OGC Newsletter - December 2001
The View From Here
News From the Vancouver Meeting
OGC Review Board Proposed
New Contracts and Implementations
Implementations of OGC Specifications
Open Web Services Interoperability Program Reports: Overview
OGC In The News
Back issues of OGC News are available.
THE VIEW FROM HERE
As we wrap up 2001, and the twelfth issue of OGC News, we are gratified at the continued interest in geospatial interoperability. The need for, and benefits of this important work are filtering out to all corners of the GIS and IT communities. A recent webcast hosted by OGC, FGDC and GITA included virtual attendees from the city of Tallahassee, the city of Newport News, as well as private companies including Utility Partners, Sprint, and Delorme. We look forward to growing the variety and the number of active participants moving toward a vision of seamless data and service sharing in the year ahead.
Editor, OGC News
adena [at] opengeospatial [dot] org
Critical Infrastructure and Collaborating Communities
Nationally and internationally, issues of homeland security, national and global defense, and emergency management have moved to center stage. Areas of concern that have fallen under the term "sustainable development," too, are taking a higher profile as policy makers consider long term solutions. Many more people than before understand how "Critical Infrastructure" resource networks are vital to our well-being, our livelihoods and our environment at the local, national, regional and global levels. The scope of this vision is broadening from protecting nearby water supply and transportation systems to include concern about resource networks in developing countries.
This broad-based attention to Critical Infrastructure will have consequences for OGC. Worldwide, the management of Critical Infrastructure depends on tools to access, combine and fuse complex spatial data streams into intelligible information for decision-making. More people than ever before are becoming aware of the delays and costs of non-interoperability when trying to share and use spatial data from diverse sources. OGC stands at the gate. We as a consortium will be increasingly engaged with organizations seeking better collaboration within and across communities of diverse disciplines and location.
We are very fortunate to have Columbia University's Columbia Earth Institute (CEI) hosting our February meetings at Columbia's Lamont-Doherty Earth Observatory campus. The New York venue is appropriate because of New York City's role in a new OGC Web Services initiative. But it is also the case that CEI is a major center for linking new understandings of Earth, derived from the physical sciences, to research on natural ecological and human systems and also to the policy process. OGC's promotion of interoperability focuses increasingly on collaborating communities and institutional interactions. Because CEI is an important catalyst for collaboration and change in the US and international research communities, CEI's participation in OGC makes sense for both organizations, with benefits ultimately accruing to a very broad set of stakeholders.
OGC programs related to Critical Infrastructure issues will be highlighted during our week of meetings in February. As one would expect, there will be important presentations about Open Location Services, OGC Network, and the New York City OWS initiative. But also, in attendance will be representatives from CEI, USAID , Europe's JRC, the US Critical Infrastructure Protection Initiative, Geospatial One Stop (E-Government) and the United Nations. Significant OGC programs involving some of these organizations will be announced. Watch our website for the meeting agenda, which will be posted in January. As always, we invite you to attend.
I wish you all a happy holiday season and a very good new year.
President, Open GIS Consortium
NEWS FROM THE VANCOUVER MEETING
During the OGC Technical Committee meetings in Vancouver the week of December 2, the Technical Committee approved the adoption of the Web Feature Server proposal in conjunction with the Filter Proposal, as OGC adopted Implementation Specifications.
The Web Feature Server Interface Specification (WFS) describes data manipulation operations on OpenGIS® Simple Features (e.g., points, lines, polygons) so that servers and clients can "communicate" at the feature level. Therefore, a WFS request - like those supported in many GIS and RDBMS packages - consists of a description of the query and data transformation operations that are to be applied to WFS enabled spatial data warehouses on the Web. The request is generated on the client and is posted to a WFS server. The WFS Server "reads" and executes the request, returning the result in a feature set as Geography Markup Language (GML). A GML enabled client then can use the feature set.
In contrast to the OGC Web Map Server implementation, which delivers a picture, a WFS implementation in client software supports the dynamic exploitation and access of feature (vector) data and associated attributes. This capability opens the door to enhanced spatial analysis, modeling and other operations based on the intelligence of the attributed data. There is an additional set of interfaces, beyond feature access, in the WFS for supporting simple transactions including: Create a Feature, Delete a feature, and Update a feature.
