The development of open source software going rapidly, and many variants emerge quickly. The fact that open source software tend to be free and easy to obtain, the main attraction that support the popularity of this software. So many, it's no wonder that the prospective user and is confused to choose which software to use. One of the AOS is quite popular in the online mapping world is MapServer. MapServer is an example of a fairly successful AOS project was supported by grants and loyal community.
MapServer is one of the online mapping application (web GIS) developed by the University of Minnesota, NASA, and the Department of Natural Resources Minnesota (Minnesota Department of Natural Resources). MapServer is an open source application which means it can be distributed for free along with the programming source code if you want to develop further. MapServer can run on multiple operating systems are Unix / Linux, MacOS and Windows. Features supported by MapServer is:
- Vector Format: ESRI shapefile, ESRI ArcSDE
- Raster Format: TIFF/GeoTIFF, GIF, PNG, ERDAS, JPEG, EPPL7
- Quadtree spatial indexing for shapefile
- Can be fully customized to produce the desired results
- The selection of features using item / value, point, area or other features
- Supports TrueType fonts
- Supports OpenGIS
- Supports raster and vector data integration (for data presentation)
- Legend and scale automatically
- Support the development of thematic maps online
- Labeling features
- On-the fly configuration
- On-the-fly projection
To run and display maps generated by MapServer, requires two files which HTML File and Map File. File folder contains configuration map presentation written in its own language and syntax. This information is then processed and presented by the MapServer program. While the HTML file used to format the presentation of results (map). HTML files can be either plain or HTML template inserted MapServer syntax or HTML files inserted PHP / MapScript.
MapScript is a PHP module that can perform operations on spatial data are included in the process of spatial data, the data reprojection, and other operations. Module PHP / MapScript was developed by DM Solutions (http://www.dmsolutions.on.ca/).
Before creating GIS web applications using MapServer thing to note is that MapServer file storage architecture and GIS data. In general, there are three categories of data held are:
- MapServer File
Map file and PHP/MapScript
- HTML File dan image/graph
Files and images that are included
- GIS data
Vector and image data (raster) which used
Web GIS is sufficient for further development. With this application, users can publish and professional GIS data and GIS analysis results through web media / interactive internet. There are some that must be considered in the development of web GIS applications. Be aware that underlying it all is the advancement of Internet technology and infrastructure. Applications are quite sophisticated but not supported by an adequate Internet infrastructure will result in products that are not significant anymore.
Web GIS Application Development Design
Opensource application is an application that is quite difficult to learn. However, compared to the commercial applications that are quite expensive, alternative applications can be implemented without the use of a large fee. Commercial applications was still difficult both in terms of management and technical aspects. Before implementing web-GIS, there are some things to note are:
- Compatibility data. Although many apps that claim to use multiple data formats, it should be seen that often by adding additional applications (third-party software) can affect the speed of data access.
- User profile. Users should be able to be identified, who can have access to this application and who is not. What facilities are available and who can take advantage of these facilities.
- The ability to customize the client side. This is important because the ability to do the customization on the client side we do not need to make changes and additions to the server because the server can result in performance degradation.