OGC Reference Model Open Standards for Geospatial Interoperability Adapted from a Presentation by:...

OGC Reference ModelOpen Standards for

Geospatial Interoperability

Adapted from a Presentation by:

George PercivallOGC Chief Architect

Executive Director, Interoperability [email protected]

mailto:[email protected]

Helping the World to CommunicateGeographically

OGC Reference Model (ORM) Click on “Standards” at www.opengeospatial.org

• What is the purpose of the ORM?– Overview of OGC Standards Baseline– Insight into the current state of the work of the OGC– Basis for coordination and understanding of the OGC documents– Resource for defining architectures for specific applications

• Why Read This Document?– Better understand the OGC Standards Baseline– Better understand the ongoing work of the OGC– Gain an understanding necessary to contribute to OGC process– Aid in implementing one or more of the OpenGIS Standards

Copyright © 2009, Open Geospatial Consortium, Inc.

http://www.opengeospatial.org/


OGC Reference Model (ORM)

Organized in the following sections:

1. The Enterprise View of OGC

2. Geospatial Information

3. Geospatial Services

4. Reusable Patterns for Deployment

5. Implementations of OGC Standards

Structured along the lines of the ISO Reference Model for Open Distributed Processing

ORM Viewpoint 2:

The Enterprise View of OGC

1.1 Interoperability Is Essential

1.2 An Example: Web Map Service (WMS)

1.3 Business Processes Benefit from Geospatial Standards

1.4 The OGC Members and Programs

1.5 The OGC Standards and Specifications


What do we mean by interoperability?

"capability to communicate, execute programs, or

transfer data among various functional units in a manner

that requires the user to have little or no knowledge

of the unique characteristics of those units“

Source: OGC Abstract Specification Topic 12: Services. Derived from ISO 2382-1.


• Organizational

• Cultural• Legal • Technical


Interoperability allows a Common Reality

“What we are doing is facilitating a common picture of reality for different organizations which have different views of the reality, the disaster, the catastrophe, that they all have to deal with collectively”

David SchellCEO and ChairmanOGC



Copyright © 2008, Open Geospatial Consortium, Inc., All Rights Reserved.

Interoperability – You know when you don’t have it…

• Custom Integration

• High system lifecycle costs

• Difficult to rapidly mobilize new capabilities

• Duplication of effort, missed opportunities to collaborate


Multipleoverlaid

maps

One GetMaprequest:

Web Map Service (WMS) can get multiple maps

BordersElevation

cloud cover

Cities


Why Open Standards?

• Rapidly mobilize new capabilities – plug and play

• Lower systems costs

• Encourage market competition–Choose based on functionality desired–Avoid “lock in” to a proprietary architecture

• The decision to share information and services enabled by policy



Return on Investment

Multiple studies confirm the value and advantage of open standards based solutions:

– NASA Geospatial Interoperability: Return on Investment Study: http://gio.gsfc.nasa.gov/docs/ROI%20Study.pdf

– Value of Standards, Delphi Report: http://www.delphigroup.com/research/whitepapers/20030728-standards.pdf

– Economic Benefits of Standardization, DIN German Institute for Standardization: http://www.sis.se/upload/632248898159687500.pdf



What is the OGC?


• Open Geospatial Consortium, Inc. (OGC) – Not-for-profit, international voluntary consensus standards

organization– Founded in 1994, Incorporated in US, UK, Australia– 385 industry, government, research and university members

OGC MissionTo lead in the development, promotion and

harmonization of open geospatial standards …


Where does OGC fit in the ‘standards’ world?