OGC Interoperability Program (IP) activities drove the contents and capabilities of WFS. The user requirements, use cases, and interface development were the result of work in a variety of testbeds and pilots, including the Geospatial Fusion Service Testbed, Web Mapping testbeds, and the current OGC Web services testbed. IP allows for the rapid specification, design, development, and testing of potential OGC interfaces.
Executive Director, OGC
OGC REVIEW BOARD PROPOSED
There has been tremendous growth in specification development activity due to the combined actions of the Interoperability Program (IP) and the Specification Program (SP). With this growth comes increased risk of interface, vocabulary, and architecture inconsistency and divergence. Currently, there is no forum or procedure for appeals or concerns regarding process or technical issues.
OGC staff, therefore, has proposed the creation of a Review Board. This Board will:
Create and maintain documentation of procedural baselines (policies and procedures) and technical baselines (requirements and architecture).
Consider member appeals about the process and make process change recommendations, if necessary, to the appropriate body.
Consider member appeals about technical issues and make recommendations, if necessary, to the appropriate body.
Review RFP, RFC, RFT, and RFQ documents, as they are under development and before they are issued, for consistency with procedural and technical baselines (requirements and architecture) and make change recommendations to the appropriate body.
Review other Work Items (in the OGC Roadmap sense), as they are created, for consistency with procedural and technical baselines (requirements and architecture) and make change recommendations to the appropriate body.
The Review Board will not dictate new or revised process, procedure, or technical approaches. It will provide guidance and recommendations to the Technical Committee, Planning Committee, or OGC Board of Directors as appropriate. The proposed chair, Kurt Buehler, CTO, will work with committee members Cliff Kottman, Jeff Harrison, Carl Reed, and Sam Bacharach.
The OGC staff will provide the final plan to the OGC Board of Directors along with the required Bylaws changes for the creation of the Review Board. Assuming Board approval, the appeals process will be designed and examined by the OGC membership. Finally, work will begin to gather existing procedural and technical baselines for member consideration.
Vice President, Chief Technology Officer, OGC
The technical committee approved the adoption of the Web Feature Server proposal in conjunction with the Filter Proposal as OGC adopted Implementation Specifications at the Vancouver meeting this month.
The specification is still being finalized with comments made during the review period. It will be available for public download in the coming weeks.
OpenGIS® Implementation Specifications
NEW CONTRACTS AND IMPLEMENTATIONS
CARIS (www.caris.com) along with Management Group Ltd. (www.holonics.ca), and Nautical Data International (www.ndi.nf.ca) received a contract to provide a standards-based set of geospatial web services for the Department of Fisheries and Oceans Canada (DFO). CARIS Spatial Fusion, specifically the OGC Cascading Web Mapping Server and the OGC Web Feature Server will be part of the solution. Backend Spatial Fusion Services such as the OGC Cascading Web Mapping Server will enable DFO to incorporate layers from various proprietary data formats in multiple spatial reference systems. The OGC Web Feature Server will allow database transactions such as insert or select to be conducted over the web for spatial objects. Completion of the GeoPortal Project is set for March 2002.
Snowflake Software has introduced a free GML viewer. Designed to support the new Ordnance Survey MasterMap, the viewer supports both topology & independent polygon GML formats.
IMPLEMENTATIONS OF OGC SPECIFICATIONS
SRI has implemented OGC's Web Map Server 1.1.0 specification in its TerraVision client and server products.
IONIC Software has implemented WMS 1.1.0 and the Web Feature Server specification in a variety of client and server products including the company's General Application Framework and Suite for ORACLE.
Implementations of OGC Specifications
If you have any questions, concerns, or suggestions or if you wish to add your OGC based products to OGC's implementations listing please contact Mark Buehler, mbuehler [at] opengeospatial [dot] org.
The OGC Interoperability Program (IP) is a global, collaborative, hands-on engineering and testing program designed to deliver proven candidate specifications into OGC's Specification Development Program.
As you read through our progress report this month, you will notice that we have categorized our initiatives under "Plug and Play Infrastructure Development" and "Collaborating Communities" headings. This organization has come about as a result of our work to maximize success and efficiency by integrating initiatives as much as possible. Over the next few months, we will also be reporting on several interoperability planning initiatives that will fall under the heading of Enterprise/Domain Architecture.
