph will soon make available for download at its website a visual authoring / application generation utility. It will be delivered as a GeoMedia custom command that allows you to set up the contents of a map window (including all features classes, queries, spatial queries, legend styles, etc.) and quickly produce a GeoMedia Web Map implementation. The utility is not included in the initial Web Map 4.0 release but will be posted at www.intergraph.com/gis/gmwm when it is released. Web Map generates maps live, on-the-fly from active projects with no translation to a common format required. A new option is to export selected project warehouses to specially indexed SmartStore warehouses. Performance can be up to ten times faster. The downside is that the data is a static view of the project at the time the SmartStore warehouse is created. It is possible to access data from the SmartStore and native connection to improve performance while still using the "live" data when necessary. GeoMedia WebEnterprise is a deluxe version of Web Map that includes samples of four typical spatial analysis applications crime analysis, routing, rezoning notification and site selection as well as additional Web Map automation objects. The applications span common customer requirements for spatial data and can be implemented out of the box or serve as prototypes for other enterprise-specific applications. Full documentation is included with each application.