Dave Denault & Brian Scarlett IICWG October 2005 Interoperable Data Formats in Production Systems.

Dave Denault & Brian ScarlettDave Denault & Brian ScarlettIICWG October 2005IICWG October 2005

Interoperable Data Interoperable Data Formats in Production Formats in Production

SystemsSystems


SystemsSystems

Presentation ContentPresentation Content

• Defining interoperability• The advantages of interoperability• Achieving interoperability;

• Interoperability with sameness• Interoperability with interfaces

• The need for standards• Functional requirements;

• Core interchange technologies• Open Web mapping standards (WMS)

Defining InteroperabilityDefining Interoperability

• The International Organization for Standardization (ISO) defines interoperability as;

“The ability to communicate, transfer and process data among functional units in a manner that requires the user to have little or

no knowledge of the unique characteristics of these units.”

Defining InteroperabilityDefining Interoperability

•But we will use the less formal definition of;

“Enable the largest possible audience to access and

integrate the data with the least amount of effort and

time.”

Reasons for InteroperabilityReasons for Interoperability

• To simplify the dissemination of data and services to partners and clients.

• To facilitate improved data usability in addition to basic accessibility.

• To promote collaboration both within and external to the organization by;• Accelerating the research process• Encouraging knowledge discovery• Keeping the way clear for “future

questions and approaches”

Reasons for InteroperabilityReasons for Interoperability

• Get the data out there and make it simple to locate for everyone.

• Make the data as easy to work with as possible – minimize data handling.

• Document the data sufficiently such that others can work with the data in new and unanticipated ways.

In other words;

Interoperability via SamenessInteroperability via Sameness

• A simple solution is to have all data providers work within the same technical environment.

• This solution typically requires;• Use the same commercial software• Use the same applications• Use the same operating systems• Use the same database designs• Use the same internal data formats,

etc

Interoperability via SamenessInteroperability via Sameness

• Many organizations have demonstrated that “sameness” can be impractical…

• More time-consuming to implement.• Can be difficult to maintain over

time.• Slower to adapt as business

evolves.• Some business requirements are

unique and support by all data providers can become a burden.

Achieving InteroperabilityAchieving Interoperability

• An alternative solution is to support heterogeneous technical environments which communicate via “interfaces”.

• Interfaces determine what can pass in/out of an environment.

• What does this require?• Standards• Standards• And more standards

• These standards must be well-defined and complete and universal.

Interoperability and the WebInteroperability and the Web

• The World Wide Web (W3 or Web) is a good example of how standards can work.

• The Web is supported by the WWW Consortium (W3C) which has the mandate;• “To develop interoperable technologies to lead

the Web to its full potential.”

• Prior to 1994, incompatible HTML versions created problems when using Web pages.

• W3C promoted a set of core principles and components to be supported by everyone.

• W3C helped to create the current Web.

Interoperability for IICWGInteroperability for IICWG

• Basic functions required in an interoperable environment include

• #1: Core interchange technologies that define machine-readable and machine-interpretable data.

• #2: The deployment of interactive geospatial data using Internet accessible and open standards.


• #1: Core Interchange Format •Used between data providers.•Would also support external

partners such as researchers and modellers.

•With full metadata, the data is self-describing (e.g. MANICE attributes)

•Replaces the multiple exchange formats used now (e.g. coverages, shapefiles, ASCII files, etc)


• #2: Standards for Interactive Geospatial Data;•Used primarily for sharing data

with clients and the public.•Clients do not need to have

expensive software to use the data (Web browser is possible)

•Could also be used for sharing data with partners since most GIS software can consume these services too.

Core Interchange FormatCore Interchange Format

• Without a core interchange format, data conversions are often required.

• But reducing the amount of this manipulation is desirable since;

• Data conversion is costly to implement and maintain.

• Dataset-specific software is not always available to all users.

• Data quality can be compromised during conversion (losses, alterations, misinterpretations)

Interchange FormatsInterchange Formats

• SIGRID-3 is an example of an existing interchange format.

• SIGRID-3 is a specification for;• Vector data objects (polygons)• The attributes of data objects• Metadata for the objects

• Other emerging standards include the Geographic Markup Language (GML)

• GML uses XML to express geospatial vector features and their attributes.