Plug and Play Infrastructure Development: This category of IP initiatives focuses on the development of new specifications to meet the requirements expressed by OGC members.
- OGC Web Services Initiative Thread Set 1 (OWS-1)
OWS-1 is on schedule, with engineering specification documentation due later this month. Nine Interoperability Program Reports (IPR's) are exptected: Service Model IPR, Registry Service IPR Web Coverage Service IPR, Web Feature Service IPR, Web Map Service IPR Coverage Portrayal Service IPR, Sensor Model Language IPR, Sensor Collection Service IPR, and Style Layer Descriptor IPR.
For a detailed look at the current status of OWS Interoperability Reports (IPRs) and Draft IPRs (DIPRs) see the online version of OGC News at http://www.opengeospatial.org/press/newsletter/index.htm
- Open Location Services Phase 1 (OpenLS-1)
OpenLS-1 is proceeding on schedule for demonstrations in February and March 2002. A day and a half work session was held at Vancouver after the Technical Committee meeting had ended. Specifications were finalized during the week of 17-21 December via teleconferences held by the Working Group.
Collaborating Communities: IP initiatives are often designed to help users exercise and validate the use of interoperable solutions in the context of their operations, which typically involve a range of interactions with physically separate and distributed organizations. IP has grouped pilot initiatives under the Collaborating Communities category to emphasize this point, and to allow opportunity for achieving economies of scale in cost and scheduling by identifying and consolidating common requirements between initiatives wherever possible. Initiatives under collaborating communities includes the Multi-Hazard Mapping Initiative, Military Pilot Project, and several other planned initiatives, which we will report on next month.
- Multi-Hazard Mapping Initiative Phase 1 (MMI-1)
The kickoff for MMI-1 was held at the BAE facilities in Reston Virginia on December 10 and 11, 2001. The Federal Emergency Management Agency (FEMA) has sponsored MMI-1 to develop a standards based framework for the discovery and distribution of multi-hazard mapping data between federal, state, and local emergency management agencies. This framework will be built around Open GIS standards using commercial off the shelf (COTS) software. Attending MMI participants include Compusult, CubeWerx, ESRI, HDM, Intergraph, IONIC, MapInfo, and SAIC.
- Military Pilot Project, Phase 1 (MPP-1)
The OGC Military Pilot Project, Phase 1 (MPP-1) continues to generate significant activity with multiple Interoperability Program Reports issued last month including reports on XML for Imagery and Map Annotation (XIMA), Styled Layer Descriptor (SLD) and Web Coverage Server (WCS). OGC is pleased to announce that IMC, a consortium of Mitsubishi, NEC and Hitachi business interests, has joined MPP-1 as Sponsor. OCG will be working with IMC and other MPP-1 Sponsors over the next few months to leverage the interoperable vendor solutions and engineering specifications generated by MPP-1 into greater geoprocessing interoperability potential for military users.
- Critical Infrastructure Protection Initiative (CIPI)
The OGC Government Special Interest Group recently recommended that IP begin planning an OGC Interoperability Initiative designed to test the application of interoperable technology to meet Critical Infrastructure detection, prevention, planning, response, and recovery challenges. The Critical Infrastructure Protection Initiative builds on the OGC interoperability developed over the past several years, and will apply emerging OGC Web Services and GeoFusion Services. CIPI consists of development and testing activities to be conducted in coordination with federal, state, local government, commercial, and non-government organization sponsors. Planning and conduct of the CIPI initiative will depend on an adequate level of sponsorship.
Organizations interested in sponsoring or participating in OGC Interoperability Program initiatives should contact Jeff Harrison at (703) 491-9543.
Director, OGC Interoperability Program
OPEN WEB SERVICES INTEROPERABILITY PROGRAM REPORTS: OVERVIEW
OGC Interoperability Reports (IPRs) are not OGC Standards or Specifications. IPRs, and Draft IPRs (DIPRs) present a discussion of technology issues considered in an Interoperability Initiative of the OGC Interoperability Program. The purpose of the IPR and DIPR is to create discussion in the geospatial information industry on its topic. DIPRs and IPRs do not represent the official position of the OGC nor of the OGC Technical Committee. IPRs and DIPRs are subject to change without notice and may not be referred to as an OGC Standard or Specification. However, the material found in IPRs and DIPRs are often intended to lead to the definition of OGC Implementation Specifications, per the OGC Technical Committee's Specification Process.
