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deegree - Components and Framework for SDI
Dr. Markus Lupp
lat/lon, Kupang, Timor, Indonesia
markus.lupp@lat-lon.de

deegree is a Java-based Open Source / Free Software framework for the implementation of Spatial Data Infrastructures. It contains the services needed for SDI (deegree Web Services) as well as portal components (deegree iGeoPortal), mechanisms for handling security and access control issues (deegree iGeoSecurity) and storage / visualization of 3D geodata (deegree iGeo3D).

deegree is based on the standards of the OGC and ISO / TC 211. Presently it is the most comprehensive implementation of those standards in one Open Source framework. The framework is component-based to a high degree, allowing the flexible creation of solutions for a wide variety of use cases. It is published under the GNU LGPL.

COMPONENTS
deegree comprises five groups of components that are briefly described in the following.

DEEGREE WEB SERVICES
These are the base components of any SDI. The list of implemented OGC Web Services includes WMS, WFS, WCS, CSW, Gazetteer, SOS, WPS and WTS/ WPVS. Besides, two security services (WAS/WSS), a printing service (WMPS) and a service monitor (owsWatch) are available.

DEEGREE IGEOPORTAL
iGeoPortal has a modular structure and is able to display maps, support searches using geographic identifiers, search for datasets using metadata, allow for controlled access to OGC Web Services and display of 3D geodata.

deegree iGeoPortal itself consists of different modules for separate, but combinable, functionalities. The list of modules includes: map, download, gazetteer, catalogue, security and 3D.

DEEGREE IGEOSECURITY
deegree iGeoSecurity can be used to define access mechanisms using authentication & authorization mechanisms, secure connections and filtering of geodata. A database for managing users, user groups, roles and rights called deegree U3R is the core component of the security components.

DEEGREE IGEO3D

deegree can be used to store 3D geodata such as digital terrain and building models in file-based systems and relational databases. Using different deegree web services, this data can be queried and displayed.

DEEJUMP
Using deegree components, the Open Source desktop GIS OpenJUMP (Java Unified Mapping Platform) was enhanced to support WMS and WFS. A number of additional modifications and extensions was also developed.

OVERALL ARCHITECTURE
The different deegree components can be combined with each other or with other standard-compliant software. iGeoPortal with its different modules

Open Source
CityGML A GML application schema for city models CS-W Catalogue Service - Web. An OGC standard for access to metadata GML Geopraphy Markup Language. An OGC standard for XMLbased encoding of geospatial data.

GNU LGPL
The library or lesser GNU public License. A Free Software license developed by the Free Software Foundation (http://www.fsf.org) OGC The Open Geospatial Consortium, an international standardization consortium for geospatial applications.

OWS OGC Web Services
SDI Spatial Data Infrastructure

SLD Styled Layer Descriptor. An XML grammar for styling information. In version 1.1.0 SLD is split into Symbology Encoding and SLD.

SOS Sensor Observation Service. A standard of the OGC for access to time-dependent sensor data U3R User Rights, Roles and Resources. A database schema used by deegree for storing access control information.

WCS Web Map Service. A standard of the OGC for data access (mainly raster data).

WFS Web Feature Service: A standard of the OGC for data access (vector data) WFS-G Web Feature Service - Gazetteer profile. A WFS specialized on placenames and addresses.

WMS Web Map Service. A standard of the OGC for data visualization. WPS Web Processing standard. A standard of the OGC describing a service able to process geospatial data.

WTS
Web Terrain Service. A standard by the OGC describing access to 3D visualizations using pictures. Newer version of thes specification are sometimes called Web Perspective View Service (WPVS).

XPlanGML A (German) GML application schema for urban and town planning information. acts as a web-based client to the different Web Services. Alternatively, dee- JUMP can be used to access WMS oder WFS services. If needed, security management can be implemented using iGeoSecurity. deegree can access different data sources, e.g. PostgreSQL /Post- GIS or Oracle databases, shapefiles, all kinds of relational databases using a deegree-specific spatial extension and different kinds of image formats such as PNG, GIF, JPEG or (Geo)TIFF.

APPLICATION AREAS
deegree technology can be used in all areas that benefit from SDI approaches. The three major application areas for deegree in the future will be urban and town planning, environmental information systems and natural disaster management, in more detail described in the following.

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