OASIS/IETF / W3CInfrastructure: WSDL, UDDI, SOAP, XML

ISODomains: Object / Abstract Models, Content, Vocabulary

OGCSoftware Interfaces: Instantiate Domain and Dejure into Infrastructure

De

Fact

oD

e Ju

re

Domain Infrastructure


Alliance Partnerships

• International Organization for Standards (ISO)• World Wide Web Consortium (W3C)• Digital Geospatial Information Working Group (DGIWG) • OASIS• Open Mobile Alliance (OMA)• Internet Engineering Task Force (IETF)• buildingSMART International / Alliance (bSi / bSa) • IEEE Technical Committee 9 (Sensor Web)• Web3D Consortium• Many others


OGC Implementation in the Marketplace

• We know of several hundred products implementing OpenGIS Specifications

–See OGC “Registered Products” List under “Resources” at www.opengeospatial.org

• Formal Compliance certification is increasing in importance

http://www.opengeospatial.org/resources/?page=products

http://www.opengeospatial.org/

ORM Viewpoint 2: Geospatial Information

2.1 Geospatial Information Is Fundamental or “Everything is somewhere”

2.2 Information Specifications Architecture

2.3 Spatial Referencing

2.4 Maps and KML

2.5 Geographic Features

2.6 Geometry and Topology

2.7 Geography Markup Language

2.8 Sensor Web Enablement Information Standards

2.9 GeoDRM and GeoXACML

2.10 Metadata

2.11 OGC Schema Repositories


Every human activity happens somewhere – and “somewhen”!

• Can anyone in the audience think of any human activity that is not impacted by location or impacts a location?

• Geospatial Information Is Fundamental


Source: www.fao.org/docrep/008/ae929e/ae929e03.htm

http://www.fao.org/docrep/008/ae929e/ae929e03.htm


ORM Information Viewpoint

• Concerned with the semantics of information and information processing

• Geospatial Information Is Fundamental • Spatial Referencing• Maps and Features • Geometry and Topology• Geography Markup Language• Sensor Web Enablement Information• Policy and Rights Management • Metadata

Information Viewpoint

Helping the World to CommunicateGeographicallyInformation Viewpoint

Spatial Referencing

• Terminology with spatial reference, two cases:– Civic locations using geographic terms

• Examples: postal code, place name• Can be ambiguous / amorphous, e.g. Springfield, Danube River • ISO 19112 Spatial Referencing By Geographic Identifiers; and OGC

Gazetteer, Geocoder, Geoparser– Coordinate Reference Systems

• Consists of a coordinate system and a datum • OGC Abstract Specification Topic 2: Spatial Referencing By Coordinates

(basis for revision of ISO 19111:2003)

• Coordinate Transformations– Conversion: operation on coordinates that does not change datum, – Transformation: operation on coordinates that changes datum – OGC Abstract Specification Topic 2


Maps are display of spatial information

Image

Features

Data Source

Display Elements

Display

Render

Display Element

Generator

Filter

Device Characteristics

Image Constraints

Style

Query Constraints


Geographic features

• feature: an abstraction of a real world phenomenon

• geographic feature is a feature associated with a location relative to the Earth


Helping the World to CommunicateGeographicallyInformation Viewpoint

Geometry and topology conceptual schemas

• Geometry objects – Combination of a coordinate geometry and a coordinate reference

system – OGC AS Topic 1 - Feature Geometry, identical with ISO 19107

• Topology– OGC AS Topic 1 - Feature Geometry, identical with ISO 19107

• Query Operators – Characterizing topological relations between different features. – OGC AS Topic 1 - Feature Geometry, identical with ISO 19107

• Temporal– References to ISO 19108 — Temporal, ISO 8601

• Spatiotemporal Schema– Spatiotemporal conceptual schema under development in ISO TC211


Coverages

“A coverage is a feature that associates positions within a bounded space to feature attribute values”

• That is to say -- a collection of features that share a common regular geometry

• Examples

– Raster image

– Polygon overlay

– Digital elevation matrix

Latitude -->

Longitude -->

Value

= 80

Value

= 95

Value

= 10

0 Value

= 85

Value

= 50

Value

= 30

Value

= 55

Value

= 90

Value

= 85


OpenGIS Geography Markup Language (GML)

• GML is application of the eXtensible Markup Language (XML)– Based on XML specified by World Wide Web Consortium (W3C)– Specifies XML Schemas that specify XML encoding of geographic

features, their geometry, and their attributes

• GML encodes digital feature data– Encodes features, attributes, geometries, collections, etc.– Applications require specifying more specific Application XML

Schemas– GML v3, supports 2 1/2 and 3D geometry as well as complex

geometry and topology

• GML 3 is also ISO 19136


Another Information Community’s Schema

Highway is:_Pavement thickness_Right of way_Width ….

