"a substructure or underlying foundation; esp., the basic installations and facilities on which the continuance and growth of a community, state, etc.depends as roads, schools, power plants,transportation and communication systems, etc
What is Information Infrastructure?
a shared, evolving, open, standardized, and heterogeneous installed base"– Shared resource, foundation for (all) the activities in a community– Evolving continuously– Open in the sense of lack of borders (number of components, users,contributors, developers, .. no beginning/ending)– Heterogeneous – components (HW, data, users,sub-structures ..) are of different kind and characteristic– Standards – prerequisite for combining the heterogeneous parts– Installed base – what is existing and being used
What is spatial information infrastructure?
‘infrastructure for spatial information’means metadata, spatial datasets and spatial data services; network services and technologies;agreements on sharing, access and use; and coordination and monitoring mechanisms, processes and procedures, established,operated or made available in accordance with this Directive;
What is a Geographic information system?
a set of tools that captures, stores, analyzes, manages, andpresents data that are linked to location(s).
– designed for a specific purpose (use cases) and a specificuser group
– well managed (configuration, versioning, release cycles,data quality, ..)
– typically part of an information infrastructure(networking with other components..)
What is an SII/SDI ?
..base collection of technologies, policies and institutional
arrangements that facilitate the availability of and access to spatial data.
A (technical) standard is..
an established norm or requirement about technical systems.It is usually a formal document that establishes uniform engineering or technical criteria, methods,processes and practices.
Why use Standards?
• Basis for interoperability of independent components
– Optimized value chain
– Open standards avoid vendor lock-in
• Reduced costs for implementing interfaces
– Less customization
- Improved reusability
• Enlarges both user communities and developer communities
– Improved quality (fastermaturing process
– Less costs per unit
Basis of communication in the Web (between server & client)
supports many commands, most important:
•GET –requests a representation (e.g. digital copy) of the specified resource
•POST –submits data to be processed
•HTML document are predefined on server
•Web server sends out documents on request
•HTML documents are created on request
•Often: data to represent is stored in DB
Commonly used today
Language for communication between server & server
Used to store data
software and hardware independent
xml tags are not predifined
can be defined in a schema
xml based languages for geodata
–Geography Markup Language (GML)
–Keyhole Markup Language (KML)
–OpenStreetMap Format (OSM)
–City Geography Markup Language (CityGML)19
•Describes structure of XML documents (= instances)
•Stored in XML Schema Definition (XSD)
filecan be used to formally define new languages/ models–(e.g., GML, KML, SVG etc.)
Motivation for Web Services
–Interaction between applications over the Web
–Web Services can convert applications into web-applications (or: Web accessible API)
–Not only a Web of documents Web of services!
–Automated Information Exchange between applications!
What is a Web Service
A Web service is a software system designed to support interoperable machine-to-machine interaction over a network.
It has an interface described in a machine-processable format (specifically WSDL).
Other systems interact with the Web service in a manner prescribed by its description using SOAP-messages,typically conveyed using HTTP with an XML serialization in conjunction with other Web-related standards.
WSDL := Web Service Description Language
•Originally: Simple ObjectAccess Protocol
•Today: not an acronym anymore; just SOAP
•Evolvement of remote procedure calls through plainXML (so-called: XML-RPC)
•Usually used over HTTP
SOAP Basic Structure
Header [optional] Includes meta information (security, transaction number...)
Body [required] Includes the actual message payload
Fault [optional] Contains errors and status information
System Architecture (definition)
– System: A collection of components organized to accomplish a specific function or set of functions.
– Architecture: The fundamental organization of a systemembodied in its components, their relationships to eachother, and to the environment, and the principles guiding its design and evolution
System Architecture, Main Purposes of an Architectural Description
Facilitate planning, managing, and executing the activities of system development
• Documenting decisions on high level design issues
• Reusing design patterns
• ..– Communication amongst the system stakeholders
System Architecture, Typical Stakeholder‘s concerns
• Certain functionality– …
• Non functional requirements
• Infrastructure as a Service (IaaS)
– Virtualized and dynamically managed (elastic) IT infrastructure
– On demand provisioning of resources (server, storage)
– Delivers computational infrastructures as services over the network
• Platform as a Service (PaaS)
– Software development and deployment platform
– Quality of Service, QoS (scalability) managed by cloud provider
• Software as a Service (SaaS)
– Dyncamic Software and data provisioning (outsourcing, on-demand)
– Allows pay-per-use revenue models
Chracteristics of the cloud based architecture
• Reliability, SLA
How does OGC work?
•Consensus process–that is reflecting a common understanding of requirements and a membership driven process.
•Formalised standards development process
–based on commonly agreed, structured and well defined policies and processes.
•Making use of innovative processes
–for testing, verifying and documenting user requirements
OGC Document Types
•Public Change Request
•Best practice document
OGC Web Services Architecture
•Defined on Internet standards: URLs, HTTP, XML
•message-oriented, stateless, common elements
•hardware and software neutral
•Closely based on ISO 191XX series of standards
•Services chaining to support workflow
Topics are organized in working groups
–Ubiquituous public access
Geography markup language
•a modeling language for geographic information
•an encoding for geographic information
•designed for the web and web-based services
•GML is an OpenGIS® Implementation Specification–Current version is 3.2.1
•GML is also published as ISO 19136
GML enables a vendor-neutral exchange of spatial data
•spatial and non-spatial properties of objects
•Web Service for maps as images on the web–HTTP & XML–JPEG, PNG, GIF
•Maps are organized as (nested) layers
•Layers from different WMSs can be overlayed
•Current version 1.3.0
•Published as ISO 19128
•Web Services for feature data on the web–HTTP & XML
–Features can be queried by featuretype
–Query is expressed through Filter Encoding (ISO 19143)
•New version 2.0.0–Previous version
Web Service for coverages on the web
–Examples are TINs & GRIDs (see GML Application Schema –coverages)