INTERNATIONAL INSTITUTE FOR GEO-INFORMATION SCIENCE AND EARTH OBSERVATION Towards quality-aware Infrastructures for Geographic Information Services Richard Onchaga M. onchaga[at]itc.nl

Outline: Background Geographic information Exploiting location to create value GI market dynamics Towards open access to GI Motivation Objective Approach

Background: Geographic information […] information that references a geographic location e.g. topographic maps, census data, zip codes, and street addresses. Used for managing environment, resource allocation, navigation, military applications, etc.

Background: Exploiting location to create value […] integrate information from different sources to create new information for new applications […]

Background: GI Market dynamics Market pull Increased awareness of positive externalities of GI More integration of GI across domains/applications Increased demand for GI Growing non-expert GI market e.g. location based services Technology push Earth observation, GPS, Aerial Mapping technologies & GIS, Image processing systems: Less costly & more efficient data collection & processing Internet/Web: Improved chances for information sharing => SDI SOC, Web services, Wireless & mobile technologies: New opportunities for location based services & information integration => GI services

Towards Open Access to GI (TOAG) Two paradigms: Spatial data infrastructure (SDI Geographic information web services (GI services) and GI service composition:

TOAG: Spatial data infrastructure /1 […] a relevant collection of technologies, policies and institutional arrangements that facilitate the availability of and access to geographic data [….]

TOAG: Spatial data Infrastructure /2 Local, Provincial & National Government User Communities Transportation, Utilities & Infrastructure Management Research Groups Security & Emergency Data Producers Commercial & Professional Users SDI Local data sub-national data Project specific data ??? Citizens Standardized data descriptions Search engine Communication network Exchange agreements

TOAG: Spatial data infrastructure /3

TOAG: GI services […..] geoprocessing services which are published, and can be located and invoked over the web to access and process geographic data from different sources …. and can be composed to create and deliver sophisticated services & customized information Extends the SDI Based on open industry and IT standards Standardization led by the Open Geospatial Consortium (OGC)

TOAG: GI services architecture

Motivation: Composition of GI services (Example) Reprojection Service Web Coverage Service Web Coverage Service Portrayal Service Portrayal service assembles orthoimage from several imagery services Reprojection servicereprojects the image from one coordinate system to another one Vector Data Provider Service Vector data provider service returns a certain layer at the extent specified Overlay Service Overlay service overlays the input image and the vector data and sends the overlay to the client To Client Web Coverage Service (Adopted from (Alameh, 2001))

Motivation: Conventional GI service composition architecture/1

Motivation: Conventional GI service composition architecture/2 Service composition intelligence on client side Simple mediator (registry) – query & search Not quality-aware Costly & complex process of GI service composition/developing GI applications

Motivation: Proposal for GI Middleware GI middleware to provide dedicated functionality for quality-aware composition of GI services Functionality to be exposed as generic services to application components

Motivation: Positioning the GI middleware

Motivation: Benefits of GI Middleware Business justification Flexible & efficient business processes – easy, fast, & reliable re-use of existing resources; Mass customization or service-differentiation Design benefits: Less complex & less costly GI application design process in the long run as a result of: Quality-aware composition transparencies; Re-useable GI middleware services; Extensible GI middleware

Objective: General objective To design and validate an architecture for the GI middleware system which facilitates quality-aware composition of GI services

Objective: Specific objectives 1.To define concepts for quality in distributed service-oriented processing of geographic information 2.To derive requirements that will guide the design of the GI middleware system 3.To define an architecture for the GI middleware system 4.To validate the architecture by using typical use cases

Approach: General Approach

Thank you !