The remainder of this document lists and describes candidate IPR documents that are currently being considered or actively developed within the OWS-1 Interoperability Program.
Service Model IPR
The Service Model DIPR defines a general paradigm for geospatial service interactions and dependencies. The Service Model is a framework for describing services, their interfaces, and their operations in a standard way for purposes of publishing, discovery and invocation. This report defines a high-level OpenGIS Web Service Model, defines the different components that make the model, characterizes the use and behavior of those components, discusses through use-cases some of the component interactions, identifies those parts of the system that are necessary infrastructure and those that are optional, and defines profiles of the Service Model for specific technology platforms.
Critically important topics of the Service Model include:
a hierarchy of service types and their operations
mechanisms for registering information about web resource (service and data) types and instances for purposes of publishing, finding and accessing resources
service capabilities describing the service type, service provider, and
other descriptive metadata about the service
service operations using WSDL for HTTP GET, HTTP POST and SOAP bindings
the type and structure of the data/content on which a service operates
Registry Service IPR
The Registry Service DIPR defines a common mechanism to classify, register, describe, search, maintain and access information about OGC Web resources. OGC Web resources are network addressable instances of typed data or services. Types of registries are differentiated by their role such as registries for cataloging data types (e.g., geographic feature types), online data instances (e.g., datasets and repositories), service types (e.g., WFS, WCS, WMS, SCS) and online service instances (e.g., NASA's WCS, USACE's WMS, NIMA's WFS, EPA's SCS).
Registry services allow:
resource providers to publish descriptive information about resource types and instances
resource requestors to discover information about resource types and instances and
resource requestors to access resource providers.
The Registry Service Interface defines interfaces that allow the discovery, access and management of geospatial data and services based on the concept of interface operations passing Request-Response Message Pairs between a service requestor (client) and a service provider (server). Stated another way, the Registry Service Interface uses a messaging based structure to describe the access and invocation of Registry Services.
OWS-1 will also revise the Registry Service interface as required to support standard mechanisms, as defined in the Service Model IPR, for describing Registry instances, their operations and bindings.
Web Coverage Service IPR
The Web Coverage Service (WCS) allows access to geospatial "coverages" containing values or properties of geographic locations, rather than static maps (server-rendered as pictures). WCS deliver coverage data (e.g., images or DTED) in response to queries from HTTP clients. Access to intact (unrendered) geospatial information is needed for client-side rendering, multi-valued coverages, and input into scientific models and other clients beyond simple viewers. OWS-1 will test and revise the WCS interface to support delivery of images, multi-spectral imagery, elevation data (e.g., DTED) and other scientific data.
OWS-1 will also revise the WCS interface as required to support standard mechanisms, as defined in the Service Model IPR, for describing instances, their operations and bindings. Web Feature Service IPR
The Web Feature Service (WFS) supports INSERT, UPDATE, DELETE, QUERY and DISCOVERY of geographic features. WFS deliver GML (XML) representations of simple geospatial features in response to queries from HTTP clients. Clients (service requestors) access geographic feature data through an WFS by submitting a request for just those features that are needed for an application. The client generates a request posts it to a WFS instance (a WFS server on the Web). The WFS instance executes the request, returning the results to the client (service requester) as GML. A GML-enabled client can manipulate or operate on the returned features. WFS also supports simple transactions for INSERT, UPDATE and DELETE operations.
OWS-1 will revise the WFS interface as required to support standard mechanisms, as defined in the Service Model IPR, for describing instances, their operations and bindings.
Web Map Service IPR
The Web Map Service (WMS) enables maps in graphical form to be delivered in response to queries from HTTP clients. A "map" is a visual representation of geographic data; a map is not the data itself. These maps are generally rendered in a pictorial format such as PNG, GIF or JPEG, vector-based graphical elements in Scalable Vector Graphics (SVG) or Web Computer Graphics Metafile (WebCGM) formats.
The WMS specification standardizes the way in which clients request maps and the way that servers describe their data holdings. Clients request maps from a WMS instance in terms of named layers and provide parameters such as the size of the returned bitmap as well as the spatial reference system to be used in drawing the map. In this way, a client application can make requests to different WMS implementations and the results can be overlaid to form a rich layering of map information.