Cell transm. Platform is:_Location_No. of antennas_Elevation ….

One Information Community’s Schema

Road is:_Width_Lanes_Pavement type ….

Cell tower is:_Owner_Height_Licensees ….

(an instance of Road in one IC’s schema)

Mayberry’s Cell Tower

(an instance of Cell Transm. Platform in another IC’s schema)

Mayberry Road

Support for complex geometries, spatial and temporal reference systems, topology, units of measure, metadata, feature and coverage visualization.

GML defines a data encoding in XML that allows geographic data and its attributes to be moved between disparate systems with ease

GML: Representing Geographic Features


GML Application Activities

Profiles – GML Point Profile– GML Simple Features Profile– GML GeoShape for use in IETF– GML in JPEG2000– GeoRSS: GML Serialization

US NSDI GML Schemas for Framework Datasets– Base Transportation– Roads– Governmental Units– Linear Reference Systems– Dictionaries– Hydrology

Community Application Schemas– Climate Science Modeling Language

(CSML)– CityGML – CleanSeaNet– NcML/GML (NetCDF and GML)– TDWG Biodiversity GML– GeoSciML - Geological Sciences ML– MarineXML – Ground Water Modeling Language– WaterML

Further information on OGC Network

http://www.ogcnetwork.net/node/210

30

http://www.ogcnetwork.net/node/210


OGC Sensor Web Enablement

• Sensors connected to and discoverable on the Web• Sensors have position & generate observations• Sensor descriptions available • Services to task and access sensors• Local, regional, national scalability• Enabling the Enterprise

31

Webcam

EnvironmentalMonitor

IndustrialProcess

Monitor

StoredSensor

Data

TrafficMonitoring

Satellite-borneImaging Device

Airborne Imaging Device

HealthMonitor

StrainGauge

TempSensor

AutomobileAs Sensor Probe


Observations

• An observation feature binds a result to a feature of interest, upon which the observation was made

• Observation - act of observing a property or phenomenon, with the goal of producing an estimate of the value of the property.

• Observations are modeled as Features within the context of the General Feature Model [ISO 19101, ISO 19109].



Copyright 2006, OGC 33

SWE Languages and Encodings

GML Observations Application

Schema

TransducerML

Observations & Measurements

(O&M)

Information Model for Observations and Sensing

Sensor and Processing Description

Language

Multiplexed, Real Time Streaming Protocol

SWE Common Data Structure And

Encodings

SensorML



Metadata

• Metadata is data about data• Dataset metadata

– characterize geographic data; enables in most efficient manner; facilitates data discovery, retrieval and reuse; fitness for of use

– datasets, aggregations of datasets, individual geographic features,– core metadata - subset of the full set of elements– OGC adopted ISO 19115, additional material in 01-111

• Service Metadata– "Get Capabilities" operation common to all OWS1 services, returns a

"capabilities document" describing the service. – OGC AS Topic 12 (identical with ISO 19119)

• Registry Information Model (RIM)– all metadata and data types are registry objects. – RIM under development in OWS


Geospatial Rights Management

• Digital rights management for geospatial (GeoDRM) builds on larger market by with geospatial resources specifics

ORM Viewpoint 3:

Geospatial Services

3.1 Services Architecture

3.2 OGC Web Services

3.3 Sensor Web Enablement (SWE) Services

3.4 Processing Services and Service Chaining

3.5 Mass Market Services

3.6 Open Location Services

3.7 Fine-Grained Services


Computational Viewpoint

Services, Interfaces and Operations

• Service - distinct part of the functionality that is provided by an entity through interfaces,

• Interface - named set of operations that characterize the behavior of an entity

• Operation - transformation or query that an object may be called to execute. Each operation has a name and a list of parameters.

