The CANRI technology framework is based
on the Integrated Community Mapping and Information Support System
(ICMISS), which pioneered distributed web mapping with its release
in 1998-99. ICMISS has been an influential model for the development
of international standards for web mapping by the OpenGIS
Consortium. As mandated in the
CANRI Collaboration Principles, CANRI is now deprecating its ICMISS-specific
services in favour of recently agreed standards including the OpenGIS
Web Map Server specification
(WMS1).
Applications
CANRI applications are built on the Map
Broker application server from Social
Change Online. The Map Broker uses Java Server Pages (JSP)
templates, a widely accepted technology for high-performance serving
of dynamic content over the web. The JSP files reference a library
of JavaBeans components to
perform mapping and other functions. Application parameters are stored
separately in XML files, so that
applications can be reconfigured to meet multiple purposes. For most
applications additional software has been developed to provide specific
functionality in the user interface, but all work with the same underlying
infrastructure. See the CANRI home page for
examples of CANRI applications.
Web developers outside the CANRI program can build their own applications to
access CANRI's data servers using any software that can act as a client to an OGC Web Map Server (see the
list of implementations of
OpenGIS interfaces). CANRI is committed to upgrading our data servers to
support OGC specifications as needed, so please
contact us if you are interested in
this option.
Catalogues
CANRI applications like the NSW
Natural Resource Atlas use the NSW Natural Resources Data Directory
(NRDD) as a catalogue
to discover and access online datasets. In addition to the ANZLIC-standard
metadata accessible to NRDD users (see NRDD
Technical Details), CANRI applications use metadata extensions
designed specifically for online data access. The format of this metadata
and the interface used will change to comply with the OpenGIS Catalogue
Interface specifications.
This will enable CANRI applications to make use of other catalogues
of data and services as they emerge.
Operators/models
The CANRI framework can make use of independent information services
available on the web. Currently, a geographic projection service
is built in to the CANRI application server. This area of the
architecture is expected to grow with the availability of gazetteers,
address geocoding, image processing and other services.
Data repositories
The CANRI framework supports access to a wide range of remote data
servers over the web. Any data server which complies with the OpenGIS Web Map Server
specification
is supported.
A growing number of GIS vendors are now providing such products -
see the
list
of implementations of OpenGIS interfaces.
Low-cost bridges can be built for most data sources.
Data in shapefile
format (supported by ESRI products)
can be served with the freely available MapServer package.
MapServer also supports many image formats.
The MapWrap wrapper makes MapServer WMS-compliant and is
needed to link a MapServer data server into CANRI applications.
Alternatively, you can use the freely available DSLITE
Perl script, which supports GIF images, comma-delimited ASCII text and ODBC
point data sources like Microsoft Excel, Access, SQL Server and other database products.
DSLite is not (yet) OpenGIS WMS compliant, but it supports CANRI's legacy
CSGI protocol.
Low-cost
CSGI
wrapper scripts are also available for
MapInfo,
JDBC and
Genamap data servers.
Technical Workshop Presentations
|