OWS-1 will revise the WMS interface as required to support standard mechanisms, as defined in the Service Model IPR, for describing instances, their operations and bindings.
Coverage Portrayal Service IPR
The Coverage Portrayal Service (CPS) IPR proposes a standard interface for producing visual pictures from coverage data. Typically coverage data are retrieved via a WCS instance. CPS facilitates wider use of coverage data by making views of coverages visible within thin-clients (e.g., Web browsers). To a service requestor, the CPS appears as a WMS instance, but with additional parameters to control the retrieval and/or rendering of coverage data. The CPS may require the client to specify the targeted WCS.
CPS may be used to support:
assignment of multi-spectral bands in an image to color channels in a picture,
creation of chloropleth maps from coverage data using client-specified color-bins
preset rendering mechanisms such as hill-shaded elevation
combining multi-spectral pixel values according to client-specified or server-defined formulas (e.g., Normalized Difference Vegetation Index).
For OWS-1, CPS will extend the WMS interface and the OGC Styled Layer Descriptor (SLD) language, currently written to render WFS features, to support rendering of WCS coverages.
Sensor Model Language IPR
The Sensor Model Language IPR proposes an architecture specification for OpenGIS Web-enabled Sensors and related Services. This report describes the high-level OpenGIS Sensor Model, Sensor Model Language, Observation Model and Sensor Web Service Model, as part of the OpenGIS Web Service Model. This IPR defines the different components that make the Sensor Model, characterizes the use and behavior of those components, discusses through use-cases some of the component interactions, and identifies those parts of the system that are necessary infrastructure and those that are optional.
Topics of the Sensor Model include specification of:
Sensor Model Language: the language for describing a sensor, its parameters, and other descriptive metadata that relates to exploiting it through Web services (the SML is described in further detail below).
Sensor Registries: mechanisms for registering information about sensor service types and instances for purposes of publishing, finding and accessing sensor services as resources on the Web
Sensor Collection Service: Web Service for collecting sensor observations and viewing them in different ways
Observation Model: representation of type, structure and units of measure of sensor observations
Physical quantity dictionary: a glossary or taxonomy of physical quantities (measured) and categories (observed). The dictionary provides the infrastructure and templates for communities to generate their own dictionaries or taxonomies for physical quantities that can simply be "plugged-in" to a sensor web system. Sensor Model Language
The Sensor Model Language IPR proposes an XML schema for describing the geometric, dynamic, and observational characteristics of sensor types and instances. Sensors are devices for the measurement of physical quantities. There are a great variety of sensor types from simple visual thermometers to complex electron microscopes and earth observing satellites.
The purpose of the sensor description is threefold:
to provide general information about the sensor in support of data discovery,
to support the processing and analysis of the sensor measurements, and
to support the geolocation of the measured data.
The proposed Sensor Model Language is a human-readable, XML-based language that can be easily parsed by a wide variety of existing tools. The current standard calls for keywords in the English language, although consideration for internationalization of keywords should be considered if deemed beneficial. One of the benefits of using UTF-8 encoding within XML is its improved support for internationalization.
Sensor Collection Service IPR
The Sensor Collection Service (SCS) IPR proposes a standard interface for clients (service requestors) to collect and access sensor observations and manipulate them in different ways. SCS instances are collection points on the Web for disparate types and instances of sensors.
SCS instances deliver sensor observation values (e.g., temperature, ppm, chemical type) in response to queries from HTTP clients. Access to sensor information is needed for analysis by service requestors (e.g., client-side visualization), input into scientific models and processing by other services.
Style Layer Descriptor IPR
The Style Layer Dscriptor (SLD) IPR specifies the format of a map-styling language for producing georeferenced maps with user-defined styling. This document addresses the need for geospatial consumers (either humans or machines) to control the visual portrayal of the data with which they work. The ability for a human or machine client to define the styling rules requires a styling language that the client and server can both understand. Defining this language, called the StyledLayerDescriptor (SLD), is the main focus of this paper, and it can be used to portray the output of Web Map Servers, Web Feature Servers and Web Coverage Servers. The SLD is defined using XML Schema.