• Variations:– Granularity: coarse-grained vs. fine-grained– Data/service coupling: tight vs. loose

• See OGC Abstract Specification Topic 12 - OpenGIS Service Architecture (ISO 19119)


OGC Web Services (OWS)


Web Map Service (WMS)

Web Feature Service (WFS)

Web Coverage Service (WCS)

Catalogue (CSW)

Geography Markup Language (GML)

OGC KML

Others…

Just as http:// is the dial tone of the World Wide Web, and html / xml are the standard encodings, the geospatial web is enabled by OGC standards:

Relevant to geospatial information applications: Critical Infrastructure, Emergency Management, Weather, Climate, Homeland Security, Defense & Intelligence, Oceans Science, others

Web MapServer

Web CoverageServer

Web FeatureServer


Copyright (c) 2009, Open Geospatial Consortium, Inc. 40

Multiplethematic

data layers

GetFeaturerequest:

Web Feature Service (WFS) gets operable feature data from multiple servers

Cities

BordersElevation

Each layer is data, not merely a view:

Country is:_ Name: Italy_ Population: 57,500,000_ Area: 301,325 sq km. . .


Architecture using WMS, WFS, and SLD

Web Browser

WMS Client

Web Feature Server

SLD Doc

Web Map Server

GetMap

Map Features

GetFeature

FetchReference XML


Section 3.3: Sensor Web Enablement (SWE) Services


Sensor Model Language (SensorML)Transducer Markup Language (TML)Observations & Measurements (O&M)Sensor Planning Service (SPS)Sensor Observation Service (SOS)• Sensor Alert Service (SAS)• Web Notification Service (WNS) IEEE (sensor) and OASIS (alert) stds

Enables discovery, access and application of real time sensor observations for enhanced situational awareness


Copyright 2006, OGC 45

CatalogService

SOS

SAS

SPS

Clients

SWE Components – Web ServicesAccess Sensor Description and

DataCommand and Task Sensor

Systems

Dispatch Sensor Alerts to

registered Users

Mike Botts, Alexandre Robin, Tony Cook - 2005

Discover Services, Sensors, Providers,

Data

Accessible from various types of clients from PDAs and Cell

Phones to high end Workstations

Processing Services, Workflow and Service Chaining


OGC Web Processing Service (WPS)

© 2009 Open Geospatial Consortium, Inc.

WPSGetCapabilities ExecuteDescribeProcess

Algorithms Repository

…

…

Algorithm 1

Data Handler Repository

…

…

Data Handler A

Communication over the web using HTTP

WPS-client

Web Processing Service


“Chaining” Web Services For Decision Support

48

…

WCS (NASA Data Pool)

WPS - Classification(Producer-C,Vendor-3)

WPS - WCTS (Producer-B, Vendor-2)

WFS (Producer-n, Vendor-x)

Internet

Web Servers

OGC Interfaces

Service chaining creates Value-added products Decision Support

Client

Geoprocessing Worklow developed in OGC Testbeds since 2004

Assess Wildfire Activity


49

Mass Market Geo

• OGC Vision is being realized in ‘mass market geo’– Google Earth & Maps– Windows Virtual Earth– Yahoo Maps– Mobile phone location based services (e.g. Nokia Ovi)– Real time ‘sensor connection’ to the world coming soon

• Standards for Mass Market Geo need to match weight of uses– Lightweight application schemas of encodings– GeoRSS– GeoJSON– Open Location Services


Open Location Services (OpenLS)

• OpenLS An open (middleware) platform for location-based application services

for mobile assets and terminals. The primary goal of the OpenLS initiative series is to define the

specifications for the “Core Services and Abstract Data Types (ADT)” that comprise this platform.

• XML for Location Services - Core Spec Package, V 1.0– Interfaces for core LS functions: geocode, reverse geocode, directory,

gateway, etc.• OpenLS Pending Documents

– OpenLS Presentation Experiment– OpenLS Location Refinement Service– OpenLS Positioning Service– OpenLS Navigation Service

ORM Viewpoint 4: Reusable Patterns for

Deployment


ORM Viewpoint 4: Reusable Patterns for Deployment

• OGC technology applied in several environments– Reusable patterns use OGC standards to accomplish typical tasks.

