Geospatial Systems Architecture
Todd Bacastow
GIS Evolution
http://wiki.gis.com/wiki/images/8/81/FallSDS11Fig2-1_Evolution.jpg
Number ofUsers Internet
ViewerComponentHand-heldDesktop
Professional
Functionality
GIS Users
Market Forces• Integrating spatial data analysis and map
visualization into key business applications • Moving and consolidating spatial data • Moving client/server mapping applications to the
web and looking to web services
What is an architecture?
• There is no universally agreed definition• A system architecture defines the structure and/or behavior
of a system• Best be thought of as a representation• It is also a process because a sequence of steps• It can also be a discipline
Analogies
• Consider a community that maintains an infrastructure for a public service to homes and businesses. This infrastructure might include:– Electricity producers– Drinking water purification and distribution– Sewage treatment– Other waste disposal– Natural gas distribution– Public transport– Cable television and telephones– Roads and toll ways
Evolution• business processes• systems structure• technical framework• product technologies
Evolution
business processes + systems structure + technical framework + product technologies
GIS Configuration Alternative:Stand alone
business processes + systems structure + technical framework + product technologies
GIS Configuration Alternative:Connected Desktop
business processes + systems structure + technical framework + product technologies
GIS Configuration Alternative:Centralized Configuration Alternative
business processes + systems structure + technical framework + product technologies
GIS Configuration Alternative:Centralized Configuration Alternative
business processes + systems structure + technical framework + product technologies
GIS Configuration Alternative:Federated
business processes + systems structure + technical framework + product technologies
GIS Configuration Alternative:Mobile
business processes + systems structure + technical framework + product technologies
Internet/Web
Web Server
DatabasesDatabases
BrokerBroker
BrowsersBrowsers
Web
ApplicationsApplications
business processes + systems structure + technical framework + product technologies
Cloud Architecture Building Blocks
GIS Portal
GIS Portal
• Network architecture
(Distributed)
• Loosely Coupled
• Internet Standards
• Many GeoServices
• Many Clients
• Metadata Servers
• Open / Interoperable
• Full GIS capabilities
GIS Users
GIS PortalMetadata
Server
Searc
h Cat
alog
and
Fin
d
Searc
h Cat
alog
and
Fin
d
Publish GIS Data & Publish GIS Data & ServicesServices
Document in CatalogDocument in Catalog
Connect and U
se
Connect and U
se
Checkout and U
se
Checkout and U
se
World Wide Web
Author, Manage, Serve Geographic Information Collections
Author, Manage, Serve Catalogs
business processes + systems structure + technical framework + product technologies
How? • Consume and expose Web services for:
– Mapping
– Metadata
– Data sharing and distribution
– Geoprocessing
• Provide standard services and components for web developer
(.Net, “generic XML/SOAP”, or Java API’s)
GIS Services Enterprise
Web Server
Databases
Broker
Browsers
Web
Applications
Services
business processes + systems structure + technical framework + product technologies
Integration
business processes + systems structure + technical framework + product technologies
Another view of architecture• Enterprise• Information• Computational• Engineering• Technology
System Architecture• ISO Reference Model of Open Distributed Processing
(RM-ODP) – Enterprise Viewpoint:
• It is directed to the needs of the users of an information system.
– Information Viewpoint: • It focuses on the information content of the enterprise.
– Computational Viewpoint: • It deals with the logical partitioning of the distributed applications independent of any specific
distributed environment on which they run.
– Engineering Viewpoint: • It addresses the issues of system support (platform) for distributed applications.
– Technology Viewpoint: • The technology model identifies possible technical artifacts for the engineering mechanisms,
computational structures, information structures, and enterprise structures.
Architecture Development
.
Steps
• Defining Architecture Requirements. – to enable the system to meet the community’s goals and objectives.
• Defining a Candidate Architectures.– to evolve an architecture gradually.
• Defining Enterprise Architecture. – integrate it into an enterprise architecture model.
• Defining Reference Architecture.– a working example designed and proven for use in by the participants
• Validating a Reference Architecture.
Timing is everything
Readings
• GIS software architectures– http://wiki.gis.com/wiki/index.php/GIS_Software_
Technology
• ESRI GIS products– http://wiki.gis.com/wiki/index.php/GIS_Product_
Architecture