A styled layer can be considered as a transparent sheet with features symbolized upon it. A map is made up of a number of these styled layers put together in a specified order. The styled layers are said to be "Z-ordered." Users can define complex, or simple, maps by adding or removing styled layers. A styled layer itself represents a particular combination of 'layer' and a 'style' in which that layer can be symbolized. Conceptually, the layer defines a stream of features and the style defines how those features are symbolized. This concept is underlined by the fact that there may be multiple styles in which a layer can be symbolized.
We see the global market self-organizing around the concept of location (including the wireless and mobile business) and demanding a geo-spatial interoperable technology, one that is secure and ready for e-business. IONIC is a recognized leader in interoperability, delivering standard-based commercial off the shelf software (COTS) to the market. IONIC's strategy has always been based on the vision of interoperable distributed components for geo-enabling applications. We contribute to this process as co-authors of major specifications (WMS, WFS, GML, Geocoding, ...) and by participating actively to the Interoperability Program. IONIC has also confirmed its leading position in this business by being first to deliver a Java COTS implementing OGC specification to major customers like the European Space Agency, United States Government, Norwegian Mapping Agency, major telecommunications companies and others.
IONIC strongly believes that participating in OGC's activities together with many companies, large and small, provides tremendous collective efforts, and helps "geo-enable" more and more businesses. This is the power of a consortium. It helps all of us to use geo-spatial and location information as any other type of information for more and more online services. Traditionally, geographic information was developed and used by the geographic community only. Today, the adoption of OGC's interoperability specifications provides the foundation to geo-enable any business, and gives this legacy real value. This is the goal of "enabler" COTS which allows dynamic distribution of existing heterogeneous information. Interoperability becomes a key success factor, as more and more strategic decisions are made based on location.
OGC membership allows companies of any size to gain access to key industry topics and essential feedback on both technical and market requirements. OGC is the best place for a company like IONIC to meet tomorrow's business partners and to get in touch with major technological players and communities of users. We enjoy being a member.
Co-founder & Business Manager IONIC Software s.a.
TC Representative to the MC/PC, Head of Belgium delegation at ISO TC211 Belgium
The Open GIS Consortium welcomes our members who've joined us since November 2001.
University of Manchester School of Engineering, Environmental
Water Engineering Research Group
Digital Earth Systems, Inc.
British Columbia Institute of Technology
OGC IN THE NEWS
-OGC in the Press
XML: Wherever You Go, There You Are
This article examines GML in the Ordnance Survey.
IT-Director.com, Dec 2001
Speaking a Global Map Language
Geography Markup Language (GML) would enable agencies to better exchange map data.
Brian Robinson, Federal Computer Week, Dec. 3, 2001
Making a Plan
The crux of the I-Team Initiative is the I-Plan, a comprehensive effort to compile, maintain and finance spatial data in each specific I-Team area.
Heather B. Hayes, Federal Computer Week, Oct 2001
Working off the Same Map
OMB's I-Team initiative pulls together federal, state and local mapping efforts.
Heather B. Hayes, Federal Computer Week, Oct 2001
- OGC Press Releases
Dec 12, 2001 Dr. Mike Jackson Joins OGC Board
Dec 12, 2001 CANRI, Australian Spatial Data Infrastructure Team Join OGC Web Services Initiative
Dec 07, 2001 BAE SYSTEMS Increases Its Focus on Support to Interoperability
Dec 04, 2001 OGC Advances Location Services Interoperability at "GIS In Telecoms 2001"
February 4-8, 2002 Palisades, New York, USA
OGC Technical and Planning Committee Meetings
Hosted by Columbia Earth Institute of Columbia University at Lamont-Doherty Earth Observatory
March 17-20, 2002
Tampa, Florida, United States, GITA Annual Conference
April 8-12, 2002
Washington D.C., United States, OGC Technical and Planning Committee Meetings
June 3-7, 2002
London, England,OGC Technical and Planning Committee Meetings,
Hosted by Cadcorp, Ltd.
July 15-17, 2002
Zurich, Switzerland SVG Open/Carto.net Developers Conference
OGC Events Calendar
For further info on events please contact Greg Buehler,
gbuehler [at] opengeospatial [dot] org.
Please send comments and suggestions to:
Editor, OGC News
adena [at] opengeospatial [dot] org
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Copyright 2001 by the Open Geospatial Consortium, Inc.