• Engineering patterns– Publish, Find and Bind Pattern– Geospatial Portal and Clients– Multi-Tier Architectures– Spatial Data Infrastructures– Sensor Webs– Workflow and Service Chaining


Bind

Find Publish

Broker

Client Service

Registry

Publish-Find-and-Bind Pattern

– Resource providers can advertise their resources (publish)– End users can discover resources that they need at run-time (find)– End users and their applications can access and exercise resources

at run-time (bind)


Service tiers in OWS architecture


Reference Architecture Service Distribution

InternetPortrayalServices

PortrayalServices

PortrayalServices

Maps Styling Coverages Map Context

DataServices

DataServices

DataServices

Features Gazetteer Coverages Symbology Mgmt

CatalogServicesCatalog

ServicesCatalog

Services

Data Discovery Service Discovery Catalog Update Query Languages

PortalServices

Viewer Clients Discovery Clients Management Clients Access Control Exposed Services

Geospatial Portal


GEOSSClearinghouses

GEO Web Portals

GEOSS Common Infrastructure

Components & Services

Standards andInteroperability

Best PracticesWiki

User Requirements

Registries

Main GEOWeb Site

CSW WMS

CSW

Registered Community Resources

Community Portals

Client Applications

Client Tier

Business Process Tier

CommunityCatalogues

AlertServers

WorkflowManagement

ProcessingServers

Access Tier

GEONETCastProduct Access

ServersSensor Web

ServersModel Access

Servers

Test Facility

MediationServers

CSW WMS

CSW W*S

WMS

WFS WFS SOS SAS SPS W*S

CSW

WPS

GEOSS Engineering Viewpoint

ORM Viewpoint 5:

Implementations of OGC Standards

5.1 OGC Compliance Test Program

5.2 Registered Implementations

5.3 Operational Networks using OGC Standards


ORM Viewpoint 5:

Implementations of OGC Standards

• OGC Compliance Test Program• Registered Implementations• Operational Networks using OGC Standards



Market Availabilitysee http://www.opengeospatial.org/resource/products

• Free availability of standards stimulates market

• Hundreds of Products Implementing OGC Standards

• Compliance Test & Certification Program

http://www.opengeospatial.org/resource/products


From portal select desired theme(s) and area of interest

Wizard picks appropriate workflow for desired result

Wizard

Mozambique

Disaster Management Information System (DMIS)

Workflows

Estimated rainfall accumulation and flood prediction model

Flood Model

Selected workflow automatically activates needed assets and models

Baseline water level, flood waters and predicted flooding

GEOSS AIP-2 Flood Prediction and ResponseLed by NASA, Spot Image, Northrop Grumman, ERDAS


Geoparser

GSDI - A Global Capability Based on Commonly Accepted Best Practices

• Reduced deployment and operational costs

• Support public and private decision making requirements

• Establish partnerships to share successes, capture and share best practices

• Easier access to multiple online info sources and services

• Minimize duplication through reuse of geospatial information and technology solutions within an across organizations

ClearinghouseClearinghouseGeoparser

VendorData

Local Government

NationalGovernment

OtherCollections

Clearinghouse

WhovilleCedar Lake

WhovilleCedar Lake

BuildingsRoadsImagesTargetsBoundaries ...

CatalogView

Common interfaces enable interoperability

Queries extract info from diverse sources

Integrated View

Gazetteer CoordinateTransform

Web Mapping Server, Web Feature Server, Web Coverage Server Catalog Services

OtherServices

Metadata

DataMetadata

DataMetadata

DataMetadata

Internet

Geoparser

Geocoder


Parting Thoughts…

• OGC Reference Model is moving into an annual revision cycle.• Let’s consider including some real world practical examples of

Semantics and Ontology work as direct reference in OGC Reference Model:– One Geology www.onegeology.org– Marine Semantic Mediation Web Services (MMI)– Semantic Sensor Web

• Semantic Sensor Network• Hydrologic Sensor Web

• OGC deeply engaged implementation level standards development– Identify and socialize S/O topics in the OGC process to spur

development, prototyping and testing

http://www.onegeology.org/



Interoperability is about Organizations

“Interoperability seems to be about the integration of information. What it’s really about is the coordination of organizational behavior.”

David SchellCEO and ChairmanOGC

OGC Reference Model Open Standards for Geospatial Interoperability Adapted from a Presentation by:...

Documents

Transcript of OGC Reference Model Open Standards for Geospatial Interoperability Adapted from a Presentation by:...