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A Comparative Assessment of Internet GIS Server Systems
Benchmark design
The research performs a practical experiment to assess the operational use of specific software for a certain task. Spatial data of Phuket has been taken to develop as same input data. The network conducted on an isolated LAN connecting a client machine to a server machine running the tested application. The web server was deployed using Internet Information Services (IIS) with Java Virtual Machines (JVM). Additional, Apache Tomcat v3.2.2 has been run as an application server hosting for MapXtreme.
Figure 4. WebGIS Applications development flow diagram.
This experiment is only one task of the WebGIS applications testing, which the specific system environments were used. In reality however, data sources may differ with the variety of WebGIS applications and system environments as well as each software package may behave differently. For shortly discussion on this task cause of the time limited, the research still going on for the software benchmarking in various aspects of webmapping application.
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System architecture overview
In order to test the WebGIS software, it is necessary to limit as much as possible external factors that influence their performance. To standardize the server-side of the computer network configuration, the system requirements of the three WebGIS software packages have to be compared regarding to their operating system (OS) dependency and the server software dependency. In term of Internet, the web mapping applications have to deal with the variety of the OS. The compatible of OS in both Client and Server side have to be concerned.
Table 1. Supported OS for client-server
| Product Name |
Client OS |
Server OS |
| |
Win NT |
Win 9x |
Mac |
Unix |
Win NT |
Win 9x |
Mac |
Unix |
| MapXtreme |
Y |
Y |
Y |
Y |
Y |
Y |
Y |
Y |
| ArcView IMS |
Y |
Y |
Y |
Y |
Y |
Y |
N |
Y |
| MapServer |
Y |
Y |
Y |
Y |
Y |
Y |
- |
Y |
- Input and output of geospatial data
- File formats
Before developing the webmap application, WebGIS have to be able to deal with the several of data source. Then the abilities to access to the general geo-data as well as projection and co-ordinate transforming have to be compared. The entail of data sources that provide the GIS information on the web, ArcView IMS is developed by ESRI and can native support the ArcView file format certainly. The additional support files can be imported by means of the ArcView program. MapXtreme, generally, have defined as the map definition in .mdf file format that can be generated from various data source such as MapInfo tab file, ESRI shape and GeoTiff Raster. MapServer also use the shape file as the default vector formats supported. For the other source files, MapServer use the OGR Simple Features Library to access to a variety of file formats including MapInfo file, Microstation DGN and others.
- Distributed the Geospatial data to the public
Basically, WebGIS generate map in typical JPG and GIF raster file formats that will be able to open in any standard web browsers. For the vector map, MapXtreme offers MapXtreme JavaBeans that allow you to embed live vector maps in a Java applet or application and display maps from these vectors. MapServer also support for tiled raster and vector data (MapServer, 2002, URL). Only the ArcView IMS that cannot support with vector display.
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