Web-GIS services is one of the most growing sectors in the Geographical Information
System (GIS) science. Its popularity mainly resides in an easy-to-use interface for
non-specialists to access geographical information for decision making.
In most cases these web applications are focused on distributing geospatial
information on the Internet in a “static” way: users can access and navigate the
different maps, build combinations of layers and print the results. More “dynamic”
applications are now requested by different specialists: geologists ask for
digitalization tools, hydrologists ask for watershed analysis tools, and so on.
Providing these kinds of geoanalysis tools requires full access to typical GIS
capabilities like map generation, map editing and map analysis.
In the FOSS (Free and Open Source Software) world two software packages are widely
used for building Web mapping services and computing geographical analysis:
1.Chameleon
(http://www.dmsolutions.ca/technology/chameleon.html)
is a highly customizable and adaptable environment for deploying and managing Web
mapping applications. By using MapServer
(http://mapserver.gis.umn.edu/) as the backend mapping
engine that generates map images, manages mapped data and handles all of the
geographic processing, Chameleon provides a tag system similar to HTML (Hypertext
Markup Language) to incorporate the required mapping functionality into your current
HTML page.GRASS (Geographic Resources Analysis Support System,
http://grass.itc.it/index.php) is a GIS used for
geospatial data management and analysis, image processing, graphics/maps production,
spatial modeling, and visualization. It provides import/export capabilities for
extensive data formats (by using the GDAL/OGR libraries and specific commands) and
data reprojection (by using the PROJ library).
A new procedure for linking these two geospatial Open Source software packages is
presented. Such a procedure allows for the development of custom Chameleon
functionality (in the form of Chameleon “widgets”) to seamlessly access GRASS
functionality.
Due to the FOSS environment of both of these software packages, this is a free,
transparent and highly customizable solution for developing “Web-GIS analysis tools”.