Interchange Formats (NAIS)Interchange Formats (NAIS)

• Although intended for archival purposes, SIGRID-3 is being considered as the interchange format for NAIS.

• Some extensions to the SIGRID-3 specification are being proposed to fulfill this role within NAIS.

Canadian Ice ServiceInternal system

(e.g. ISIS)

Canadian Ice ServiceInternal system

(e.g. ISIS)

InterchangeFormat

(e.g. SIGRID-3)

InterchangeFormat

(e.g. SIGRID-3)National Ice Center

Internal system(e.g. SIPAS)

National Ice CenterInternal system

(e.g. SIPAS)

Interactive Geospatial DataInteractive Geospatial Data

• Standards already exist to provide simplified access to distributed geospatial datasets.

• These standards are actively supported by the Open Geospatial Consortium (OGC)

• 280+ commercial, government and research organizations are involved.

• The OGC encourages development of standards for geospatial content and processing and exchange.

OGC Web Map Service (WMS)OGC Web Map Service (WMS)

• Compliance with OGC standards enables users to exchange and apply information directly across;• Different platforms (e.g. UNIX,

Microsoft Windows, Linux, Mac OSX)• Different applications

• A key aspect of the OGC standards is that they are “open standards”.

• Open = non-proprietary with free distribution (i.e. no royalties or fees)


• The Web Map Service (WMS) uses HTTP, the basic protocol of the of the Web, to issue requests.

• The response is a conventional pictorial format such as JPEG or PNG, allowing standard Web Browsers to function as client applications.

• Most commercial GIS software and many free applications/toolkits also support WMS (or intend to)


• Currently supporting WMS; • ESRI ArcGIS Desktop (e.g. ArcView,

ArcInfo, ArcExplorer, ArcGlobe)• ESRI ArcGIS Server-side (e.g. ArcIMS)• Autodesk MapGuide• Intergraph GeoMedia WebMap• The GeoServer Project• IONIC Red Spider Web• Mapinfo MapXtreme• Oracle MapViewer 10g• Refractions uDig viewer

(GeoInnovations)

As of October 2005:

61 products fully compliant

240+ products being tested


Web Servercompliant with

OGC WMS


OGC WMSGeospatialData

Stores(e.g. Geodatabase,

Shapefiles, …)

Data Provider:Internal GIS systems

(e.g. SIPAS, ISIS)

Data Provider:Internal GIS systems

(e.g. SIPAS, ISIS)

Client/Partner/PublicWeb Browser

(e.g. Firefox, IE,)

Client/Partner/PublicWeb Browser

(e.g. Firefox, IE,)

No plug-ins

required

External GIS systems(e.g. ArcGIS) and

Viewers (e.g. uDig)

External GIS systems(e.g. ArcGIS) and

Viewers (e.g. uDig)

Local layers+

WMS layers


GeoSpatial Data

Web Server (WMS)

Web Server (WMS)

Client or Partner or

Public

Client or Partner or

Public

Geospatial Data

Web Server (WMS)

Web Server (WMS)

Geospatial Data

Web Server (WMS)

Web Server (WMS)

Access to Geospatial Data

Indirect Access to Geospatial Data

Combination Access to

Geospatial Data

SummarySummary

• Interoperability encourages the distribution and access of data with a minimal amount of user effort.

• The basis for interoperability is standards, as shown by the Web.

• Interchange formats would support system-to-system flows of data.

• Web mapping standards (e.g. OGC WMS) would support system-to-user flows of data.

Thank youThank you


SystemsSystems


SystemsSystems

www.opengeospatial.org

www.esri.com/software/standards

www.refractions.net

Interoperability PresentationInteroperability Presentation


OGC WMSThe GeoServer

Project


OGC WMSThe GeoServer

Project

External GIS ViewerRefractions uDig

External GIS ViewerRefractions uDig

External GIS systemsESRI ArcGIS 9.1

External GIS systemsESRI ArcGIS 9.1

SIGRID-3Shapefiles

From Canadian Ice

Service

SIGRID-3Shapefiles

From Canadian Ice

Service

Local Data:Shapefiles CoveragesImagery

Local Data:Shapefiles CoveragesImagery

External WebServer

compliant withOGC WMS

External WebServer

compliant withOGC WMS

Dave Denault & Brian Scarlett IICWG October 2005 Interoperable Data Formats in Production Systems.

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