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What is infrastructure?
"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)
- •Platform independent
- •Usually used over HTTP
SOAP Basic Structure
- SOAP Message
- Envelope [required]
- 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
- – Performance
- – Scalability
- – Robustness
- – Maintainability
- – Costs
- • 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
- • Virtualization
- • Ubiquity
- • Elasticity
- • Scalability
- • Reliability, SLA
- • Pay-per-use
- • On-demand
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
- •Engineering Report
- •Discussion paper
- •White paper
- •Best practice document
- •Abstract specification
- •Implementation Standard
OGC Web Services Architecture
- •Defined on Internet standards: URLs, HTTP, XML
- •SOA based:
- •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
- –Geospatial service
- –Imagery–Information communities
- –Information management
- –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)
- –Different bindings
- •New version 2.0.0
- –Former version 1.1.0